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- Nobel prizewinner Omar Yaghi says his invention will change the world (paid): 2026 Jan 27

- The daring idea that time is an illusion and how we could prove it (paid): 2026 Jan 26

CHEMISTRY | JAN 27, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

Nobel prizewinner Omar Yaghi says his invention will change the world

Chemist Omar Yaghi invented materials called MOFs, a few grams of which have the surface area of a football field. He explains why he thinks these super-sponges will define the next century

By Karmela Padavic-Callaghan

Christopher Michel/Contour RA by Getty Images

Civilisations name their ages after materials. In school, we learn about the Stone Age, the Bronze Age – and we are currently in a silicon age characterised by computers and phones. What might define the next age? Omar Yaghi at the University of California, Berkeley, thinks a family of materials he helped pioneer in the 1990s has a good shot. They are metal-organic frameworks (MOFs), and working out how to make them earned him a share of the 2025 Nobel prize in chemistry.

MOFs, and their cousins covalent organic frameworks (COFs), are crystalline materials, but what sets them apart is their incredible porosity. In 1999, Yaghi and his colleagues made a splash when they synthesised a zinc-based material called MOF-5 that was so riddled with pores that a couple of grams of it had an internal surface area comparable to a football field (see diagram below). The inside of the material was effectively an awful lot larger than its outside.

For decades, Yaghi has been at the forefront of making new MOFs and COFs, a discipline known as reticular chemistry, and working out just how useful they can be. Because other molecules can be sucked into these materials’ abundant pores, they turn out to be great at harvesting water from arid desert air, absorbing carbon dioxide from the atmosphere and much more. Yaghi spoke to New Scientist about why he is optimistic about this work, the past, present and future of reticular chemistry – and why he thinks the age of these materials is dawning.

Karmela Padavic-Callaghan: What originally grabbed you about reticular chemistry?

Omar Yaghi: When we started working with MOFs, we didn’t think we would be addressing societal challenges – it was an intellectual challenge. We wanted to find a way to make materials one molecule at a time, like constructing a building, or programming molecules like Lego. But this was a really formidable chemistry challenge. For many people, it was taken as an article of faith that this would not work, that pursuing it was a waste of time.

Why did designing materials in this way seem so impossible?

The main challenge with building materials in a rational way is that, typically, when you mix the chemical building blocks, you end up with them joining together in a way that is disordered and hard to characterise. This is not surprising given the laws of physics that tell us that nature tends towards high entropy or disorder. Instead, we wanted to end up with crystals, with ordered matter that has a repeated, periodic structure.

It’s a bit like asking a room of kids to make a perfect circle: it takes hard work, and when they do it, they can still dissociate or “un-hold” hands and then take too long to complete the circle again. To put it another way, we were trying to do what nature does when it crystallises diamonds over the course of billions of years – but in a day. But I knew deep down inside that anything can be crystallised if you know how.

In 1999, your instincts were proven right and your team reported on the synthesis of MOF-5, which was unprecedentedly stable. Did you anticipate that a material like it could eventually become useful?

We identified a solvent that could help synthesise stable MOFs and were then able to understand how it worked. We realised that having its molecules in the mix was absolutely crucial for modulating the tendency towards disorder. Thousands of researchers have used this method since.

At the beginning, I was just excited to make beautiful crystals. Then we saw their great properties and could say, “Wow, what can we do with this?” And once you know how much porosity these materials have, you immediately think about trapping gases. These materials encompass compartments of space where a molecule of water or carbon dioxide or something else can sit.

Tell me about how you think about making these materials these days.

When I’m cooking, I don’t like having to do more than three steps, and I don’t use butter. So, the challenge is how to get a master dish in so few steps and only use healthy ingredients. This philosophy also spilled into my chemistry. In other words, I want to keep the process simple and only use the chemicals we really need.

The first step is choosing the backbone of the material. The second is deciding on the size of its pores. You can also do chemistry on the skeleton and add molecules to it, to help capture other compounds into the pores. The third step is to let carbon dioxide or whatever you built the material for get sucked in. That’s how easy and how complex the process is.

What sort of new technologies has this process allowed you to pursue?

Once you learn how to design materials at the molecular level, that’s the ultimate achievement, a geologic shift. My vision, and the vision for the company I founded in 2020, Atoco, is to go from the molecule to society, to look at places where there is no material for some task or it is doing it badly, then rationally design a better one. As we become better at making materials, we will improve societal standards.

In 2024, we reported the best yet material for capturing carbon dioxide, called COF-999. It captures it from air and we tested it for more than 100 cycles of capturing then [expelling] carbon dioxide here in Berkeley. Atoco aims to use reticular materials such as COF-999 to build carbon-capture modules that could operate in industrial settings, but also in residential buildings.

We have also developed materials that can capture thousands of litres of water per day from the atmosphere. This is the basis for our devices that can extract water vapour from air even in places where humidity is lower than 20 per cent, such as desert areas in Nevada. I think in 10 years, water harvesting will be everyday technology.

MOFs have a crystalline structure that is riddled with tiny internal pores

EYE OF SCIENCE/SCIENCE PHOTO LIBRARY

There are other technologies that can capture water, such as devices that condense atmospheric vapours, and there are other devices that can capture CO2, too. How do MOFs and COFs compare?

We have so much control over the chemistry that we can make our devices in a sustainable fashion. They could work for many, many years, and at the end of the journey of the MOF part of the device, you can disassemble it in water in such a way that no MOF escapes into the environment. So, in a world where MOFs are scaled to multi-tonne levels and used in many different applications, we will not face a “MOF waste problem”.

And these devices can be a lot more energy-efficient because we worked out, for example, how to use ambient sunlight to make water harvesters release water. For carbon-capture devices, we could also use waste heat from industrial processes [to get them to release CO2], which would make them more economical and sustainable than competing technologies.

But there are still challenges with scalability, making materials chemically stable and having precise control over how and when they release the molecules that they suck in from the environment. For instance, we can already make MOFs at the scale of tonnes, but we cannot yet make COFs in such large quantities. Within a few years, I suspect that we will go bigger. As another example, for even better water harvesting, we need to optimise how materials hold onto the water – it cannot be too strong nor too weak.

We are now also using artificial intelligence agents to help optimise MOFs and COFs and make the design process as efficient as possible. It is, in general, easy to make a MOF or a COF, but it can take a year to make one with specifically optimised properties. If an AI agent can do it more quickly, that would be transformational. I went into the lab and told everyone to try using large language models and we already doubled the rate at which we can make some new MOFs.

What are the uses for reticular chemistry that you think more people should be excited about?

Reticular chemistry is currently a massive field: millions of new MOFs can still be made, and chemists are behaving a little like children in a candy shop. One attractive idea is using MOFs to do what enzymes do when they speed up chemical reactions, a process called catalysis, which can help synthesise useful chemicals, such as in drug development. We have MOFs that can do what enzymes can do, but they could last and work for longer than enzymes. This is ripe to be exploited for biological applications, for therapeutics, in the next decade or so.

But I think the next-best use cases will come from “multivariate materials”, which is research that you don’t hear much about because it is only going on in my lab. Here, we want to make MOFs that don’t have the same structure through and through, but have massively different environments within them. We can make them from different modules that are “decorated” with different compounds, so inside the material, there would be very different microenvironments that would make specific molecules do specific things. In experiments, we have already been able to leverage this to make materials that absorb gases more selectively and efficiently. This is also a shift in chemists’ mindsets. Chemists are not used to thinking about making heterogeneous or uneven materials, but we want a very ordered skeleton for a material combined with very heterogeneous guts.

What makes you optimistic about the future of MOFs and COFs? “Miracle materials” have come and gone before.

We have just scratched the surface here and we are not short on ideas. The field has been expanding since the 1990s. Often, research interests decline over time, but that has not happened here, and if you look at the growth in patents related to MOFs and COFs, you also see an exponential increase there. People are still seeing ways not just to solve intellectual challenges in chemistry, but to find new applications and uses for these materials. And I love how this work combines organic and inorganic chemistry into one field, and it is now also bringing in engineering and AI. It’s become more than chemistry: this type of research is a real scientific frontier.

I think we are going through a revolution. It does not always feel like that, but something special is going on. We can design materials like we’ve never done before, and connect them to uses like we have never done before.

PHYSICS | JAN 26, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

The daring idea that time is an illusion and how we could prove it

The way time ticks forward in our universe has long stumped physicists. Now, a new set of tools from entangled atoms to black holes promises to reveal time’s true nature

By Zack Savitsky

Ryan Wills for New Scientist/Adobe Stock

Rushing to get to work in the morning, we grab our coat, bag and keys and – invariably – steal a glance at the clock to check that we are running on time. The passing of time is so integral to our day-to-day lives that we can’t afford to ignore it from one hour to the next.

So far, so completely obvious. Yet if we pause to ask what physics has to say about why time flows at all, we find it struggles. Albert Einstein’s ideas warped time, quantum theory barely considers it, and no other facet of modern physics can satisfactorily explain it. “It’s one of the biggest mysteries of science,” says Natalia Ares at the University of Oxford.

Now, though, one of the most audacious proposals for how time really works is getting a second look. Back in the 1980s, physicists sketched out the hypothesis that time is an illusion, conjured from an essentially timeless universe by the strange workings of quantum mechanics. Back then, this idea, known as the Page-Wootters mechanism, impressed many – but it was beyond any experimental test. Forty years later, however, new research into the working of clocks is showing how we might finally probe this elegant proposal and revealing the mysterious role that black holes may play in the ticking of time.

If you were to survey the laws and equations of modern physics, the only clue that time flows in just one direction would come from the second law of thermodynamics, which states that entropy, a measure of disorder, tends to increase. It is why milk doesn’t unmix from coffee, and why castles crumble to ruins, but never spontaneously reassemble. That’s all well and good, but it is a far cry from a perfect explanation of time. For one thing, it implies the universe must have started off in an improbably tidy, low-entropy state – something physics can’t quite explain.

Then came Einstein’s general theory of relativity, which fused time and space into a flexible, four-dimensional fabric that warps under the influence of mass and motion. It leads to mind-bending effects, like the fact that time ticks faster atop a mountain, where gravity is weaker, than at sea level. And in extreme scenarios – like objects hurtling near light speed – two observers might even disagree about the order of events. This made sense, Einstein argued, only if the past, present and future all exist alongside one another like pages bound in a flipbook.

If relativity muddies time’s meaning, quantum mechanics nearly erases it. In quantum theory, time isn’t an integral part, but rather a kind of bolt-on that ticks in the background – and many quantum processes could, in theory, run just as easily backwards in time as forwards. Quantum theory deals in measurements – and unlike properties such as position, momentum and energy, time can’t be measured directly. You can measure where a particle is, but never when it is. “Time is the odd man out,” says Nicole Yunger Halpern, a physicist at the National Institute of Standards and Technology in Maryland. “Time looks more like an element of the theory that we somehow put in by hand than some natural property of quantum systems that we can measure.”

All this has led some physicists to ask a radical question: what if time is just an illusion that emerges from a deeper structure that we have yet to glimpse?

The Page-Wootters mechanism

It was precisely this question that compelled physicists Don Page and William Wootters to propose what they thought was the true face of time in 1983. Like Einstein, they imagined the entire universe as a single stationary object. But instead of a flipbook, they hypothesised that the universe was a giant quantum wave function: a sprawling mathematical structure that encoded everything the universe could possibly be. Every particle and every direction it could travel, as well as every field, were all folded up into one package. On its own, this wave function didn’t tick or move – it was timeless.

But then Page and Wootters split this frozen structure in two. One half, they said, described all the “stuff” we could ever observe: the matter, the motion, the mess of reality. The other half acted as a kind of internal clock. The two would be connected through a strange feature of quantum physics called entanglement, an effect that links two objects so intimately that changes in one instantly affect the other. Page and Wootters showed that their entanglement would allow for an appearance of time to emerge.

Time might emerge from the strange quantum phenomenon of entanglement

koto_feja/Getty Images

Imagine a manuscript of a story lying on a table. It is timeless: its beginning, middle and end are already written. But for the story to make sense, we must read the pages in the correct order. Page numbers, for instance, provide that structure, linking characters, plot and action across otherwise static snapshots. Page and Wootters proposed that the universe might work in a similar way. The part of the wave function that encodes the content of reality is like the words on the page. The other part, the clock, is like the page numbers. Only together do they create the experience of time unfolding. “I think it’s a very compelling explanation,” says Simone Rijavec at Tel Aviv University in Israel.

We even have hints that the idea isn’t just pie in the sky. In 2024, Paola Verrucchi at the National Research Council of Italy (CNR) built a simple mathematical model based on the Page-Wootters mechanism by entangling a clock made from an array of tiny magnets with a quantum system that behaved similarly to a spring. From the outside, this system was static, staying in a fixed quantum state with constant energy. And yet, relative to the clock, the spring appeared to stretch and contract, exhibiting a time-like sequence of changes. Crucially, the effect still held when the set-up was enlarged, suggesting that the illusion of time generated by entanglement could persist even in the larger-scale realm of classical physics. “You can derive all the equations of motion that we know work [from the model],” says Verrucchi. In other words, the basic premise of the Page-Wootters mechanism appears to hold up.

But from the start, the Page-Wootters mechanism left many questions unanswered. At the most basic level, Page and Wootters never really specified what their “clock” was supposed to be, or whether it bore any resemblance to the physical clocks that populate our everyday life. Nor did they fully explain how our familiar experience of time might emerge from this web of quantum entanglement. Entanglement is usually a fragile, easily broken link, so if we are continually entangled with the universe’s internal clock, why does time appear to flow smoothly, without our observations ever disrupting it?

How do quantum clocks work?

For decades, the Page-Wootters mechanism was firmly rooted in the realm of theory and thought experiments. Now, however, a growing number of studies are dragging it into the lab and asking testable questions. The impetus for this has come in part from an unexpected quarter: quantum technology. Over the past decade, quantum computers, sensors and other devices have matured beyond the proof-of-concept stage and into a phase where further progress depends on ever finer control.

Timekeeping presents a critical bottleneck here. For most of the history of physics, clocks were taken for granted. But in 2017, a team of researchers showed that timekeeping carries a small but real cost. They demonstrated that clocks aren’t really passive measuring devices, akin to a ruler, but more like engines – in the sense that keeping time requires work and produces heat. In classical settings, this heat is negligible, but in the quantum realm, even the slightest puff of heat can throw off the ticking of these clocks.

Marcus Huber at the Technical University of Vienna, Austria, collaborates with Ares to study what happens when clocks are pushed to these quantum limits. “We’re trying to zero in on what even is a clock, what are the resources it needs to run, and what are its limitations?” says Huber.

Clocks don’t need to have two hands that revolve in a circle. Historically, Chinese civilisations kept time by burning a maze of incense

Jennie Hills/Science Museum Group

To understand how, it helps to broaden our picture of what a clock can be. A clock needn’t have hands or gears. In principle, you could tell the time by how quickly your coffee cools or how many wrinkles appear on your face, for example. At its core, “a clock is something that creates an irreversible event that can be recorded in a register”, says Huber. Irreversible events are ones that raise entropy, which is why clocks – even our smallest ones – emit heat. But it also means you can study how much entropy a clock produces to understand the time it keeps.

Over the past few years, Huber and his collaborators have done just that with the simplest clocks imaginable, consisting of only a few atoms. In 2021, they characterised the direct trade-off between a clock’s precision and the amount of entropy it produces. Generally, the more frequently a clock ticks, the more entropy it generates. A clock that divides a minute into 60 perfectly spaced ticks generates more entropy than one that slices that minute into three. And last year, they built a clock that ticks using random quantum processes, allowing it to run while generating almost no entropy at all. But even then, there was a catch. Reading time from the clock – extracting information from it – produces entropy.

These experiments aren’t just about improving timekeeping. Huber sees them as tools for probing deeper questions. “The hope is that such operational definitions of clocks [help us] learn something about the nature of time itself.”

That includes revisiting the Page-Wootters mechanism. Huber aims to treat this entangled, universe-spanning clock not as a purely mathematical object, but as a physical system that is subject to the same rules as any other timekeeper. If those rules – about precision, entropy and reversibility – can be pinned down across clocks of all kinds, then even the abstract Page-Wootters construction could be tested in principle.

Some physicists imagine the past, present and future as a series of static frames that exist side by side simultaneously

Nick Harrison/Alamy

Huber’s group is now designing experiments to do just that, using entangled quantum systems, such as clouds of atoms, that could mimic the Page-Wootters mechanism in the lab. By measuring the entropy emitted by their clocks, they will be able to get at foundational questions, like whether time flows smoothly or in discrete steps in such quantum systems, he says.

It is a collision of the two worlds that Huber straddles: one devoted to taking clocks apart, the other to decoding the nature of the time they keep. “Each of them has their own understanding of time,” he says. “And I think we’re slowly seeing a little crossover. It’s an exciting time to be thinking about time.”

Huber isn’t the only one pushing the idea forward. Rijavec and his colleagues have also been investigating how a Page-Wootters clock could be made real. “We started with an ideal clock, but now we want to go in a realistic direction,” says Rijavec. Last year, he explored how to read a Page-Wootters clock without destroying the delicate entanglement that gives it structure. He’s now looking into how a patchwork of many imprecise clocks, rather than one ideal one, could keep time for the whole universe.

Black holes as the universe’s quantum clock

Meanwhile, Verrucchi thinks she has already stumbled upon nature’s supreme clock. In previous work with Alessandro Coppo at CNR, she examined the requirements of an idealised Page-Wootters clock. She knew it would need three things: enough energy to track the evolving system’s dynamics; isolation, so its evolution wouldn’t be scrambled by outside noise; and the ability to become entangled with whatever it is keeping time for.

In a paper put online this year, Verrucchi and Coppo proposed that there was something in nature that ticks all three boxes: black holes. These energetic objects have gravitational fields around them that are so strong that not even light can escape their event horizon, making them essentially non-interacting. Yet, as Stephen Hawking showed in the 1970s, they can still become entangled with the outside world. A pair of quantum particles might form at the black hole’s horizon, with one falling in and the other escaping as radiation. In this way, the inside of the black hole becomes linked to the outside – perhaps just enough to act as a timekeeper. “It’s a perfect clock,” says Verrucchi. “You cannot interact with it, but at the same time, you can be entangled with it.”

So, could the clock half of the Page-Wootters mechanism be nothing less than the universe’s black holes? It is a bold idea, but Verrucchi hopes that one day it could be tested. In principle, the lessons from quantum clocks could offer a way in. If a black hole really can act as an almost-ideal clock, then, just like a quantum clock, its timekeeping should leave fingerprints in the thermodynamics and entropy of the radiation it emits – in how quantum correlations spread, and how information gets scrambled. That’s the next step for Verrucchi and Coppo: to analyse the thermodynamics of their black hole model and look for parallels with the entropy dynamics seen in quantum clocks.

Link to video: https://www.youtube.com/watch?v=_zycDCk5bss

To Verrucchi, all these developments strengthen the general notion that time isn’t fundamental, but is emergent – and they have led her to an even deeper idea. Many physicists suspect the second law of thermodynamics has something to do with the flow of time, because of its irreversible nature – order tends to turn to chaos. But while this law says the universe’s entropy won’t decrease, it doesn’t forbid it from remaining constant – thus, it still doesn’t explain why time flows.

There is, however, one truly irreversible facet of nature, Verrucchi points out. Before a measurement, a quantum particle exists in a blur of different possible outcomes. Only by measuring it does a particle collapse from a cloud of possibilities to a definite value. No one knows exactly how this collapse happens, but one thing is for sure: it cannot be undone.

Verrucchi now suspects this is key to how time works. The arrow of time, she says, might simply be a record of what has been measured. Like flicking through a cosmic flipbook, we reveal new pages by interacting with the elements of reality – or “making measurements” as a physicist might put it. The act of simply being in the world collapses our quantum reality into a definite state, leaving an irreversible record behind.

And if clocks are physical systems that record measurements – and we are, too – then perhaps we aren’t just observers of time, says Verrucchi, but participants in its making: “You create time when you ask what time it is.”

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ENVIRONMENT | JAN 27, 2026, 12:50 PM EST | VIEW ON NEW SCIENTIST

Amazon is getting drier as deforestation shuts down atmospheric rivers

The amount of rainfall in the southern Amazon basin has declined by 8 to 11 per cent since 1980, largely due to the impact of deforestation

By Alec Luhn

Vast areas of the Amazon rainforest have been burned for cattle ranching

MICHAEL DANTAS/AFP via Getty Images

Deforestation has reduced rainfall over the Amazon, suggesting the rainforest could reach a catastrophic tipping point sooner than expected.

Satellite observations and rain gauge measurements show that the amount of rain falling in the southern Amazon basin declined by 8 to 11 per cent between 1980 and 2019. Tree cover in that part of the Amazon shrank by 16 per cent in roughly the same period, mainly because the forest was slashed and burned for beef cattle ranching.

The northern Amazon basin has suffered far less deforestation and saw only a slight increase in precipitation, which was not statistically significant.

While a recent study linked deforestation to drier weather within 300 kilometres, the new research found this connection across a basin more than 3000 kilometres wide. That shows destroying rainforest can also hurt nearby ranches and soy farms, says Dominick Spracklen at the University of Leeds, UK, who worked on the new study.

“Some people in agribusiness might see a bit of forest as wasted land [they] could go clear,” he says. “That bit of forest is working really hard to maintain regional rainfall that our bit of agriculture is benefitting from.”

Global warming has also been drying the Amazon rainforest, with extreme drought leading to record wildfires in 2024. But atmospheric modelling by Spracklen and his colleagues showed deforestation caused 52 to 75 per cent of the decline in rainfall.

Prevailing winds transport moisture from the Atlantic Ocean that falls as rain over the Amazon. Evaporation and transpiration by plants return three-quarters of that water to the atmosphere. Further downwind, it falls as rain again and returns to the atmosphere for half a dozen cycles or more, fuelling “flying rivers” that carry moisture across the entire rainforest.

If an area of forest is razed, more than half of the rainwater in that area runs off into streams and begins flowing back to the ocean. That starves the flying rivers of moisture and reduces rainfall. It also diminishes the atmospheric instability that leads to storm cloud formation, Spracklen and his colleagues found.

With fewer trees to slow it down, the wind blows faster and carries more moisture out of the region.

Unlike past research, the study marries both data and modelling to explain exactly how deforestation weakens rainfall, says Yadvinder Malhi at the University of Oxford.

“The atmosphere becomes smoother; in some ways it glides. The moisture can travel further out of the forest region because there’s less friction on the ground,” says Malhi. “So there’s some interesting secondary atmospheric processes that aren’t normally captured.”

Scientists are concerned that the combined effects of heat, drought and deforestation could push the Amazon to a tipping point that sees it transform into a savannah, but there is uncertainty on how close this is to happening. Spracklen and his colleagues found that climate models underestimate the impact of deforestation on rainfall by up to 50 per cent, which suggests the rainforest could reach this tipping point much sooner than expected.

A study last year found a 37 per cent chance of some Amazon dieback by 2100 if global warming, which currently stands at 1.4°C, reaches 1.5°C. While that wouldn’t necessarily mean the rainforest will turn to savannah, it would mean a shrubbier forest holding fewer species and less carbon, Spracklen says.

“The Amazon is more sensitive than we think, which is bad news,” he says. “Maybe we’re closer to a deforestation threshold than we thought. But I think there’s lots of uncertainty.”

Journal reference:

Nature Communications DOI: 10.1038/s41467-026-68361-z

COMMENT HEALTH | JAN 27, 2026, 12:44 PM EST | VIEW ON NEW SCIENTIST

To halt measles' resurgence we must fight the plague of misinformation

The measles vaccine has prevented 60 million deaths since 2000. So why are so many children around the world missing out on it?

By Michael Le Page

Vaccine uptake is critical for public health

Robin Utrecht/Shutterstock

When I read the 1998 study falsely claiming there was a link between the measles, mumps and rubella (MMR) vaccine and autism, I was shocked. Shocked by how bad the paper was, shocked that it was published in a high-status journal and shocked that journalists reported it so uncritically. And back then, I didn’t even know the study was fraudulent.

Nearly three decades later, the consequences of those bad decisions by doctors and journalists are still reverberating around the world. Due to low vaccination rates driven at least in part by the anti-vax movement, fuelled by that fraudulent paper, six countries have lost their measles-free status, according to the World Health Organization (WHO), including the UK (for the second time), Spain and Austria. Meanwhile, the US is battling its worst outbreak in many decades, and would have lost its own measles-free status soon, had it not withdrawn from the WHO.

Measles is one of the most contagious viruses on the planet. It causes severe complications in around 1 in 5 children, including breathing difficulties, deafness, blindness and brain swelling that can lead to permanent brain damage. Globally, measles killed about 95,000 people in 2024.

It also kills off some of the immune cells that protect us against other infections, lowering people’s immunity for around five years, so its true toll is even higher. Measles is absolutely not an infection that you want to take chances with.

Luckily for us, measles has a weakness: the virus first infects immune cells and travels to the lymph nodes, before spreading more widely around the body. This convoluted route means there are far more opportunities for our immune system to intercept it before people become infectious than with respiratory viruses that mainly infect the cells lining our noses and throats.

This is why the measles component of the MMR vaccine is so effective. It is also clear beyond any doubt that children are much better off being vaccinated than not, and that there is no link with autism. Numerous studies show this, but the one I personally found most convincing is the fact that when the MMR vaccine was withdrawn in Japan, it made no difference at all to the incidence of autism.

But because the measles virus is so contagious, at least 95 per cent of children have to be vaccinated to ensure each infected person will infect fewer than one other person on average, meaning the virus can’t spread. Put another way, if only a small proportion of parents fail to vaccinate their children, measles can make a comeback.

Globally, the picture isn’t too bad – but it could be better. The proportion of children getting a first dose of a measles vaccine rose from 71 per cent in 2000 to 84 per cent in 2010. It then levelled out and dropped a bit during the covid-19 pandemic, but has since recovered. The WHO estimates that between 2000 and 2024, 60 million deaths globally were averted by measles vaccination – a huge triumph.

But in rich countries, we are going backwards. After the false claims made in 1998, MMR uptake levels fell to as low as 80 per cent in England and Wales. By 2013, uptake was back above 90 per cent, but it has been slowly falling ever since. According to a report last year, this latest decline in the UK is due in part to it becoming harder for parents to get their children vaccinated – an issue that needs to be urgently addressed.

But the resurgence of the anti-vaxxers in many countries is definitely part of the problem, with the issue now closely linked to right-wing extremism and promoted on certain social media platforms. I did a quick search for “mmr measles” on Bluesky, and didn’t spot a single anti-vax post in the top results. When I repeated this search on X, many of the results were ludicrous anti-vax nonsense.

When the billionaire owners of social media platforms are in cahoots with the habitual liar who leads the richest country in the world, and who has made an anti-vaxxer health secretary, it is hard to know how to combat all this disinformation.

What’s clear is that this goes way beyond vaccines, with climate science being another crucial area where the lies can crowd out the truth. Governments in Europe and beyond need to get a lot more serious about controlling the infosphere and finding ways to promote sound science and silence the charlatans. No less than the future of humanity is at stake.

HEALTH | JAN 27, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

Our brains play a surprising role in recovering from a heart attack

A newly discovered collection of neurons suggests the brain and heart communicate to trigger a neuroimmune response after a heart attack, which may pave the way for new therapies

By Chiara Marchisio

The brain responds after a heart attack

Science Photo Library / Alamy

Following a heart attack, the brain picks up and acts on signals that come directly from sensory neurons located in the heart. The discovery suggests there is a feedback loop, which involves the immune system as well as the brain, that has an important role in recovery.

“The body and the brain do not exist in isolation. There is immense crosstalk between different organ systems, the nervous system and the immune system,” says Vineet Augustine at the University of California, San Diego.

Augustine and his colleagues knew from previous work that the heart and the brain are linked by cardiac sensory neurons that regulate blood pressure and fainting behaviour.

So they set up an experiment to understand if similar nerves are involved in the response to heart attacks. They made a mouse’s heart transparent by getting rid of the lipids it contains through a cutting-edge technique called tissue clearing, induced a heart attack by blocking blood flow, and then tracked which heart nerves were most called into action.

They found a previously undiscovered cluster of sensory neurons that stem from the vagus nerve and wrap tightly around the heart ventricle’s thick muscular wall, especially where the tissue was damaged by the lack of blood flow. Before the heart attack, there were just a handful of these nerve fibres. After the heart attack, though, the fibres increased severalfold, says Augustine, suggesting the heart actually triggers these neurons to grow following injury.

When Augustine’s team genetically manipulated these nerves to turn them off, preventing them sending signals back to the brain, the heart quickly healed. “The injured area becomes really, really small,” says Augustine. “The recovery was remarkable.”

After heart attacks, patients often have to undergo surgery to restore blood flow to the heart and prevent further tissue damage. A future drug that targets the newly found neurons, Augustine says, could give patients an alternative, particularly if surgery isn’t available immediately.

The researchers also noticed the signals produced by these nerves travelled to cells in a region of the brain that is activated in response to stress, sending the mouse into fight-or-flight response. This, in turn, activated the immune system, directing immune cells to travel to the heart. The immune cells form scar tissue that repairs the injured heart muscle, but too much scarring can alter the muscle’s function and lead to subsequent heart failure. By blocking this immune response early, Augustine and his colleagues showed another way for the mice to heal after a heart attack.

Experiments in recent decades have hinted at communication between the heart, the brain and the immune system during heart attacks. What’s changed is that scientists now have the tools to identify changes in a level of detail that reaches specific populations of neurons, says Matthew Kay at George Washington University in Washington DC, who wasn’t involved in the study.

“This gives us really exciting opportunities to develop new therapies for patients that have heart attacks,” he says, which could potentially include gene therapies.

Doctors regularly prescribe beta blockers to help patients heal from the tissue damage caused during a heart attack. These findings help elucidate that beta blockers may work by targeting part of the nervous and immune system feedback loop that is activated by a heart attack.

“We may already be intervening on [the newly discovered] pathway,” says Robin Choudhury at the University of Oxford, who wasn’t involved in the study.

However, Choudhury adds, this pathway probably doesn’t exist in isolation and is part of a complex picture of responses that we don’t completely understand yet, which involves other immune cells and signals.

Factors like genetic and sex differences, or conditions like diabetes and hypertension could also potentially affect how the newly identified response plays out. This means that, before designing new drugs targeting the pathway, there has to be a way to determine if and when it is active in the wider population, says Choudhury.

Journal reference:

Cell DOI: 10.1016/j.cell.2025.12.058

PHYSICS | JAN 27, 2026, 3:00 AM EST | VIEW ON NEW SCIENTIST

We have a new way to explain why we agree on the nature of reality

An evolution-inspired framework for how quantum fuzziness gives rise to our classical world shows that even imperfect observers can eventually agree on an objective reality

By Karmela Padavic-Callaghan

We can usually agree what objects look like, but why?

Martin Bond / Alamy

Our world seems to be fundamentally fuzzy at the quantum level, yet we do not experience it that way. Researchers have now developed a recipe for measuring how quickly the objective reality that we do experience emerges from this fuzziness, strengthening the case that a framework inspired by evolutionary principles can explain why it emerges at all.

In the quantum realm, each object – such as a single atom – exists in a cloud of possible states and assumes a well-defined, or “classical”, state only after being measured or observed. But we observe strictly classical objects free of existentially fuzzy parts, and the mechanism that makes this so has long puzzled physicists.

In 2000, Wojciech Zurek at Los Alamos National Laboratory in New Mexico proposed “quantum Darwinism”, where a process similar to natural selection would ensure that the states of objects that we see are those that are most “fit” among all of the many states that could exist, and therefore best at replicating themselves through their interactions with the environment on their way to an observer. When two observers that only have access to fragments of physical reality agree on something objective about it, it is because they are both observing one of these identical copies.

Steve Campbell at University College Dublin and his colleagues have now proved that different observers are likely to agree on an objective reality even if the way they gather information about an object – the way they observe it – is not the most sophisticated or optimally precise.

“If one observer captures some fragment, they can choose to do whatever measurement they want. I can capture another fragment, and I can choose to do whatever measurement that I want. So how is it that classical objectivity arises? That’s where we started,” he says.

The researchers recast the problem of objectivity’s emergence as a problem in quantum sensing. If the objective fact at hand is, for example, the frequency at which an object shines light, then the observers must obtain accurate information about that frequency, in a similar way to how a computer equipped with a light sensor would. In the best-case scenario, this set-up could capture super-precise measurements and quickly reach a definitive conclusion about light’s frequency – a scenario quantified by a mathematical formula called “quantum Fisher information”, or QFI. In the new work, the researchers used QFI as a benchmark against which they could compare how different, less precise observation schemes reach the same, accurate conclusions, says team member Gabriel Landi at the University of Rochester in New York state.

Strikingly, the team’s calculations showed that for big enough fragments of physical reality, even observers doing imperfect measurements could eventually gather enough information to reach the same conclusions about objectivity as the ideal QFI standard.

“A silly measurement can actually do as well as a much more sophisticated measurement,” says Landi. “That’s one way of seeing the emergence of classicality: when the fragments become big enough, observers start agreeing even with simple measurements.” In this way, the work offers another step towards understanding why when we observe our macroscopic world, we agree on its physical properties, such as the colour of a cup of coffee.

“The work highlights that perfect, ideal measurements are not required,” says Diego Wisniacki at the University of Buenos Aires in Argentina. He says that QFI is a mainstay of quantum information theory but it hadn’t been introduced into quantum Darwinism before, so it could bridge this still rather theoretical quantum framework with well-established experiments – for example, in quantum devices with light-based or superconducting qubits.

“This is one more ‘brick’ in our understanding of quantum Darwinism,” says G. Massimo Palma at the University of Palermo in Italy. “And is a way [of studying it] which is closer to an experimentalist’s description of what you actually observe in a lab.”

The model the researchers used in their study is very simple, so while their method may open doors to new experiments, calculations for more complex systems will be needed to put quantum Darwinism on even firmer foundations, he says. “It would be a really great breakthrough if we could go beyond simple toy models,” says Palma.

Landi says the researchers are already interested in turning their theoretical investigations into an experiment – for example, with qubits made from trapped ions, where they could see how the timescale for the emergence of objectivity compares to the specific times during which those qubits are known to keep their quantumness.

Journal reference:

Physical Review A DOI: 10.1103/hn78-7xx3

HUMANS | JAN 26, 2026, 3:00 PM EST | VIEW ON NEW SCIENTIST

Stick shaped by ancient humans is the oldest known wooden tool

Excavations at an opencast mine in Greece have uncovered two wooden objects more than 400,000 years old that appear to have been fashioned as tools by an unknown species of ancient human

By Michael Marshall

Artist’s reconstruction of a Palaeolithic woman making a digging stick from an alder tree trunk

G. Prieto; K. Harvati

The oldest known wooden tools have been found in an opencast mine in Greece. They are 430,000 years old and were made by an unidentified species of ancient human – perhaps the ancestors of Neanderthals.

Prehistoric wooden artefacts are “very scarce”, says archaeologist Dirk Leder at the Lower Saxony State Office for Cultural Heritage in Hannover, Germany, who wasn’t involved in the study. “Every single find is welcome.”

Yet it is likely that our extinct relatives used wooden tools for millions of years. “It might be the oldest type of tool that anybody used,” says Katerina Harvati at the University of Tübingen in Germany. Poor preservation and the difficulty of identifying wooden artefacts have limited our knowledge of them.

Harvati and her colleagues discovered the tools at a site called Marathousa 1, which they first identified in 2013 in the Megalopolis basin in southern Greece. An opencast lignite mine had exposed layers of sediments, some of them almost a million years old. “It allows us to access time periods and sediments that would otherwise have been buried,” says Harvati.

During excavations between 2013 and 2019, the team found the near-complete skeleton of a straight-tusked elephant (Palaeoloxodon antiquus) that showed signs of butchery, along with remains of other animals and plants and more than 2000 stone tools. The animals and plants are a mix of aquatic and near-aquatic species, including hippopotamuses, indicating that the site preserves an ancient lake shore.

The researchers dated Marathousa 1 using multiple methods, including identifying traces of past shifts in Earth’s magnetic field and testing when grains were last exposed to sunlight. In 2024, they concluded that the remains are about 430,000 years old, dating back to a time when the climate was forbidding. “It’s one of the worst glacial episodes in Pleistocene Europe,” says Harvati. The Megalopolis basin may have acted as a refuge, with a cold but less extreme climate.

Out of 144 pieces of wood, the team identified two tools. One is an 81-centimetre-long stick made from the trunk of an alder tree. Most of the bark had been removed and there are many carving and chopping marks, indicating that the wood had been purposely shaped. One end is more rounded and may be a handle, while the other end is flattened and shows signs of fraying and splintering.

It may have been used for digging, says Harvati, for example to find underground tubers that could be used as food. But it may also have had other uses. She points out that it was found within the elephant bones, hinting that the hominins might have used it to help process the carcass. “I don’t really know what they were doing with it,” she says.

The second wooden tool found at Marathousa 1, the function of which is unclear

N. Thompson; K. Harvati

The second tool is more enigmatic. It is a small piece of willow or poplar, 5.7cm long and 1.2 cm to 1.5 cm across. Again, it has been stripped of bark and has marks that suggest it was purposely shaped. “This is a completely new type of wooden tool,” says Harvati. It may have been used for retouching stone tools, but “we don’t really know what it was for”, she says.

The stick is an extremely convincing example of a wooden tool, says Leder. He is less sure about the second item because it isn’t clear what it might have been used for. “My first question would be, is this actually a complete item, or is it rather a fragment of something?” he says.

No hominins have been found at Marathousa 1. Given the age of the site, it is probably too early for our species, and possibly too early for the Neanderthals who lived in Europe before us. “A first hypothesis is that what we have here is a type of pre-Neanderthal, or Homo heidelbergensis,” says Harvati. But it would be foolish to assume, she says, because Greece was a place where many groups of hominins passed through.

Other examples of ancient wooden tools include the Clacton Spear in the UK, which may be about 400,000 years old. Wooden spears found in Schöningen, Germany, were thought to be of a similar age, but Leder says multiple dating methods have put them closer to 300,000 years old and a study published in May 2025 even suggested they were just 200,000 years old. The only wooden artefacts older than those from Marathousa 1 are from Kalambo Falls in Zambia, dating back 476,000 years. These seem to be the remains of larger structures or buildings.

Journal reference

PNAS DOI:

Discovery Tours: Archaeology and palaeontology

New Scientist regularly reports on the many amazing sites worldwide, that have changed the way we think about the dawn of species and civilisations. Why not visit them yourself?

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HEALTH | JAN 26, 2026, 11:16 AM EST | VIEW ON NEW SCIENTIST

Menstrual pad could give women insights into their changing fertility

A woman's fertility can be partly gauged by levels of a hormone that reflects how many eggs she has. Now, scientists have built a strip that changes colour according to levels of this hormone, which is present in period blood, into a menstrual pad

By Helen Thomson

Menstrual pads can non-invasively collect information on a woman’s fertility

Shutterstock/Connect world

An at-home test built into a menstrual pad could help women track their fertility using their period blood, offering a non-invasive way to monitor changes over time, without the need for repeated blood tests or clinic visits.

For many women, their fertility remains a mystery until they try to conceive. If they encounter difficulties, clinical tests can offer insights.

These tests can measure levels of anti-Müllerian hormone (AMH), a common marker of “ovarian reserve” – a rough indication of the number of eggs remaining. In adults, AMH levels decline with age, so high levels indicate a plentiful egg supply. A below-average level can signal a diminished egg reserve or early menopause.

Traditionally, AMH is measured using a blood test in the clinic or via a finger-prick test at home. In both cases, the sample must be sent to a lab for processing before results are returned.

Now, Lucas Dosnon at ETH Zurich in Switzerland and his colleagues have developed an easy-to-use test that provides immediate results using menstrual blood.

The test is a lateral flow assay (similar to a covid-19 test) that uses tiny, gold-coated particles covered with antibodies that bind specifically to AMH. When the test is dipped in menstrual blood, the interaction of the hormone and particles creates a visible line on the test strip. The darker the line, the higher the AMH.

Although the results can be estimated by eye, the researchers have trained a smartphone app to analyse a photograph of the test strip to provide a more precise reading. When they used their approach to test menstrual blood containing known concentrations of AMH, the results closely matched those obtained from lab-based tests.

The team has also integrated the test into a menstrual pad, which would allow AMH levels to be measured passively during a period. This could provide meaningful insights into ovarian reserve over time, potentially revealing trends that would be missed by a single test.

“We believe that this work could be transformative for women’s health,” says Dosnon, who suggests the test could enable frequent screening of ovarian health for many purposes, including during IVF or for the detection of fertility conditions other than declining ovarian reserve. High AMH levels, for example, are associated with polycystic ovary syndrome and, in rare cases, granulosa cell tumours, which affect the ovaries. “Menstrual blood is an underutilised resource that actually holds a lot of promises for health monitoring as a whole,” says Dosnon.

Richard Anderson at the University of Edinburgh, UK, points out that clinical interpretation is a challenge with any kind of home medical test, because analysing the results isn’t always straightforward, and that no AMH test can tell you about the quality of eggs. He also wonders whether women would choose this test over established ones. “Is getting a reliable blood test such a burden?” he asks.

In response, Dosnon says the test isn’t intended to replace clinical lab tests, but rather to offer an alternative that addresses some of the challenges faced in women’s health monitoring and research, thanks to its non-invasiveness, ease of use and low cost.

Reference:

medRxiv DOI: 10.64898/2025.12.18.25342545

SPACE | JAN 26, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

The best map of dark matter has revealed never-before-seen structures

JWST has created a map of dark matter that is twice as good as anything we have had before, and it may help unravel some of the deepest mysteries of the universe

By Leah Crane

The dark matter distribution observed by the Hubble Space Telescope (left) and by the James Webb Space Telescope (right)

Dr Gavin Leroy/Professor Richard Massey/COSMOS-Webb collaboration

Scientists have created the best ever map of dark matter using subtle distortions in the shape of about 250,000 galaxies. It could help us understand some of the biggest mysteries in the cosmos.

Dark matter is extraordinarily hard to map because, true to its name, it doesn’t emit any light that we can detect. It only interacts with regular matter through its gravitational pull, so that is what researchers use to figure out where it is. Jacqueline McCleary at Northeastern University in Massachusetts and her colleagues used the James Webb Space Telescope (JWST) to do so, examining an area of sky slightly bigger than the full moon.

“It is a very high-resolution picture of the scaffolding of this little corner of the universe,” says McCleary. The resolution of the map is about twice as high as previous ones made with the Hubble Space Telescope, and it includes structures much further from Earth.

To make this map, the researchers examined the shapes of about 250,000 galaxies – but it isn’t their intrinsic shape that is interesting. “Those galaxies are basically the cosmic wallpaper,” says Liliya Williams at the University of Minnesota, who wasn’t involved in the analysis. Instead, what’s important is how the gravity of dark matter between the telescope and the “wallpaper” warps the light of the galaxies, in a process called gravitational lensing: the further the average shape of the distant galaxies is from circular, the more dark matter lies between them and us.

By analysing these differences in shape, the researchers mapped out huge clusters of galaxies, along with the filaments of the cosmic web that connects them. Some of these structures didn’t match up with anything we had previously seen while observing regular, or luminous, matter, indicating that they must be dominated by dark matter. “To identify many of these structures over a wide field, gravitational lensing is one of very, very few techniques, and definitely the best,” says Williams.

This is important because dark matter makes up about 85 per cent of the total matter in the universe, so it is crucial to the evolution of not only galaxies and galaxy clusters, but also the cosmos as a whole. Building a map of its distribution could help us nail down how it behaves and what exactly it is made of, says Williams.

“Not only is it an observational coup, but in turn it’s going to enable a lot of other analysis – cosmological parameter constraints, the connection between galaxies and their dark matter haloes and how they grow and evolve over time,” says McCleary. These cosmological parameters include the strength of dark energy, the mysterious force causing the universe to expand at an accelerating rate.

For now, it appears that the JWST map matches our current standard model of the universe, known as lambda-CDM, but there are many in-depth investigations of the data yet to be done that are certain to provide new insights, says McCleary. “Although at a glance it’s a match for lambda-CDM, I’m not giving up yet – I’m withholding judgment until our analysis is finished.”

Journal reference

Nature Astronomy DOI: 10.1038/s41550-025-02763-9

ENVIRONMENT | JAN 26, 2026, 7:00 AM EST | VIEW ON NEW SCIENTIST

Termination shock could make the cost of climate damage even higher

Solar geoengineering could halve the economic cost of climate change, but stopping it would cause temperatures to rebound sharply, leading to greater damage than unabated global warming

By Alec Luhn

Solar geoengineering could save the ice sheets – but stopping it could be catastrophic

Martin Zwick/REDA/Universal Images Group via Getty Images

Solar geoengineering could be even more costly than unabated global warming if it is cut off suddenly, leading to a “termination shock” of rapidly rebounding temperatures.

As the rate of greenhouse gas emissions continues to climb, interest is growing in solar radiation modification (SRM) to cool the planet, such as by spreading sulphur dioxide aerosols in the stratosphere to block sunlight.

But solar geoengineering would need to continue uninterrupted for centuries, or the warming that was “masked” would come roaring back at a faster rate. Known as termination shock, this rebound would give humans and animals little time to adapt to the heat and could trigger climate tipping points like ice sheet collapse.

Based on established relationships between temperature increases and GDP loss, Francisco Estrada at the National Autonomous University of Mexico and his colleagues modelled the risks of climate inaction compared with those of solar geoengineering.

If humanity fails to reduce fossil fuel emissions, temperatures could reach a median 4.5°C above pre-industrial levels by 2100, causing economic damages of $868 billion, the researchers estimate. A hypothetical stratospheric aerosol injection programme beginning in 2020 that kept temperature rise to about 2.8°C could halve those damages.

But if the aerosol programme was suddenly terminated in 2030 and temperatures rebounded 0.6°C over the next eight years, damages could top $1 trillion by the end of the century. While the numbers might be higher or lower in real life, “the message doesn’t really change”, says Estrada. “It would be much worse if we have a termination shock than if we did nothing, if we had unabated climate change.”

The study is innovative in estimating damages based not just on total warming but also on how fast it arrives, says Gernot Wagner at Columbia University in New York.

Solar geoengineering “is riskier than it looks at first glance”, he says. “That is the contribution here.”

The Silicon Valley start-up Make Sunsets has already released more than 200 balloons of sulphur dioxide into the stratosphere to sell emission offsets. That included a launch in Mexico that prompted the government to threaten a geoengineering ban.

The Israeli company Stardust has raised $75 million and lobbied the US government about solar geoengineering. Two-thirds of scientists expect large-scale SRM this century, according to a survey carried out by New Scientist last year.

To cool Earth by 1°C, at least 100 aircraft would have to spread many millions of tonnes of sulphur dioxide in the stratosphere every year without interruption by political disputes, wars, pandemics or other black swan events.

Today, major players like the US are actively undermining international cooperation on climate policy, but this kind of cooperation would be required to avoid termination shock and make SRM a net benefit, the researchers conclude.

Graphing different combinations of parameters, they found aerosol injection is only likely to reduce climate damages if the probability of its termination in any given year is just a few tenths of a per cent, or if that termination could be tapered off over more than 15 years.

If countries slash emissions and only a small amount of geoengineered cooling is needed, aerosol injection could be beneficial at termination probabilities up to about 10 per cent. Although a 10 per cent probability of termination in any given year means a 99.9 per cent chance of failure over the course of a century, the temperature rebound should be small in this low-emissions scenario.

This need for international climate cooperation reveals what Estrada calls the “governance paradox” of solar geoengineering. “The probability of failure must be very, very low; you have to be able to manage if things go wrong and importantly you have to have very good governance for mitigation,” he says. But “if you’re able… to manage the problem of global mitigation of greenhouse gases, then you wouldn’t really need SRM”.

These findings suggest research into solar geoengineering is not necessarily a “slippery slope” to its deployment, as some have argued, says Chad Baum at Aarhus University, Denmark. Funding for the new work came from The Degrees Initiative, which finances geoengineering research in more vulnerable low-income countries.

“You want to have all steps of the research… have more input from the communities affected,” says Baum, who also collaborates with Degrees.

But given that emissions and climate impacts are increasing, more research is still needed on the trade-offs of geoengineering, says Wagner. “We are forced against the wall,” he says.

Journal reference:

Environmental Research Climate DOI: 10.1088/2752-5295/ae33df

LIFE | JAN 23, 2026, 3:00 AM EST | VIEW ON NEW SCIENTIST

Why did magic mushrooms evolve? We may finally have the answer

Many species of fungus across the world produce psilocybin, a chemical with psychedelic effects in humans, but its evolutionary purpose may be to deter mushroom-munching insects

By James Woodford

Many mushroom species produce the psychoactive compound psilocybin

YARphotographer/Shutterstock

Magic mushrooms have been giving humans mind-altering experiences for thousands of years, but the real reason fungi evolved these hallucinogenic chemicals may have been as a bioweapon against insects that feed on them.

Psilocybin is the active ingredient in numerous species of magic mushrooms, which are found on every continent except Antarctica and have a long history of use by shamans in traditional cultures. Recently, researchers have been investigating psilocybin as a possible treatment for a range of mental health conditions from depression to post-traumatic stress disorder.

The drug exerts its psychedelic effects mainly by binding to serotonin receptors in the human brain. But it has been unclear why numerous species of fungus evolved to synthesise compounds that resemble animal neurotransmitters, says Jon Ellis at the University of Plymouth in the UK. “There were suggestions that psilocybin might have a defensive role against invertebrate fungivores, but these hypotheses had never been tested,” he says.

To investigate the effects of psilocybin on insects, Ellis and his colleagues mixed dried, powdered magic mushrooms (Psilocybe cubensis) into food given to fruit fly (Drosophila melanogaster) larvae. They followed the young larvae through their life cycle to see how many survived, how quickly they developed and whether the adults were smaller than average or showed signs of developmental differences.

They also prepared liquid extracts from the mushrooms, added some sucrose and exposed larvae to these extracts for an hour before filming how they moved. It was “a bit like a bath in a sweet magic mushroom soup”, says team member Kirsty Matthews Nicholass, also at the University of Plymouth.

“By measuring how fast they crawled, how far they travelled and how coordinated their movements were, we could quantify short-term effects on the insect nervous system,” says Nicholass.

The larvae raised on food containing magic mushrooms survived at far lower rates than larvae given normal food. At lower doses, survival to adulthood dropped by more than half, and at higher doses only about a quarter of the larvae survived.

“Even among those that did make it through development, the effects were clear: adult flies were smaller, with shorter bodies and asymmetries between the left and right wings, which is a classic sign of developmental stress,” says Nicholass. “They crawled shorter distances, spent less time moving overall and showed more erratic turning behaviour. In practical terms, this means the insects were slower and less coordinated.”

But it is unlikely that insects would have a psychedelic experience like those humans have, she says. “What our results suggest is that compounds like psilocybin interfere with basic insect physiology and behaviour in ways that are likely harmful rather than mind-altering.”

The team also collected seven mushroom species from Dartmoor, UK, and analysed the invertebrate DNA present on the samples. This revealed that the psilocybin-producing fungi collected hosted a distinct group of insects from most of the other fungi sampled, suggesting that psychedelic compounds may play a role in shaping which insects can live in or feed on them, the researchers say.

However, there were some unexpected results, indicating that psilocybin’s role is more complicated than the results first suggest. For example, fruit flies with reduced levels of the serotonin receptor that psilocybin normally interferes with suffered worse effects.

The researchers say other hypotheses about the evolution of psychedelic fungi should also be tested, such as the idea that psilocybin deters slugs and snails or these fungi manipulate invertebrates to help them disperse spores.

Fabrizio Alberti at the University of Warwick in the UK says the experiment shows that even mushrooms that don’t make psilocybin can produce other metabolites that interfere with insect pupation rate and survival.

“Further studies using pure psilocybin on insects will be needed to pin down the ecological role of psilocybin and investigate if this hallucinogenic compound may have evolved as an insect defence,” says Alberti.

The study highlights the major challenges in exploring the evolutionary role of psilocybin-producing fungi, says Bernhard Rupp at the University of Innsbruck, Austria.

“There are many ways in which mushrooms producing psilocybin and other exotic compounds might gain an evolutionary benefit, such as deterring consumption by insects or snails,” he says.

Reference:

bioRxiv DOI: 10.64898/2025.12.17.694186

Insect and ecosystems expedition safari: Sri Lanka

Journey into the richly biodiverse heart of Sri Lanka on this unique entomology and ecosystems-focused expedition.

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SPACE | JAN 23, 2026, 5:00 AM EST | VIEW ON NEW SCIENTIST

SpaceX’s Starlink dodged 300,000 satellite collisions in 2025

The company’s mega-constellation is having to perform a huge number of manoeuvres to prevent a collision in Earth orbit

By Jonathan O’Callaghan

A long-exposure photograph in the northern hemisphere showing satellites in the night sky

Alan Dyer/VWPics/Universal Images Group via Getty Images

A report filed by SpaceX with the US Federal Communications Commission (FCC) in late December reveals some startling information – including that its Starlink satellites had to perform about 300,000 collision-avoidance manoeuvres in 2025.

Starlink is a mega-constellation of satellites that beams the internet to the ground. The first Starlink satellites were launched in 2019; they now number about 9400, accounting for 65 per cent of all active satellites in orbit.

The FCC requires SpaceX to publish an update every six months on Starlink’s approach to safety, given that two satellites could produce thousands of pieces of debris if they were to collide in space, potentially rendering parts of Earth’s orbit unusable or leading to a cascade of collisions.

In its latest report, filed on 31 December, SpaceX said that its Starlink satellites performed about 149,000 collision-avoidance manoeuvres from June to November 2025. Such manoeuvres are performed when two satellites are deemed to be passing too close to each other and have a reasonable risk of collision.

The industry standard is to manoeuvre when there is a 1 in 10,000 risk of collision, but SpaceX is more conservative and manoeuvres at a risk of 3 in 10 million.

In addition to the 144,000 manoeuvres previously reported by SpaceX from December 2024 to May 2025, this amounts to about 300,000 in 2025, an increase of about 50 per cent from 200,000 manoeuvres in 2024. “That’s a huge amount of manoeuvres,” says Hugh Lewis at the University of Birmingham, UK. “It’s just an incredibly high number.”

Most other satellite operators in the US and abroad don’t publish their manoeuvre figures, but a typical satellite pre-Starlink might have performed a handful of manoeuvres a year. Per SpaceX’s figures, it is performing up to 40 manoeuvres per year, per satellite.

Lewis says the company is on track to perform 1 million manoeuvres every year by 2027, with several other mega-constellations in the US and China also being deployed – meaning the number of potential collisions is going to grow. “From a physics point of view, it’s not good,” says Lewis. “We are moving ourselves towards a pretty bad scenario in orbit. It is not sustainable.”

In its latest report, SpaceX also revealed, for the first time, repeated encounters with other satellites. It singled out a Chinese satellite, called Honghu-2, as having more than 1000 close approaches with its Starlink satellites, likely because they operate in similar orbits.

“It highlights how SpaceX really owns that orbit,” says Samantha Lawler at the University of Regina in Canada, with most of its Starlink satellites operating at an altitude of between 340 and 570 kilometres. “According to the Outer Space Treaty, everybody is supposed to have access to all parts of space, but they’ve kind of occupied it.”

SpaceX also revealed details of a Starlink satellite that exploded in December, releasing dozens of pieces of debris. It said the cause was a “suspected hardware failure” and added it had “identified and removed” the components responsible from future Starlink designs.

Starlink uses an autonomous system to dodge collisions and cope with the huge number of manoeuvres required. However, SpaceX said it had one incident in which a spacecraft operated by the Japanese company Astroscale “performed an unannounced manoeuvre”, which could have raised the risk of collision with a Starlink satellite.

Astroscale disagrees with that version of events. A spokesperson said the company publicly shared the planned manoeuvre ahead of time and it was “conducted in compliance with Japanese on-orbit servicing guidelines”. SpaceX didn’t respond to a request for comment.

However, it is the overall number of manoeuvres that is the most eye-catching statistic. “They’re doing all these manoeuvres and they’re doing them perfectly,” says Lawler. “But if they make a mistake, we’re in really big trouble.”

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SPACE | JAN 26, 2026, 3:00 AM EST | VIEW ON NEW SCIENTIST

Mars's gravity may help control Earth’s cycle of ice ages

Despite its small size, Mars seems to have a huge impact on the orbital cycles that govern Earth’s climate, especially those that cause ice ages

By Leah Crane

Mars has a surprisingly large influence on Earth’s climate

NASA/JPL/Malin Space Science Systems

Compared with Earth, Mars is tiny, yet it seems to have an outsized effect on our planet’s climate cycles. Similar small planets could affect the climates of worlds beyond our solar system, which we must begin to take into account when evaluating their potential habitability.

Stephen Kane at the University of California, Riverside, and his colleagues found this effect by running simulations of the influence Mars would have on Earth’s orbit if it were a different mass, from 100 times its actual mass to if it were gone entirely. “I came to this from a perspective of scepticism, actually, because I had trouble believing that Mars, which is only a tenth the mass of Earth, could have such a profound effect on Earth’s cycles, so that’s what motivated this study to turn that knob of Mars’s mass and see what happens,” says Kane.

Earth’s climate has many long-scale cycles based on the eccentricity of its orbit – how stretched out its path around the sun is – and the tilt of its axis. These orbits, governed by the gravity of the sun and the other planets in the solar system, govern such crucial events as the timing of ice ages and the intensity of seasonal changes.

One of the most influential is known as the grand cycle: over the course of 2.4 million years, the ellipse of Earth’s orbit around the sun elongates and shortens again. This affects how much sunlight Earth’s surface gets at any given time, regulating the timing of long-term changes in climate.

The researchers found that when Mars was removed entirely, the grand cycle disappeared, along with another cycle in Earth’s eccentricity that lasts about 100,000 years. “It’s not to say that if we removed Mars then Earth wouldn’t have ice ages, but it would change that whole landscape of the frequency at which ice ages and related climate effects are occurring,” says Kane.

When Mars’s simulated mass was increased, these cycles became shorter and more intense. But a third eccentricity cycle lasting about 405,000 years, which is governed mainly by the gravitational pulls of Venus and Jupiter, remained regardless of Mars’s mass, so the Red Planet isn’t all-powerful, but it is more influential than anyone expected.

A more subtle effect is Mars’s influence on Earth’s tilt, which normally wobbles back and forth over a period of about 41,000 years. Kane and his colleagues found that Mars seems to have a stabilising effect on this cycle, with it occurring less frequently if Mars had extra mass and more frequently if Mars got smaller.

We can’t say exactly what Earth would be like if Mars weren’t there or if it were much larger in size, but there would certainly be some changes. As the search continues for Earth-like worlds with a climate suitable for life as we know it, it seems the influence of smaller planets is larger than scientists realised. “We really need to know the orbital architectures of exoplanet systems really well to be able to reasonably have a grasp on the possible climate fluctuations on those planets,” says Sean Raymond at the University of Bordeaux in France.

Understanding that architecture will be tough, though. “This is more of a warning than anything else: we can’t ignore the smaller objects, even though they are quite difficult to find, because those smaller planets like Mars are really having a bigger impact than we thought,” says Kane.

Journal reference

Publications of the Astronomical Society of the Pacific DOI: 10.1088/1538-3873/ae2800

HEALTH | JAN 23, 2026, 2:00 PM EST | VIEW ON NEW SCIENTIST

Bone cancer therapy unexpectedly makes tumours less painful

A drug that kills cancer cells by puncturing them comes with an additional benefit: tests in mice suggest it reduces the growth of pain-sensing nerves around tumours

By Carissa Wong

An artist’s impression of nanomedicine in action

ALFRED PASIEKA/SCIENCE PHOTO LIBRARY

Cancer that spreads to bones can be deadly, and it also tends to be painful. Now, a drug seems to address both problems by disrupting the interplay between nerves and tumours, suggesting the approach could provide a more comfortable form of cancer therapy.

“This highlights a new, exciting paradigm where a single cancer therapy can improve mortality and quality of life at the same time,” says William Hwang at Harvard University, who wasn’t involved in the new research.

Between 65 and 80 per cent of people with breast or prostate cancer that has spread to distant sites in the body end up with cancer in their bones. As these skeletal tumours grow, they tend to stimulate nearby pain-sensing nerves.

Radiotherapy, where X-rays are fired at tumours, and chemotherapy, which targets rapidly dividing cells with powerful drugs, are commonly used to shrink such bone growths. But pain often persists because any remaining cancer cells continue to interact with nerves. What’s more, conventional therapies often damage healthy tissue – leading to prolonged use of painkillers like opioids, which carry the risk of addiction, says Jiajia Xiang at Zhejiang University in China.

Now, Xiang and his colleagues have developed a “nanotherapy” made of tiny, fatty capsules containing DNA encoding for the protein gasdermin B, which kills cells by puncturing holes in them. The drug was designed to produce gasdermin B only in cancer cells and not healthy ones, based on the idea that tumour cells can be distinguished from other cells because they have higher levels of certain molecules called reactive oxygen species. The capsules also contain a chemical called OPSA that boosts the body’s natural anti-cancer immune response.

To put their drug to the test, the researchers injected breast cancer cells into one leg each of several mice. Once the cancer cells had grown into bone tumours, each mouse received either the complete nanotherapy, a simpler form of the nanotherapy that contained OPSA but not the gasdermin B gene, or a control saline solution. All treatments were injected into the tail every other day for five days.

Two weeks later, the tumours in the complete nanotherapy group were 94 per cent smaller than those in the control group, on average, while this figure was about 50 per cent in the simpler nanotherapy group. After another couple of weeks, all of the mice that received the complete nanotherapy were alive, whereas just 60 per cent of the mice in the simpler nanotherapy group had survived and only 20 per cent of the control mice did. As expected, the therapy directly killed tumour cells and provoked an anti-tumour immune response, says Xiang.

But the team also noticed that the mice receiving either form of the nanotherapy used their cancerous limbs substantially more than those in the control group, with the complete nanotherapy group seeing larger benefits. This suggested that the nanotherapy might reduce pain associated with bone tumours. When the researchers analysed tumour samples collected from the mice, they were surprised to find that both the nanotherapy treatments reduced the density of nerve cells, or neurons, within the cancerous growths.

The nanotherapy seems to do this by increasing the cancer cells’ ability to uptake calcium ions, which nerves require to grow and transmit pain signals to the brain. “The idea is the cancer cells essentially act as a sponge for all the local calcium, and that depletes the calcium available to nearby sensory neurons,” says Hwang. Further research is needed to tease out exactly how the nanotherapy may be altering calcium uptake in the cancer cells, which could reveal ways to more effectively target this potential pathway, says Hwang.

In another experiment, the team found that the nerves surrounding the tumour actually helped it grow, suggesting the nerve-related effects not only relieved pain, but also slowed the growth of the tumours – although to what extent is unclear, says Xiang.

Together, the findings support the growing idea that targeting the nervous system could transform cancer treatment, says Hwang. But it is generally easier to treat cancer in mice than humans, due in part to differences in the anti-cancer immune response of the rodents and humans, he says. Xiang hopes to start human trials in between five and 10 years.

Journal reference:

Science Advances DOI: 10.1126/sciadv.ady1292

LIFE | JAN 23, 2026, 12:00 PM EST | VIEW ON NEW SCIENTIST

Sea turtles may be more resilient to global warming than we thought

An “epigenetic” adaptation could prevent large numbers of loggerhead turtles from hatching as female due to climate change – a threat that was feared to lead to population collapse

By Chris Simms

A young loggerhead turtle in the Caribbean Sea near the Bahamas

WaterFrame/Alamy

Sea turtles may be better able to cope with climate change than we had thought. Biologists are concerned that the reptiles might face extinction because warmer conditions will encourage most turtle eggs to develop into females. But it turns out the animals have a genetic safety net that could help them retain a more even balance between sexes even as temperatures rise.

“We believe we have uncovered the capacity of turtles to adjust to the environment they are in,” says Chris Eizaguirre at Queen Mary University of London.

The sex of baby sea turtles isn’t set by a sex-determining chromosome – as happens in many animals, including humans – but by the temperature inside the nest. Lab studies have shown that, at lower nest temperatures, more hatchlings will be male and at higher ones, more will be female, leading to fears that global warming will cause ever more turtles to hatch as female.

For example, a 2018 genetic study found that about 99 per cent of young green turtles (Chelonia mydas) aged between about 4 and 20 originating from warmer Great Barrier Reef nesting sites in Australia were female. Modelling based on such results has led to concerns that, without enough males, sea turtle populations will collapse.

Yet the actual state of affairs upon hatching is a mystery because you can’t tell what sex a turtle is until it is several months old unless you kill it to check, so field data on hatchling sex is scant.

To get around this, Eizaguirre and his colleagues have run lab and field experiments with loggerhead turtles (Caretta caretta).

In the first part of their work, they collected a total of 240 eggs from seven loggerhead nests on beaches in Palm Beach county, Florida. They put the eggs in artificial incubators at one of three temperatures: 27°C (81°F), a male-promoting temperature; 30°C (86°F), a “pivotal temperature for equal numbers of males and females; and 32°C (90°F), which should result in females.

When the hatchlings were between 1 and 3 days old, the team collected blood samples and then reared the turtles in captivity for months until they were large enough for sex verification via keyhole surgery and a laparoscopic camera.

Comparing genome sequencing data gleaned from the blood samples with the sex identification revealed that, regardless of the temperature at which the eggs had been incubated, male and female turtles each had different patterns in the activity of hundreds of genes because of an epigenetic process known as DNA methylation. Some 383 genes were hypermethylated in females – meaning they were less active than expected – and 394 were hypermethylated in males. Many of these genes have documented roles in sex development. This meant the researchers could tell the sex of a baby turtle just from a blood sample.

The team used this knowledge in a field study by collecting 29 newly laid loggerhead turtle egg clutches on the beaches of Sal Island in Cape Verde off the coast of West Africa. They divided each clutch, burying one half in a protected area at a depth of 55 centimetres – where it would be cooler – and the other 35 centimetres down, where it would be warmer, and monitored the temperatures.

When the researchers sequenced blood cell samples from 116 hatchlings, half from the “cool” depths and half from the “warm” ones, they found more males than expected given the temperatures that the eggs had experienced. In fact, models based on the incubation temperature overestimated female hatchling production by between 50 and 60 per cent.

This suggests that, in addition to providing a tool for sexing baby turtles, the work shows there are molecular mechanisms that help turtles cope with changes in climate by altering how sensitive the development of their sex organs is to temperature, says Eizaguirre.

“We are not saying that there is no feminisation because there is, and we’re not saying that climate change does not exist because it is there and it’s accelerating,” he says. “What we are saying is that when the populations are large enough, when there is sufficient diversity, then it looks like the species [can] evolve in response to the climate they live in.”

The work backs up recent evidence by a team including Graeme Hays at Deakin University in Australia showing that more male sea turtles are hatching than predicted if it is assumed that temperature is the only driver of sex determination. These results indicate how the pivotal temperature at which the turtle sex ratio is 50:50 can be adapted to local conditions, says Hays.

Turtles also have other mechanisms to mitigate the impacts of warming, he says. These include nesting earlier in the year and patterns of migration to breeding areas reducing the impact of feminisation. “Female turtles generally do not breed every year, but males travel to breeding grounds more often than females,” says Hays. “So, the breeding sex ratio is more balanced than the actual adult sex ratio.”

Such behavioural adaptations are good, says Eizaguirre, but the hatchlings are still exposed to extreme heat, which leaves lasting DNA methylation changes, so signs of molecular adaptation are even better news for these vulnerable reptiles.

Reference:

bioRxiv DOI: 10.64898/2026.01.06.697884v1

HEALTH | JAN 23, 2026, 10:00 AM EST | VIEW ON NEW SCIENTIST

Why singing, dancing and engaging with art is good for your health

Whether it be singing, dancing or crafting, engaging in the arts is good for our health, and we're beginning to understand how this behaviour affects our biology

By Helen Thomson

A night at the theatre could do you a world of good

MIGUEL RIOPA/AFP via Getty Images

Getting involved in the arts isn’t just a pleasurable pastime; it also appears to keep us healthier – and now we may know why. In the largest study of its kind, scientists have shown that engaging in creative activities is linked to beneficial changes in proteins involved in reducing inflammation and keeping the brain healthy.

“We have discovered a whole host of new biological pathways that help to explain the relationship between the arts and health outcomes,” says Daisy Fancourt at University College London.

Over the past decade, evidence has been accumulating that taking part in musical, theatrical or other creative arts can have powerful health benefits. Dance programmes, for example, help people with Parkinson’s disease walk, while children who engage with the arts have a lower risk of depression.

Previous research also suggests that people who are more involved in the arts tend to have lower levels of inflammation, which is linked to better physical and mental health. But most of these studies examined only a handful of markers in the blood, limiting their use. Now, technological advances have made it possible to measure hundreds of proteins and integrate that data into large population studies. This approach, known as proteomics, builds a detailed picture of how our behaviours influence our biology.

Using this method, Fancourt and her colleagues analysed data from around 6000 UK adults, based on a one-off blood sample, examining how engagement in the arts is related to 184 proteins associated with multiple systems in the body and brain.

The team created a measure for how engaged in the arts each person was by combining the frequency of their engagement with the diversity of their activities, and found that the more a person engaged with the arts – such as dancing, singing, reading, practicing photography, crafting and attending the opera – the more likely they would have specific increases or decreases in 18 proteins.

Using follow-up data, the researchers also showed that those who were more engaged in the arts had a lower future risk of several conditions, including heart disease, type 2 diabetes, arthritis, depression and dementia. Crucially, they showed that the protein changes explained 16 to 38 per cent of the association between arts engagement and better health outcomes, even after accounting for confounding factors, such as income and education.

Some of the proteins affected are involved in metabolism, while others keep brain cells healthy. Several were also linked with pathways that increase anti-inflammation processes and reduce levels of inflammatory proteins. “So it might be that the arts are stimulating a rebalancing of the inflammatory system,” says Fancourt.

“While it has long been assumed that participation in arts activities benefits health and well-being, the underlying mechanisms have remained unclear,” says Daryl O’Connor at the University of Leeds, UK. Although the results will need replication in other populations, he says the study is exciting and highlights new opportunities for studying how our behaviours influence our health.

Carmine Pariante at Kings College London says the findings are consistent with the protective effects of arts and culture on mental and physical health. However, he points out that the study presents a biological snapshot at only one point in time, so it is unclear how much arts exposure we need to generate this protective effect.

One potential next step, says Fancourt, is to carry out causal studies, such as monitoring specific proteins before and after people partake in the arts.

Reference:

medRxiv DOI: 10.64898/2026.01.09.26343769

ENVIRONMENT | JAN 23, 2026, 8:00 AM EST | VIEW ON NEW SCIENTIST

Hybrid megapests evolving in Brazil are a threat to crops worldwide

Two extremely damaging crop pests have interbred to create hybrids resistant to more than one pesticide that could cause serious problems in many countries

By Michael Le Page

A corn earworm (Helicoverpa zea) larva feeding on a cotton plant

Debra Ferguson/Design Pics Editorial/Universal Images Group via Getty Images

Two “megapests” that are already a major problem for farmers worldwide, the cotton bollworm and the corn earworm, have interbred in Brazil and swapped genes conferring resistance to pesticides. The hybrid strains that are evolving could devastate soya and other crops in Brazil and around the world if they can’t be controlled, threatening global food security.

“It has the potential to be an enormous problem,” says Chris Jiggins at the University of Cambridge.

In particular, many countries import soya from Brazil to feed both people and animals. “It kind of feeds the world,” says Jiggins.

More than 90 per cent of the soya grown in Brazil is genetically modified Bt soya containing a built-in pesticide. If yields fall due to pests becoming resistant, it would lead to yet more increases in the price of many foods. It could also increase deforestation and greenhouse gas emissions, as farmers compensate by clearing more farmland.

The corn earworm (Helicoverpa zea) is a moth native to the Americas whose caterpillars eat most parts of plants. They are particularly damaging to corn, but also feed on many other plants including tomatoes, potatoes, cucumbers and aubergines (eggplants).

In Brazil, H. zea wasn’t a major problem for farmers growing soya because it tends not to feed on the crop. But then, in 2013, the cotton bollworm (Helicoverpa armigera) was detected in Brazil. H. armigera is a relative of H. zea that is widespread across Eurasia. The two moths have been described as megapests because they are so damaging and hard to combat.

“They are pretty exceptional pests, so I think that’s justified,” says Jiggins. “Controlling the movement of the moths is almost impossible. They move very large distances.”

H. armigera also feeds on a wide range of plants and, unlike H. zea, it thrives on soya, so it caused huge problems for farmers when it reached Brazil. “It was billions of dollars of cost to Brazilian agriculture,” says Jiggins.

This was largely solved by the introduction of Bt soya, which is genetically modified to produce a protein made by the soil bacterium Bacillus thuringiensis that is toxic to most insects.

It was thought that H. armigera and H. zea couldn’t interbreed, but in 2018 genetic analysis revealed a few hybrids between the species. Jiggins and his colleagues have now analysed the genome of nearly 1000 moths collected in Brazil over the past decade.

They found that a third of H. armigera now carry genes providing resistance to the Bt toxin – and they got these genes from H. zea. Bt maize was first introduced in North America in the 1990s, where some H. zea strains evolved resistance. These resistance genes seem to have spread to South America and now crossed species. As yet, the hybrid H. armigera haven’t been a major problem, says Jiggins, but that could change as resistance spreads.

The transfer has gone both ways – nearly all H. zea in Brazil now have a gene conferring resistance to a class of insecticides called pyrethroids that was acquired from H. armigera. “We’re just sort of blown away by how rapidly it’s happened,” says Jiggins.

“With global connectivity and climate change together lowering barriers to species’ range expansions, such megapests are likely to be an increasing global problem, as is the escalating rate of biological invasions more generally,” says Angela McGaughran at the University of Waikato in New Zealand.

Farmers are supposed to plant non-Bt crops alongside Bt ones to create refuges that slow the spread of resistant pests. However, in many countries, these guidelines aren’t followed.

Plant companies are introducing new strains of Bt crops that produce two, three or even five different Bt proteins to combat resistance. “But bringing such new products to market is expensive and slow, so it is best to sustain the efficacy of current Bt proteins with resistance-management tactics, including refuges from exposure to Bt crops,” says Bruce Tabashnik at the University of Arizona.

While hybridisation can spread resistance, Tabashnik says the main issue is evolution within species. In China, strains of H. armigera have independently evolved resistance to the original Bt toxin, he says.

Reference

bioRxiv DOI: 10.64898/2025.12.25.696198

LIFE | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

Stunning images reveal the rich biodiversity of remotest Tanzania

Photographer Frédéric Noy's shots give an insight into life around the rainforests of Udzungwa Mountains National Park – and efforts to protect it

By Michael Le Page

A yellow baboon stands watch

Frederic Noy/Panos Pictures

A young yellow baboon (above) looks out over the Udzungwa Mountains National Park in Tanzania. The Udzungwa mountains are covered by very rich rainforests, but their remoteness means the area was relatively unexplored by biologists until recently.

There are six species of primate living in the park, and for two of these species – the Udzungwa red colobus and the Sanje crested mangabey – the park is their last refuge. Another animal found here, the kipunji monkey, was only recognised as a new species in 2003 – the first new monkey species discovered in Africa since the Sanje crested mangabey in the 1980s.

“To me, it was kind of magic,” says photographer Frédéric Noy, who has taken a series of images giving an insight into the region. It’s not so surprising that we are still discovering new species of fish in the deep sea or tiny insects on land, he says. “But mammals, wow!”

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What’s more, the kipunji were later assigned their own genus, Rungwecebus – the first new monkey genus since 1923. There are estimated to be just 2000 of them remaining, some at Udzungwa and some in another part of Tanzania.

Other recent discoveries in Udzungwa include the giant tree Tessmannia princeps, which can grow as high as 40 metres. It was described as a new species just last year.

On one side of the mountains, native trees are being planted in deforested areas as part of a project known as the Udzungwa Corridor. The aim is to link the Udzungwa Mountains National Park to another reserve nearby.

Workers from the Udzungwa Corridor project cultivating seedlings for an upcoming planting campaign

Frederic Noy/Panos Pictures

The work is being funded by selling carbon credits, allowing local people to earn money if they agree to plant trees on their land. The photo above shows part of one of the nurseries raising trees for the project, alongside some other plants.

Many people around Udzungwa maintain beehives (shown below). The main reason is to provide an extra source of income – the practice has been encouraged to help compensate those who can no longer exploit the resources of the Udzungwa Mountains National Park. Another reason is that hives are thought to deter elephants. There are no elephants living in the park itself, says Noy, but they do sometimes wander in from nearby areas.

This beekeeping project has lined a fence with beehives to deter any passing elephants

Frederic Noy/Panos Pictures

Sugarcane is one of the main crops grown in the area. Below, a truck carrying sugarcane drives through fields of the crops, with the Udzungwa mountains rising in the background. Part of the Sanje Falls are visible.

A truck transports a load of sugar cane, with the Udzungwa Mountains in the background

Frederic Noy/Panos Pictures

HEALTH | JAN 22, 2026, 2:00 PM EST | VIEW ON NEW SCIENTIST

Ancient bacterium discovery rewrites the origins of syphilis

A 5500-year-old genome recovered from human skeletal remains in Colombia may give insights into the early evolution of syphilis and its relatives

By Jake Buehler

Treponema pallidum bacteria cause diseases including syphilis

Science Photo Library / Alamy

Traces of a bacterium related to syphilis have been found in a bone from a person who lived in the mountains of Colombia over 5000 years ago.

The discovery shows that this group of corkscrew-shaped bacteria was infecting humans thousands of years earlier than previously thought, before the rise of intensive agriculture, which many researchers consider a catalyst for the spread of pathogens.

Today, three subspecies of the bacterium Treponema pallidum cause the diseases syphilis, bejel and yaws. The deep history of these ailments is murky, and researchers have debated where diseases like syphilis arose and how they became widespread. Ancient bacterial DNA and markers of infection on skeletal remains lend us some clues, but these are rare and can be ambiguous.

So, when researchers studying the ancient DNA of 5500-year-old human remains in the Bogotá savannah detected the genome of Treponema pallidum in a human leg bone sample, it was a surprise.

“This finding was completely unexpected, because the individual studied had no skeletal evidence of a Treponema infection,” says Nasreen Broomandkhoshbacht at the University of California, Santa Cruz.

It is widely thought that many common diseases started to affect humanity after the dawn of intensive agriculture, when people began living in denser communities. But this individual lived in a very different context, where small hunter-gatherer groups travelled frequently and were in close contact with wildlife.

“Our results can tell us a lot about the long-term evolutionary history of [this bacterium] by revealing a long-standing association with human populations,” says Davide Bozzi at the University of Lausanne in Switzerland.

When Broomandkhoshbacht, Bozzi and their colleagues compared the ancient genome to those of other T. pallidum bacteria, they found it was part of a completely different lineage from any known modern relatives. This indicates that, millennia ago, ancient relatives of syphilis had already diversified in the Americas and were infecting humans, and the team’s analysis suggests they had many of the same genetic features that make today’s strains harmful.

The findings point to an early presence of these pathogens in the Americas, but it is also possible that they have been infecting humans for even longer across the world.

Rodrigo Barquera at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, notes that the ancient strain might belong to an elusive, “missing” pathogen: Treponema carateum, which causes a skin disease called pinta. The bacterium is only known from physical descriptions, not genetics.

Kerttu Majander at the University of Zurich, Switzerland, wonders what additional ancient genomes can tell us. “Were there perhaps many extinct lineages and perhaps different diseases caused by these pathogens in the past?” she says.

For Bozzi, understanding how pathogens evolve to cause diseases like syphilis and yaws is a crucial step in finding the genetic quirks that allow pathogens to infect new hosts and make their associated illnesses more dangerous.

Journal reference:

Science DOI: 10.1126/science.adw3020

LIFE | JAN 22, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

Ancient giant kangaroos could have hopped despite their huge size

Long thought to have walked bipedally, like us, Australia’s extinct giant kangaroos have features that indicate they could also have bounced

By Chris Simms

Procoptodon goliah was 2 metres tall, but it might have hopped

MICHAEL LONG/SCIENCE PHOTO LIBRARY

Even the giant kangaroos that roamed Australia thousands of years ago might have been able to hop, according to a new analysis of bones.

Some of the kangaroos living during the Pleistocene were more than twice as heavy as those that live today. One group, the sthenurines, were so bulky that it was thought they couldn’t possibly hop – they must only have walked on their hind legs.

“Sthenurines are what most people are talking about when they talk about giant kangaroos. They’re the really weird ones,” says Megan Jones at the University of Manchester, UK. “They have these really short, boxy skulls and a single toe on each foot. A large male red kangaroo is the biggest you’re going to get today, at about 90 kilograms, but the largest sthenurine was about 250 kilograms.”

That giant was Procoptodon goliah, the biggest kangaroo species known to have existed, standing at about 2 metres tall. It died out about 40,000 years ago.

However, there has always been debate about how much stress its legs could have taken. To try to get a better handle on this, Jones and her colleagues collated bone measurements from 67 species of macropods, a group that includes existing kangaroos, wallabies, potoroos, bettongs and rat kangaroos, as well as the extinct giant kangaroo lineages.

Taking measurements of leg bones including the femur, tibia and calcaneus – the bone the Achilles tendon inserts into – and data on body mass, the researchers estimated how big the attached tendons would be and how much force they could handle.

“The Achilles tendon in today’s kangaroos is quite dangerously close to breaking, but that serves a purpose,” says Jones. “It allows them to store a lot of elastic energy so they can push into the next hop. If you just took today’s kangaroo and scaled it up, you’d be running into problems.”

But she says the ancient kangaroos aren’t just scaled up. They have shorter feet and a wider calcaneus, for example. The researchers’ calculations show that this would have helped the bones of the giant kangaroos resist the bending moments involved in hopping and accommodate tendons large enough to resist the loads generated during the activity.

“It’s evidence that they weren’t mechanically barred from hopping,” says Jones. “Whether they did hop is a different question.”

Hopping almost certainly wasn’t their primary mode of locomotion, but they might have used it for short bursts of speed, she says.

“The study supports what is now a solidifying picture of the iconic kangaroo hop as a functionally adaptable component of a surprisingly variable gait repertoire,” says Benjamin Kear at Upsala University in Sweden. This repertoire has been key to the ecological success of macropods over many millions of years, he says.

That flexibility is still in evidence today. Although we may think of red kangaroos, for example, as always hopping, they can also walk using their tail as a fifth limb, says Jones. “And tree kangaroos basically do everything under the sun: they walk, they hop, they bound, they walk quadrupedally and even bipedally.”

Reference:

Scientific Reports DOI: 10.1038/s41598-025-29939-7

ANALYSIS: HEALTH | JAN 22, 2026, 7:05 AM EST | VIEW ON NEW SCIENTIST

Does limiting social media help teens? We'll finally get some evidence

A trial will finally reveal whether limiting the time teens spend on social media really does affect their mental health

By Michael Marshall

Teens taking part in a trial that limits their social media use will soon be forced to connect IRL

Daniel de la Hoz/Getty Images

A world-first study will test whether reducing the time teenagers spend on social media really does improve their mental health. But the results aren’t due until mid-2027, by which time further governments may have already imposed out-and-out bans on social media for teens.

The trial won’t tell us whether such bans are worthwhile; robust evidence for this is lacking, yet Australia has already implemented one for under-16s, and the UK government is launching a consultation on a similar move.

What the trial does do is centre the young people themselves, including consulting them on the intervention that would be tested. To date, children and teenagers have been shut out of the design of social media and the discussions around managing it.

“Children absolutely have to be part of this conversation,” says Pete Etchells at Bath Spa University in the UK, who isn’t involved in the study.

“There is a range of evidence that social media is harming individual children and adolescents, including very severe harms,” says Amy Orben at the University of Cambridge, who is co-leader of the trial. What is less clear, she says, is “whether the time spent on social media impacts the wider population of young people”.

Answering this requires large-scale controlled research, so Orben and her colleagues are launching The IRL Trial in Bradford, UK. The aim is to recruit about 4000 12-to-15-year-olds from 10 schools. All the participants will install a bespoke app on their phones that tracks their social media use.

For half of them, the app will also restrict their time on selected social media apps, including TikTok, Instagram and YouTube, but not messaging apps like WhatsApp. “They can only use all of those apps together for a total of one hour, and they also have a nighttime curfew where they can’t use it… between 9pm and 7am,” says Dan Lewer at the Bradford Centre for Health Data Science, who is also co-leader of the trial. This represents a significant cut, he says. “The average daily screen time in this age group, 12-to-15-year-olds, is around 3 hours per day,” says Lewer. The other half of the teens will be able to continue using social media as normal.

Crucially, the kids will be randomised by year group, meaning that in a given school, year 8 might be the control group, while year 9 has their social media use restricted. The aim is to ensure that groups of children experience the same conditions as much as possible. “If you removed or reduced social media use in one child, but their friendship group was still online after 9pm, then they might feel like they’re missing out,” says Orben.

Lewer says the study was designed in collaboration with the teenagers. “They didn’t want us to test a total ban,” he says.

The full-scale study will run for six weeks around October, and the researchers anticipate publishing their first results in mid-2027.

The trial should provide more accurate information than we currently have on how much teens use social media and when, because this will be monitored via the app, rather than relying on self-reporting, says Orben. The team will also collect data on anxiety, sleep quality, time spent with friends and family, well-being, body image, social comparison, school absences and bullying.

It is crucial to learn if restricting or banning social media will help or harm young people, says Etchells. “The honest answer is that we don’t know, and that’s why studies like this are so important.”

But the sheer lack of good-quality research to date makes this trial very welcome. This was underscored by a recent report from the UK’s Department of Science, Innovation and Technology, which highlighted “the lack of high-quality causal evidence linking children’s mental health and wellbeing and their use of digital technologies, specifically, social media, smartphones and AI chatbots”.

It is crucial to work with young people when researching social media, says Margarita Panayiotou at the University of Manchester, UK. For instance, the choice to test restrictions rather than a full ban is more workable, she says, because teens in the studies she has done readily described how they would circumvent such bans. This approach may also be more ethical, because we don’t know if bans would cause harm, she says.

“[Teens] find social media a useful space to understand themselves,” says Panayiotou. But that doesn’t mean that young people don’t also see its drawbacks. “They also talk about mistrusting the platforms themselves” and about “loss of control… they’ll find themselves on social media without realising”. Adolescents have also reported issues such as a fear of being judged online, as well as body comparisons and cyberbullying.

The challenge for governments, say Etchells and Panayiotou, is to force tech companies to make social media safer and healthier for young people.

The Online Safety Act 2023 (OSA) has provisions requiring tech companies like TikTok, Meta – the parent company of Facebook, WhatsApp and Instagram – and Google – which owns YouTube – to take more responsibility for users’ safety. “If the compliance elements of the OSA were actually properly enforced, I think that would go some way to solving some of the issues that we have already,” says Etchells.

Physics

- Let's nitpick about the physics of Stranger Things, not its ending: 2026 Jan 21

PHYSICS | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

Let's nitpick about the physics of Stranger Things, not its ending

Feedback has seen all the fuss about the finale of Stranger Things, but would like to point out that if we're going to dissect the plot, we have bigger things to worry about

By New Scientist

Josie Ford

Feedback is New Scientist’s popular sideways look at the latest science and technology news. You can submit items you believe may amuse readers to Feedback by emailing feedback@newscientist.com

Even stranger things

In common, it seems, with a substantial fraction of the human species, Feedback spent part of our holiday watching the final episodes of Stranger Things. We laughed, we cried, we wondered if it would have even more endings than The Return of the King (it did).

As is almost inevitable these days, a group of fans vocally disliked the finale, and went so far as to create a conspiracy theory about it. According to “Conformity Gate” (don’t blame us, we didn’t name it), the finale wasn’t the real finale – despite lasting more than 2 hours, costing an enormous amount of money and being shown in cinemas. No, a super-secret final episode was going to air in January, which would reveal the true ending. The evidence for this principally consisted of some minor continuity errors, all supposedly hints that everything we saw was an illusion created by the mind-controlling villain Vecna.

Feedback was confident that this was silly even before the supposed extra episode failed to emerge. Not least because the people critiquing the finale were making the wrong critiques. Who cares about the school’s graduation gowns being the wrong colour, when the show’s entire set-up defies physics?

For those who didn’t watch, Stranger Things is set in a town in Indiana, where a government lab has been doing dodgy experiments. This – and there are spoilers ahead, so consider this your warning – has opened gateways to “the Upside Down”, a sort of nasty parallel dimension where another version of the town exists, but everything is mouldy. It eventually transpires that the Upside Down is a wormhole: a gateway to yet another dimension called the Abyss.

So if the Upside Down is a wormhole, what is the red wibbly-wobbly swirly thing hovering in the sky? This gets described as a wormhole, and someone says it contains “exotic matter”, which is the hypothetical substance that would have to exist to stabilise a real wormhole (and which probably doesn’t exist). This is doubly odd, because the passage to the Abyss is in the sky of the Upside Down.

Feedback has been thinking about this for weeks and we cannot work out what the wibbly-wobbly swirly thing is doing there. We also cannot work out why shooting it with a gun causes all nearby matter to liquefy, but blowing it up with explosives destroys the entirety of the Upside Down. And we also cannot work out why destroying this huge wormhole doesn’t release enough energy to wipe out most of the eastern seaboard.

Perhaps the Conformity Gate theorists could turn their attention to solving the physics of the Upside Down. A Nobel prize, or at least an Ig Nobel, could be in the offing.

Sparkle sports

What could be more fun than going to a sports match: being part of a crowd, cheering your players along? Well, what if you were part of a crowd, cheering your players along, while drinking sparkling water? That might be more fun.

Reporter Alice Klein spotted a study about an experiment showing that spectators at a collegiate women’s basketball game enjoyed the game more, and felt greater “perceived unity” with the crowd, if they had drunk some sparkling water, as opposed to still water. “Co-consuming sparkling water serves as an alcohol-free, low-burden ritual to enhance social connection during and after live sport events,” the authors said.

Alice described this as “ridiculous”, to which news editor Jacob Aron retorted: “They studied a whole 40 people, what more do you want?” Readers can make their own judgement as to whether this evidence is convincing. However, Feedback does want to draw readers’ attention to the “Competing interests” statement on the paper, on which we will make no comment whatsoever, and which reads as follows:

“This study was funded by the Asahi Soft Drinks Co., Ltd. W.K. and S.M. are employees of Asahi Soft Drinks Co., Ltd. The authors declare that this has not influenced the research design, methodology, analysis, or interpretation of the results of this study. The sponsor had no control over the interpretation, writing, or publication of this work.”

Prime bloopers

Reader Peter Brooker wrote in to ask if Feedback could start a new section called “AI Bloopers”. He was moved to suggest this after checking a puzzle entry on “a popular search engine”, only for its AI tool to confidently inform him that the first six prime numbers were 2, 3, 5, 7, 9 and 11.

Feedback feels that we have been running this section for some time already, just without an official title. In fact (and here we can give you a little glimpse behind the curtain), we have a recurring conversation with our editor about how often to feature AIs messing up like this. We could fill the whole column with AI bloopers every week, but we worry it would get repetitive.

Still, in the spirit of Peter’s request, we must tell you that the new chancellor of Ghent University, Petra De Sutter, used a generative AI to write her first speech in the role. It contained quotes from Albert Einstein, which the AI had hallucinated.

To quote The Brussels Times: “What’s striking is that De Sutter herself referred to the dangers of AI in her speech. She warned that we should ‘not blindly trust’ the output of AI tools and that AI-generated texts ‘are not always easy to distinguish from original works.'”

Got a story for Feedback?

You can send stories to Feedback by email at feedback@newscientist.com. Please include your home address. This week’s and past Feedbacks can be seen on our website.

Technology

- The internet feels super lonely right now. Here's why (paid): 2026 Jan 21

COLUMNIST TECHNOLOGY | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

The internet feels super lonely right now. Here's why

Almost 80 years ago, sociologists identified a new personality type that is particularly sensitive to loneliness. It's even more relevant today, says Annalee Newitz

By Annalee Newitz

Why does it feel so lonely online these days?

Breana Panaguiton/Unsplash

Right now, I’m glued to my phone. Like most people in the US, I get my news from various apps – social posts, podcasts, newsletters – and when things are blowing up (literally) I can’t look away. People in Minneapolis are posting video updates from protests; experts are publishing essays about international law and the US attack on Venezuela. I have to consume them all! The weirdest part, though, is that the more I watch and read what other people are saying, the lonelier I feel.

This is hardly a new or unique experience. Sociologists have been talking about it for nearly 80 years. In 1950, scholars David Riesman, Nathan Glazer and Reuel Denney published a book called The Lonely Crowd, in which they argued that the rise of consumerism and mass media had led to a new kind of personality type that is deeply sensitive to loneliness. They called this personality “other-directed”, and their descriptions feel startlingly prescient in our era of social media and AI chatbots.

Other-directed people are constantly attuned to what everyone around them is doing, using the preferences of their peer groups to decide what to buy, wear and think. Because their values come from peers, rather than elders or ancestors, they tend to be present-oriented and unconcerned with history. Riesman and his colleagues warned that other-directed people are obsessed with conforming, anxious to be “part of a crowd” and “having fun”. What other-directed people fear more than anything is being alone.

All of these personality traits are immediately recognisable to people dealing with social media, with its peer pressure, parasocial relationships with influencers and – especially these days – surveillance capabilities. We are always watching each other and being watched. And because we fear being alone, companies produce apps designed to fool us into thinking we aren’t. That’s one of the insidious things about AI chatbots, some of which are designed to act like friends.

“ When we cobble ourselves together out of what we think other people want, we hide from something crucial “

There’s a paradox in every other-directed person’s heart. As much as we may want to conform, to be part of the group chat, we also want to feel like we are unique. Riesman and his colleagues explained that consumerism itself assuages this other-directed anxiety by offering “false personalisation”. You experience this when you find yourself choosing between six virtually identical polo shirts at the store. Picking one might make you feel that there’s a special brand out there just for you, but, fundamentally, all those shirts are the same. You wind up wearing a polo shirt just like everybody else.

This kind of false personalisation shows up all the time in the algorithms that shape our experiences online. TikTok and other apps have a “for you” feed full of videos that feel tailor-made for your specific tastes. And yet it is shaped by an algorithm that you don’t control, whose purpose is largely to keep your eyeballs glued to the same app that everyone else is glued to. It is “for you” in the service of conformity.

As other-directed people, we are invited to express ourselves mainly by participating in peer groups or by “joining the conversation”, as so many ads suggest. We turn ourselves into internet content, adding our words and videos to the morass of others online. Be yourself by showing that you are doing what everybody else is doing!

And yet we still feel lonely. Partly that’s because in-person friendships and communities are fundamentally different from online ones. But something else is going on here, and I think it has to do with the personality shifts chronicled in The Lonely Crowd. When we cobble ourselves together out of what we think other people want, we hide from something crucial: our own truly personal, messy, eccentric, non-conformist desires. We can’t connect with other people in a genuine way if we don’t know ourselves.

Riesman and his co-authors suggested two solutions to this other-directed problem. First, we need to take back our leisure hours from the hyper-consumerist sphere of media. All that effort we put into paying attention to our peers is too much like work, they argued, and we need more free play. Which brings me to their second suggestion, which is that people – and especially kids – should test out new identities and experiences. Figure out what you enjoy when nobody is telling you what “fun” is supposed to be. Do something you have never done before. Wear something dramatic or silly. Strike up a conversation with a neighbour you have never met. Surprise yourself. And see how it feels to just… experiment.

You won’t figure out who you are from a “for you” feed or a chatbot. So get off your phone, do something unexpected and be yourself for a while.

What I’m reading

Notes From a Regicide, by Isaac Fellman, a fantastical tale of rebellion and family drama.

What I’m watching

Heated Rivalry, because I know how to have fun.

What I’m working on

Researching Sogdiana, my favourite ancient diaspora culture.

Annalee Newitz is a science journalist and author. Their latest book is Automatic Noodle. They are the co-host of the Hugo-winning podcast Our Opinions Are Correct. You can follow them @annaleen and their website is techsploitation.com

Space

- How to spot the lunar X and V (paid): 2026 Jan 21

- Peter F. Hamilton's latest is an epic slice of sci-fi – with one flaw (paid): 2026 Jan 21

- New Scientist recommends Avatar: Fire and Ash – especially the whale (paid): 2026 Jan 21

SPACE | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

How to spot the lunar X and V

Time it right each month, and you can spot two fleeting tricks of light on the lunar surface. Abigail Beall is planning ahead

By Abigail Beall

The lunar X, seen from Tokyo in February 2025

The Yomiuri Shimbun via AP Images/Alamy

The first time I took a photograph of the moon through my telescope was almost a decade ago. It was a very amateur set-up. I held up my phone camera to the eyepiece and after capturing a dozen fuzzy images, my shaky hands managed to stay steady for long enough that I got a clear picture of the moon’s surface. I was so proud of the photo that I posted it online.

I hadn’t realised it back then, but I was photographing the moon during a very specific 4-to-6-hour window that comes around each month. It wasn’t until someone replied to my post that I realised, by sheer chance, I had captured two fleeting features on the lunar surface known as the lunar X and V.

These marks on the surface of the moon are optical illusions, created by the way sunlight hits the rims of specific craters. And they are only visible during the moon’s first quarter phase, when the line between light and shade – known as the terminator – sits at exactly the right spot.

The lunar X (pictured) is, as you might imagine, a bright X shape that appears because light falls on the rims of three craters named La Caille, Blanchinus and Purbach. The V is also bright and comes about because of the way light hits a crated called Ukert and other smaller craters nearby.

To see the lunar X and V, you will need access to a telescope. Other than that, timing is everything. The time to look will always vary depending on where you are in the world – as will the moon’s visibility.

The next first quarter of the moon will be on 26 January at around 5am GMT, but if you live in the UK, the moon will be below the horizon then, so don’t set your alarms. A good place to look from on the night of 25 January into the next morning will be New York, where the first quarter will be around midnight. This means the X and V will be visible from around 10pm to 2am. In other parts of the world, it will be daylight, so the moon won’t be visible. From Sydney, for example, the January first quarter will be at around 3pm.

If you hope to see the lunar X and V, your best bet is to find a first quarter moon that falls within a good window for observing the moon from where you live – in other words, when it’s dark and the moon is high in the sky. You can use software such as Stellarium to check whether the moon will be visible at a specific time and date, and where it will be in the sky.

The next first quarters are on 24 February, 25 March and 24/25 April. If you live in the UK, like me, 25 March is a good one to aim for, since it falls at around 7pm local time.

Knowing how many factors must align for the lunar X and V to be visible, I feel incredibly lucky that the first time I managed to take a photo of the moon’s surface, these two tricks of light happened to be on display.

These articles are posted each week at

newscientist.com/maker

Abigail Beall is the specials editor at New Scientist and author of The Art of Urban Astronomy. Follow her @abbybeall

SPACE | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

Peter F. Hamilton's latest is an epic slice of sci-fi – with one flaw

Peter F. Hamilton’s new book A Hole in the Sky is set on a troubled ark ship hundreds of years into its voyage, with fantastic plot twists and turns. I'm a big Hamilton fan, but one aspect of the novel proved alienating for me, says Emily H. Wilson

By Emily H. Wilson

A Hole in the Sky is told through the eyes of 16-year-old Hazel

Adam Serba/Alamy

A Hole in the Sky

Peter F. Hamilton, Angry Robot

I am a dyed-in-the-wool Peter F. Hamilton fan, so I was really looking forward to his new book, A Hole in the Sky, especially as I always love an ark ship story.

This ship is hundreds of years into its voyage, and its inhabitants have regressed to something like medieval peasantry, living in villages beneath the high-tech towers their ancestors inhabited. We learn about the issues they have faced – a problem with the first planet they were meant to land on, then a mutiny on board – which have left them in dire straits. At the age of 65, every individual must be recycled for the good of the ship. I loved every single thing about this set-up.

All this is told from the first-person perspective of Hazel, a 16-year-old girl. She is getting terrible headaches because there is a literal hole in the hull of the ship (hence the book’s title) and she quickly becomes embroiled in a dramatic chain of events. But there is also time for her to worry quite a lot about boys and clothes, which I found myself not quite buying. Would a girl or woman of any age worry about her outfit when the lives of everyone on her spaceship were at stake and she had a constant headache?

As you may already know, Hamilton is a genius who has made his name writing big sci-fi. My favourites (probably his Void and Night’s Dawn trilogies, plus his Commonwealth Saga duology) are wild, ludicrously inventive, complicated and mind-blowing. I don’t always totally understand them, but I love the ride.

I wasn’t so keen on Hamilton’s recent book Exodus: Archimedes Engine, tied to the upcoming video game Exodus, because I felt there were sequences included only for the game, rather than readers’ enjoyment, but I do appreciate that wasn’t aimed at me. I also get that a master writer might want new challenges. (The second in the series, for those not averse to video game tie-ins, is out later this year. The game arrives in 2027.)

“ If I were a film or TV scout, I could imagine A Hole in the Sky transferring brilliantly to the screen “

All of which brings me back to A Hole in the Sky. I was halfway through when I noticed it was a bit, for want of a better word, childish. Investigating further, I found that the book first came out as an audio-only novel in 2021 – and that it is generally categorised as “young adult”, which means aimed at teenagers.

In an interview in 2020, Hamilton is quoted as saying: “Having a teenager as the main protagonist defines the publishing category, but I’m hopeful that it will appeal to readers of any age.” Personally, I think a young protagonist doesn’t rule out a book being aimed at adults. (I am writing this as someone who has written novels with teenage protagonists.) But will people of any age enjoy this particular book?

The set-up and the plot twists are fantastic, as you would expect from Hamilton. But I wish he had held off from what I think are meant to be “teenage” elements. When my hero is running for her life, I don’t need interludes in which she is thrilled to hold her boyfriend’s hand. I found myself wishing the main character was 65 and about to be recycled – that would have had some heft.

Maybe Hamilton will find a fresh audience with this. If I were a film or TV scout, for example, I could imagine it transferring brilliantly to the screen. A Hole in the Sky is part of a trilogy, with follow-ups due in June and December. As I wrote in my preview of 2026’s new sci-fi books, this rapid schedule is unusual, and I will be intrigued to see how it fares.

Emily also recommends…

Pandora’s Star

Peter F. Hamilton, Pan Macmillan

If you have never tried Hamilton’s classic works, there are many possible entrance points to the different universes he has created, but I suggest Pandora’s Star and its follow-up Judas Unchained (they make up the Commonwealth Saga duology) as a good route in. If you find the phrase “epic space opera” has a nice ring to it, these are probably for you.

Emily H. Wilson is a former editor of New Scientist and the author of the Sumerians trilogy, set in ancient Mesopotamia. The final novel in the series, Ninshubar, is out now. You can find her at emilyhwilson.com, or follow her on X @emilyhwilson and Instagram @emilyhwilson1

SPACE | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

New Scientist recommends Avatar: Fire and Ash – especially the whale

The books, TV, games and more that New Scientist staff have enjoyed this week

By Bethan Ackerley

Oona Chaplin as Varang in Avatar: Fire and Ash

2025 20th Century Studios. All Rights Reserved.

Bethan Ackerley

Subeditor, London

Nobody makes blockbusters like James Cameron. Avatar: Fire and Ash, his third film set on the verdant moon Pandora, is bombastic and beautiful. And from interspecies war to family feuds, there’s also an awful lot going on.

Some 15 years after ex-Marine Jake Sully was adopted by the Indigenous Na’vi, after helping to drive back the human military and fusing with a Na’vi body, he has made a life on Pandora with his partner Neytiri and their children.

But now they are grieving the loss of their eldest son, Neteyam. And their old enemy, Colonel Quaritch, has joined forces with a powerful volcano-dwelling clan of Na’vi, led by Varang (pictured above).

Shakespeare this isn’t (the dialogue is crass, to put it politely), but there is no denying the draw of this meticulously crafted world.

Come for the visuals, stay for Payakan, a member of an intelligent whale-like species called the tulkun and the real heart of the film.

Humans

- Ape-like hominin Paranthropus was more adaptable than we thought (paid): 2026 Jan 21

- Oldest known rock art is a 68,000-year-old hand stencil with claws: 2026 Jan 21

HUMANS | JAN 21, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

Ape-like hominin Paranthropus was more adaptable than we thought

A fossil discovery in northern Ethiopia expands the known range of Paranthropus, a genus of strong-jawed hominins that lived around 2 million years ago, and suggests they lived in a range of habitats

By Michael Marshall

Illustration of Paranthropus hominins, which lived between 2.7 and 1.4 million years ago

JOHN BAVARO FINE ART/SCIENCE PHOTO LIBRARY

For the first time, the remains of ancient hominins called Paranthropus have been found in the remote Afar region of Ethiopia. The discovery dramatically expands the area over which Paranthropus roamed, and suggests they lived in a wide range of ecosystems.

Paranthropus remains are known from eastern and southern Africa, between 2.7 and 1.4 million years ago. They are thought to be closely related to Homo, the group that includes modern humans and Neanderthals. They may have evolved from earlier hominins called Australopithecus.

Zeresenay Alemseged at the University of Chicago in Illinois and his colleagues have been excavating a site called Mille-Logya, in the Afar depression in north-east Ethiopia, since 2012. The Afar is a treasure trove of hominin remains, including many Homo and Australopithecus remains. “Paranthropus had been eluding us,” he says. “We had pretty much concluded that it had never made it that far north.”

On 19 January 2019, Alemseged’s local assistant brought him a part of a lower jawbone, with no teeth. “The first thing that struck me was its size,” says Alemseged. That same day, the team also found the crown of a left lower molar tooth.

A CT scan confirmed telltale Paranthropus traits: not just the size of the jawbone but the proportion of width to height, and the complexity of the tooth roots hidden inside the jaw. The team couldn’t tell which of the three recognised species of Paranthropus the bones belong to, but based on the location it is likely to be Paranthropus aethiopicus or Paranthropus boisei.

The jawbone is about 2.6 million years old, the team says, based on multiple dating methods. That makes it one of the oldest Paranthropus known.

“There’s no question that it’s Paranthropus,” says Carrie Mongle at Stony Brook University, New York, who wasn’t involved in the research. “I don’t think there’s any question about the date.”

The fragments of the Paranthropus mandible after being assembled in the field

Alemseged Research Group/University of Chicago

Previously, the northernmost Paranthropus specimen was a skull from Konso in southern Ethiopia. The new specimen is over 1000 kilometres further north.

“The main point is that it expands the geographic range of Paranthropus,” says Mongle.

For Alemseged, the new specimen is also evidence of greater versatility. Paranthropus’s large jaws and teeth have long been interpreted as evidence of a tough, chewy diet. While we don’t yet know what the Mille-Logya Paranthropus ate, the area seems to have been relatively open, whereas other early specimens of Paranthropus were found in wooded areas.

“Yes, they were specialised,” says Alemseged, “[but] I think we might have inflated our understanding of that specialisation.” Their specialised bodies don’t seem to have stopped them living in both wooded and grassy areas. “Different Paranthropus populations were able to exploit different habitats based on where they lived, like Homo did, like Australopithecus did.”

Mongle says there was already evidence of Paranthropus succeeding in new environments, because they adapted to the expansion of grasslands across east Africa, opting to eat more grasses. The new Mille-Logya specimen adds to the evidence of their versatility.

In recent years, evidence has emerged that Paranthropus could use, and perhaps also make, simple stone tools. For instance, stone tools described in 2023 from Kenya were found associated with Paranthropus teeth and no other hominin remains. In 2025, Mongle helped describe the first Paranthropus hand, which proved to be highly dextrous.

That makes sense, says Alemseged, because there is growing evidence that Australopithecus could make and use tools, and they existed before Paranthropus. Tool use may well go back to the ancestor we share with chimpanzees, he says.

Journal reference:

Nature DOI: 10.1038/s41586-025-09826-x

Discovery Tours: Archaeology and palaeontology

New Scientist regularly reports on the many amazing sites worldwide, that have changed the way we think about the dawn of species and civilisations. Why not visit them yourself?

Find out more

HUMANS | JAN 21, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

Oldest known rock art is a 68,000-year-old hand stencil with claws

Newly discovered rock art sites in Sulawesi, Indonesia, that date to nearly 68,000 years ago are thought to be the oldest rock art in the world, pre-dating Neanderthal hand stencils in Spain by 1100 years

By James Woodford

This hand stencil appears to have been modified to appear more claw-like

Ahdi Agus Oktaviana

A nearly 68,000-year-old hand stencil found on the wall of a cave in Sulawesi, Indonesia, may be the oldest rock art ever discovered – and rather than a simple handprint, it appears to have been touched up by the artist, possibly to make the fingers look claw-like.

In recent decades it has become apparent that Sulawesi is a key location in the human story – home to numerous species of hominins from as long ago as 1.4 million years when an early human species, likely Homo erectus, made the first known sea voyages.

In 2024, Maxime Aubert at Griffith University, Gold Coast, Australia, and his colleagues reported that they had found the world’s oldest known “representational” art on the island – a pig depicted alongside human-like figures, that was at least 51,200 years old. Now, his team have announced the discovery of a further 44 rock art sites in south-eastern Sulawesi, and dated one partial hand stencil at a site called Liang Metanduno, on Muna Island, east Sulawesi, to 67,800 years ago.

Previously, the world’s oldest known rock art was a hand stencil at a Neanderthal site in northern Spain, dated to a minimum age of 66,700 years old – 1100 years younger than the new Sulawesi site.

The Sulawesi stencil shows signs of modification, says Aubert, as the tip of one finger appears to have been artificially narrowed. This was done either through the application of extra pigment or by moving the hand during pigment application, which is a type of hand stencil art so far known only in Sulawesi.

“It’s more than just a stencil of a hand,” says Aubert. “They are retouching it. We don’t know if they’re doing this by retouching it with a paintbrush or maybe if you spray it, and then as you do it, you move your hand, you can have the same effect.”

He says no one knows why they are using this method, “but it seems to me they want to make it look more like it’s an animal hand, possibly with claws.”

The team also identified animal figures inside a cave in Sulawesi, Indonesia

Maxime Aubert

Aubert says it is impossible to know what species made the hand stencil, but based on the extra artistic intention of narrowing the fingers, it was most likely a modern human, implying that these people were close ancestors of the first humans to reach Australia.

There is evidence from a site called Madjedbebe in Arnhem Land, Australia, that Homo sapiens reached the continent at least 60,000 years ago. Evidence is also mounting that Sulawesi is one of the most important and earliest stepping stones between South-East Asia to New Guinea and onto the Australian continent.

“The implications of these discoveries go beyond just the history of the art,” says Aubert. “The people who made that art are probably the ancestors of the first Australians and now we know their ancestors were making rock art in Sulawesi at least 68,000 years ago.”

Team member Adam Brumm, also at Griffith University, says the Spanish Neanderthal hand stencil and the Sulawesi rock art were made essentially in the same way – someone spraying ochre over their hand.

A close-up of some of the rock art

Maxime Aubert

“But then the modern human did something different,” says Brumm. “They deliberately altered the outlined fingers of the stencil to artificially narrow the digits and make the tips more ‘pointy’, thus transforming this human hand mark into something else, perhaps a representation of an animal claw.

“This indicates a playfulness on the part of the modern human artist; altering an otherwise ‘ordinary’ hand stencil in this manner is a sign of creative imagination and abstract thinking that is not evident in the human hand mark left behind by the Neanderthal.”

Martin Porr at the University of Western Australia in Perth says the new find is the world’s oldest known rock art that can be attributed to our species. “I agree that the dates for the stencils are, in fact, in agreement with other current dates for the earliest presence of Homo sapiens in the region, both in Australia as well as mainland Asia and South-East Asia,” says Porr. However, he thinks much more work is needed before it can be confidently concluded which routes humans took to reach Australia.

Journal reference:

Nature DOI: 10.1038/s41586-025-09968-y

Ancient caves, human origins: Northern Spain

Discover some of the world’s oldest known cave paintings in this idyllic part of Northern Spain. Travel back 40,000 years to explore how our ancestors lived, played and worked. From ancient Paleolithic art to awe-inspiring geological formations, each cave tells a unique story that transcends time.

Find out more

Life

- How – and why – we chose the best 21 ideas of the 21st century: 2026 Jan 21

- A fascinating book reveals the ancient story of horses and humans (paid): 2026 Jan 21

- Piercing crocodile close-up wins ecology photo competition: 2026 Jan 22

- Our earliest vertebrate ancestors may have had four eyes (paid): 2026 Jan 21

- Bird retinas work without oxygen, and now scientists know how: 2026 Jan 21

- Octopuses prompt rethink of why animals evolve big brains (paid): 2026 Jan 21

- Bubble feeding trick spreads through humpback whale social groups: 2026 Jan 21

LEADER: LIFE | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

How – and why – we chose the best 21 ideas of the 21st century

From smartphones to net zero, there has been no shortage of innovative ideas in the past 25 years, which is why we have taken a look back to choose the best

By New Scientist

gualtiero boffi/Alamy

What separates a good idea from a bad one? It isn’t always easy to tell. Take the invention of vaccination, for example. Drawing pus from a woman infected with cowpox and injecting it into an 8-year-old boy seems utterly reckless, but in doing so, 18th-century physician Edward Jenner found a way to fight the deadly scourge of smallpox.

It is only with hindsight that we can see Jenner was on to something: a principle that has now saved millions of lives. That is why, a quarter of the way into this century, we have decided to look back and celebrate the ideas that have really mattered in the past 25 years – the ones that are already transforming the way we behave, think or understand what’s around us.

In coming up with our list of the 21 best ideas of the 21st century, there was plenty of heated debate within the editorial team. Our first hurdle was the unexpectedly puzzling question of whether the first quarter of the 21st century concluded at the start of 2025 or the end of it. To be safe, we chose the end. Then it was onto the ideas themselves and further discussion of what should really count, from whether the microbiome is actually a 21st-century concept (we decided it is,) to whether social media was a good or a bad idea (after some back and forth, we decided on bad. What makes a good or a bad idea is, after all, subjective.

In the end, we devised a rigorous set of criteria. To make the list, a concept must have already had a transformative impact – whether on our understanding of ourselves, our health or the wider universe. It must have an idea at the heart of it, even if it was backed up by scientific discoveries. And finally, it must have happened in the past 25 years.

“ Rather than trying to forecast the future, it is worth taking the time to reflect on the past “

You might think that last criterion would be easy to administer, but there were lots of suggestions that didn’t quite make it. Gravitational waves were discovered in the 21st century, bringing us a whole new way of viewing the cosmos, but they were first predicted by Albert Einstein 100 years earlier. Other ideas like weight-loss drugs, personalised medicine and mRNA vaccines hold much promise, but haven’t quite had their time to shine yet. Perhaps they’ll make it into our 2050 list.

In coming up with our picks, we couldn’t ignore the many ideas that sounded great at first, but turned into flops. That’s why we have also compiled a list of the five worst ideas of the century so far. Sometimes, the line between best and worst is surprisingly hard to draw, which is why a few of our choices on the best list might seem controversial – like smartphones, for instance, which many people would rather see removed from the planet, but on balance we see as a positive. Or the 1.5°C global warming target, which could be seen as a failure: a new report has found that the three-year average of global temperatures has just passed 1.5°C for the first time. Despite this, we argue that changing the threshold down from 2°C remains one of the century’s best ideas, setting the benchmark for global climate ambitions.

Getting on with actually transitioning away from fossil fuels is certainly a good idea, and one perhaps surprising hero we have recognised in this area is Elon Musk. In 2016, before he began dabbling in social media and politics, Musk’s car company Tesla opened its first “gigafactory” in Nevada, marking a turning point in the energy transition by using economies of scale to electrify our transport and energy systems. Other attempts to battle climate change, like alternative fuels and carbon offsets, have made our naughty list for doing more harm than good.

One thing we learned in putting our selection together is the extent to which ideas come about by chance. For most of us, finding a working plug socket on a long train journey enables little more than a few extra minutes of smartphone scrolling. But for two physicists back in 2005, it changed the world’s entire decarbonisation strategy. Similarly, it was a eureka discovery that revealed the origins of our most complex thought processes. We learned that brain regions don’t work alone, but coordinate amongst themselves, creating a powerful and complex web. Since then, these neural networks have transformed our understanding of the brain, as well as how we diagnose and treat its problems.

Looking back a quarter of a century, we find that the world was a very different place. We had avoided the millennium bug, the first draft of the human genome had just been completed and the first crew had arrived at the International Space Station. We didn’t know what a Denisovan was and the word “microbiome” wasn’t in our vocabulary. In the pages of New Scientist, we were celebrating new technologies like wireless communication, marvelling at the computer chip no bigger than an aspirin tablet that would let it happen. “Its heart is a device called a Bluetooth chip,” we wrote, “and pundits are tipping it as The Next Big Thing”. A reasonable guess, but headphones that you don’t have to plug in are more of a nice-to-have than a world-changer, so we called that one wrong.

This reflects the fact that while predictions can be appealing, they are all too often wrong and left forgotten in our hurry to move on to the next shiny thing. Rather than trying to forecast the future, this exercise has taught us that it is worth taking the time to reflect on the past. Advances in health, technology and environmentalism have undoubtedly made the world a better place this century, and let us hope – if not predict – that they will continue to do so.

LIFE | JAN 21, 2026, 1:00 PM EST | VIEW ON NEW SCIENTIST

A fascinating book reveals the ancient story of horses and humans

Ludovic Orlando's Horses is an enthralling account by one of the main players, detailing how genetics has rewritten what we know about the intertwined story of horses and humans, now spanning over 4000 years

By Christa Lesté-Lasserre

Arabian horses race in the Liwa International Festival, Abu Dhabi

KARIM SAHIB/AFP via Getty Images

Horses

Ludovic Orlando (translated by Teresa Lavender Fagan), Princeton University Press

It is in the epilogue of his latest book that equine geneticist Ludovic Orlando delivers one of his biggest take-home messages: “[T]he horse,” he writes, “remains what it has been for almost our entire history, a vector for bringing people together.”

It is both a beautiful statement and a major theme in Horses: A 4000-year genetic journey across the world. In this translation from the French, we see how human civilisation evolved alongside the domesticated horse. With Orlando, we follow a scientific journey that explains the mysteries of this impressive, influential animal across its 4200 years beside humans.

But the statement in reverse – as Orlando’s text reveals – is true as well: humans, across history, have also brought horses together.

When our ancestors first fenced in, milked, harnessed, drove and eventually rode horses more than four millennia ago, they became unwitting masters of genetics, mixing and matching individuals in ways that would produce chariot horses, racehorses, desert endurance horses, plough horses, war mounts and today’s leisure-riding ponies. We know this not only from the hundreds of specialised breeds alive today, but, more deeply, through their DNA.

That’s where Orlando’s brilliance shines. Over the past decade, his sequencing work has overturned so much of what the world thought it knew about horses: domestication, where it happened and how horses evolved afterwards – and even how horse lineages stretched back tens of millions of years. This is all told with vivid detail and captivating storytelling, built on mysteries teased apart through unravelled double helixes.

I interviewed Orlando nearly 13 years ago, early in his career, just after he and his colleagues had sequenced the DNA from a 700,000-year-old fossilised horse bone found in Thistle Creek in the Canadian Yukon – then the oldest fully sequenced genome of any organism. At the time, Orlando was driven by the age of the specimen, not its species. Neither of us knew that he would become a leading authority on the horse genome.

“ Orlando’s sequencing work has overturned so much of what the world thought it knew about horses “

Now, in this book, we follow him as he traces clues across millennia, cultures and continents in search of the true history of humanity’s other best friend. Ancient DNA from bones and hair forms the foundation, but he fits the findings into broader frameworks from archaeology, ancient art, historical texts, even linguistics – tracking when and where horse-related words emerged.

Each chapter opens with rich anecdotes that spill into enthralling myth-busting. Medieval warhorses weren’t the giants we imagined. Mustangs racing across the Western plains of the US aren’t native to North America, but are descendants of horses brought from Europe after the 15th century. Przewalski’s horses aren’t truly wild, but are descendants of an early, abandoned domestication attempt. And those spectacular Arabian horses – think elegant white steeds in Bedouin tents – aren’t the foundation of all fine riding horses worldwide.

In fact – spoiler alert – save for the Przewalski, every horse today comes from a single domestication event 4200 years ago in what is now south-west Russia, as Orlando’s comparisons of ancient and modern genomes reveal.

In page after page, he shows us the limitations of what we thought we knew – and how genomic sequencing has added nuance to that picture. Readers meet communities on the Asian steppes and Indigenous people in the US, and study artefacts alongside scientists, in the service of understanding how horse and human came together – and how that reshaped the world.

While it’s a wild ride, horse-savvy readers may stumble over small slips in language – such as describing ancient DNA linked to spotted horses as “dappling” or calling Thoroughbreds racing in Kentucky or Melbourne “English”.

Still, Horses is a thundering read, reminding us that the long, tangled history of humans and horses isn’t just written in bones and genomes, but also in the enduring ways we continue to shape one another.

Christa Lesté-Lasserre is a science journalist specialising in animal health and behaviour based in Greater Paris

LIFE | JAN 21, 2026, 7:01 PM EST | VIEW ON NEW SCIENTIST

Piercing crocodile close-up wins ecology photo competition

A striking shot of biting flies on the head of a crocodile is among the winning entries in the British Ecological Society’s annual Capturing Ecology photography competition

By Sam Wong

Biting flies on the head of an American crocodile

Zeke Rowe/British Ecological Society

Most animals would be afraid to go near a crocodile, but biting flies have no qualms about landing on this fearsome predator and drinking its blood. This photo, taken by Zeke Rowe in Panama’s Coiba National Park, was chosen as the overall winner of the British Ecological Society’s annual Capturing Ecology photography competition.

“This crocodile was lurking in a tidal marsh off the beach,” said Rowe, a PhD candidate at Vrije Universiteit Amsterdam in the Netherlands, in a statement. “I got as close and low as I dared, waiting for that direct eye contact.”

Cape sparrows and other birds disturbed by a lioness

Willem Kruger/British Ecological Society

The judges also selected 10 category winners, including this shot by Willem Kruger, a South African-based photographer, which won in the interactions category. During the dry season in Kgalagadi Transfrontier Park on the border between South Africa and Botswana, flocks of birds were drinking at a waterhole when a pride of lions approached, scaring the birds away.

Wallace’s flying frog

Jamal Kabir/British Ecological Society

Jamal Kabir at the University of Nottingham, UK, won in the animals category with this image of a Wallace’s flying frog (Rhacophorus nigropalmatus). These amphibians, named for the biologist Alfred Russel Wallace, use their webbed feet to glide between trees in the rainforests of South-East Asia.

A bighorn sheep has its nosed swabbed

Peter Hudson/British Ecological Society

A bighorn sheep (Ovis canadensis) in the Rocky mountains has its nose swabbed in this photo by Peter Hudson, a photographer and biologist at Penn State University, which was highly commended in the ecologists in action category. Pneumonia is a major issue for bighorn herds, often wiping out young lambs in the spring. Researchers suspected that asymptomatic adults were spreading the disease to vulnerable youngsters, so they implemented a campaign to test wild sheep and treat the infected individuals. This helped to reduce mortality and let populations recover.

Fly on mushroom

Francisco Gamboa/British Ecological Society

In the mountainous Altos de Cantillana nature reserve in Chile, wildlife photographer Francisco Gamboa captured this photo of a fly resting on a mushroom, which won in the plants and fungi category.

Intertidal education

Liam Brennan/British Ecological Society

In another highly commended image from the ecologists in action category, taken by wildlife researcher and photographer Liam Brennan, three undergraduate students are using a beach seine – a type of fishing net – to count coastal fish species in New Brunswick, Canada, as part of a project monitoring seasonal population changes.

Insect and ecosystems expedition safari: Sri Lanka

Journey into the richly biodiverse heart of Sri Lanka on this unique entomology and ecosystems-focused expedition.

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LIFE | JAN 21, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

Our earliest vertebrate ancestors may have had four eyes

Extraordinary fossils of 518-million-year-old jawless fish, among the earliest known vertebrates, appear to show that these animals had two pairs of eyes

By James Woodford

Illustration of Haikouichthys, a fish from the Cambrian period, with a second pair of eyes suggested by fossil evidence

Xiangtong Lei, Sihang Zhang

Over half a billion years ago, the world’s oldest known vertebrates seem to have sported an extra set of eyes – and humans may still carry a remnant of this ancient evolutionary innovation.

Extraordinary fossils of two species of jawless fish called myllokunmingids were found by Peiyun Cong at Yunnan University in China and his colleagues between 2019 and 2024, on the banks of Dianchi Lake in south-west China.

The ancient life forms found in this area, known as the Chengjiang biota, are preserved in exquisite detail. They date from around 518 million years ago, during a period known as the Cambrian, when life exploded in diversity, creating most of the major animal groups alive today.

Importantly, the vertebrate fossils found by Cong’s team included preserved soft body parts and the creatures’ eyes.

Complex eyes evolved independently in several groups of animals. Some invertebrates, such as insects, have compound eyes made up of hundreds or thousands of separate units, each with its own lens, cone and light receptors, together creating a mosaic image.

Vertebrates, such as humans and reptiles, have what scientists describe as camera-type eyes. Our eyes consist of a spherical lens, a retina, an iris and muscles that control their movement. They also contain pigmented structures called melanosomes, which among other things determine our eye colour.

Light is focused on the retina, creating signals that are transmitted to the brain through the optic nerve.

When Cong and his colleagues studied the fossils under an electron microscope, they could see a pair of eyes on the side of the head with preserved melanin-containing melanosomes, as well as two mysterious, much smaller, black smudges in between.

“More strikingly, there is also an impression of a lens in each of the lateral eyes and centrally-positioned eyes,” says team member Jakob Vinther at the University of Bristol in the UK.

Similar dark spots have been seen in myllokunmingid fossils before, but they have been interpreted as nasal sacs or other organs. Vinther says his team’s evidence suggests that these animals had two pairs of camera-type eyes. “This would have enabled these 518-million-year-old vertebrates to form an image of their world much like we do,” he says. “But a key difference is that they used four eyes and not just two.”

A fossil of Haikouichthys showing the preserved melanosomes

Xiangtong Lei, Sihang Zhang

The team believes that this ancient, extra pair of eyes went on to evolve into a set of organs known as the pineal complex. Some vertebrates such as reptiles still have a light-sensitive organ at the top of the head called the parietal eye, but in mammals, the complex consists of only the pineal gland, which regulates our sleep cycle by secreting melatonin.

“We show [the pineal organs] had a more important function as eyes in the early vertebrates and could create somewhat of a decent image before they evolved into organs regulating our sleep cycle,” says Vinther.

The big eyes were probably better for seeing things in high resolution, he says, while the smaller eyes would have helped the animal to spot objects approaching it. This would have provided a slightly different field of view, important in Cambrian seas where these jawless fish would have been a desirable meal.

“They likely could see objects quite well, telling their shape and some degree of three-dimensionality,” says Vinther. “They likely also had a broad view of their surroundings, sort of IMAX-style, thanks to their four eyes.”

Tetsuto Miyashita at the Canadian Museum of Nature in Ottawa says he is “half believing and half recoiling from this new, fascinatingly original interpretation” of these fossils.

The structures visible between the lateral eyes of these fossils have long puzzled researchers and it is a “light bulb” moment to realise they may be another set of camera eyes, he says.

But if they are eyes, that would raise the question: where is the nose? “So much about early fish evolution revolves around the nose, so not having one preserved is unlikely from a developmental standpoint,” he says.

Miyashita predicts there will be substantial debate until experts can see “eye to eye”. “Does it really make so much sense to have so many prominent eyes on the head?” he says.

John Paterson at the University of New England in Armidale, Australia, says it makes sense that these prey species “developed that type of vision, just to avoid scary predators coming after them”.

“The Cambrian is a bit of a weird time when you see animals doing strange things for the first time in an evolutionary sense, where it’s not just always a pair of eyes looking to the side or looking forward – but you can actually have eyes on other parts of the head.”

Karma Nanglu at the University of California Riverside says he would like to see detailed mapping of the entire body of the fossils to see whether there are any other similar markings elsewhere, which may indicate that the second set of eyes is in fact just an artefact of the chemistry of fossilisation.

Journal reference:

Nature DOI: 10.1038/s41586-025-09966-0

Dinosaur hunting in the Gobi desert, Mongolia

Embark on an exhilarating and one-of-a-kind expedition to uncover dinosaur remains in the vast wilderness of the Gobi desert, one of the world’s most famous palaeontological hotspots.

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LIFE | JAN 21, 2026, 11:00 AM EST | VIEW ON NEW SCIENTIST

Bird retinas work without oxygen, and now scientists know how

The light-sensitive tissue of birds’ eyes is not supplied with oxygen by blood vessels – instead, it powers itself with a flood of sugar, and this may have evolutionary benefits

By Jake Buehler

Researchers studied how zebra finches’ eyes work

Ger Bosma/Alamy

A crucial part of birds’ eyes is unlike any tissue known in vertebrate animals. Their retina – the light-sensitive layer at the back of the eye – sidesteps the near-universal need for oxygen by vacuuming up heaps of energy-rich sugar instead.

The discovery solves a 400-year-old mystery about the physiology of birds’ eyes. It is also a neurobiological paradigm shift, says Christian Damsgaard at Aarhus University in Denmark.

“We have the first evidence that some neurons can work without any oxygen, and they’re found in the birds that fly around in our gardens,” he says.

Retinas detect light and relay this information as nerve signals to the brain. The tissues require a lot of energy and are sustained by oxygen and nutrients coursing through a mesh of blood vessels. But bird retinas are extremely thick, and no vessels weave into the tissue. It was a mystery how their retinas received enough oxygen to keep the deep stacks of important nerve cells alive.

Damsgaard and his colleagues studied zebra finches (Taeniopygia guttata) in the lab to find an answer. The team put tiny oxygen sensors in the finches’ eyes and found that the inner layers of the retina weren’t getting oxygen at all.

“They get oxygen from the back of the eye, but it cannot diffuse all the way through the retina,” says Damsgaard.

The team measured the activity of metabolic genes in different parts of the retina. This showed that the oxygen-free areas were heavily using glycolysis, a process that can break down sugars without oxygen. However, it is a much less efficient option.

“You need 15 times more glucose to generate the same amount of energy,” says Damsgaard. So, how was the retina getting that much sugar?

Enter the pecten oculi, a rake-shaped collection of blood vessels found in birds’ eyes. The pecten was discovered centuries ago, and researchers had speculated that it piped in oxygen. But the team’s readings ruled that out. Instead, they discovered the pecten was practically soaking the retina in glucose – four times more than what brain cells suck up – to fuel its ravenous glycolysis engine.

Luke Tyrrell at the State University of New York at Plattsburgh is surprised that birds would evolve to rely on such an inefficient process for their vision. “The retina – especially a bird retina – is one of the most energy-needy tissues in all of the animal kingdom,” he says.

The thick, blood vessel-free retinas may have adapted to enhance birds’ visual acuity, making the pecten sugar pump worth the evolutionary hassle. The oxygen-free retina may have also set the stage for some birds to evolve high-altitude migration flights, with their vision unaffected by low oxygen levels.

For Pavel Němec at Charles University in Prague, Czech Republic, the findings are a “clear case that reminds us that evolution brings very counterintuitive solutions” to physical hurdles.

Damsgaard and his team wonder if human cells could eventually be modified to be more tolerant of harmful oxygen-free conditions, such as in the aftermath of a stroke.

Journal reference:

Nature DOI: 10.1038/s41586-025-09978-w

LIFE | JAN 21, 2026, 5:00 AM EST | VIEW ON NEW SCIENTIST

Octopuses prompt rethink of why animals evolve big brains

A popular idea suggests a link between big brains and a rich social life, but octopuses don't fit the pattern, which suggests something else is going on

By Chris Simms

Octopuses that live in shallow water – like the common octopus – typically have big brains

Shutterstock

Octopuses may have big brains because of environmental – not social – factors.

Large brains in mammals are generally thought to be linked to social behaviour, an idea known as the social brain hypothesis. The more social connections that members of a species have, the bigger the brain needs to be to manage those connections, a pattern that holds for groups including primates, dolphins and members of the camel family.

But there are animals like cephalopods – octopuses, squid, cuttlefish and nautiluses – that have relatively large brains, show signs of intelligent behaviour and yet live largely solitary lives, with little in the way of parental care, complex group dynamics or social learning.

To investigate what might be behind these larger brains, Michael Muthukrishna at the London School of Economics and his colleagues have brought together data on 79 species of cephalopods for which brain information is available. They took brain size to be the total volume of the animals’ central nervous system. This was necessary because an octopus, for example, has nine brains, not merely one: a central one in the head that controls the nervous system, and a smaller, semi-independent brain in each of its eight limbs.

“What could be more different from humans than this kind of alien species on our planet, with its wacky multi-appendage brain with arms?” says Muthukrishna.

The data the team gathered showed no link between brain size and sociality, but did reveal that cephalopods generally have larger brains when they live in shallower and seafloor habitats, which have a greater range of things with which to interact, or objects to manipulate or even use as tools, and are richer in calories. Species that float in the featureless deep sea tend to have smaller brains.

“That relationship is quite robust,” says Muthukrishna. “But this is a cautious finding,” because there is brain data available for only about 10 per cent of the 800 species of cephalopod that live today.

“It’s interesting that there’s no social brain effect in octopuses, but it is not surprising,” says Robin Dunbar at the University of Oxford, who proposed the social brain hypothesis some 30 years ago. As octopuses don’t live in coherent social groups, their brains don’t need to do the additional work that entails, he says.

Paul Katz at the University of Massachusetts Amherst says it is certainly possible that every time cephalopods evolved to live in deeper waters, their brain size reduced. “It’s like every time you see animal species that get stuck on islands, they get smaller. There’s an island phenomenon, so there could be a deep-sea phenomenon, too,” he says, but he adds that it could just be correlation.

Muthukrishna previously published a study of whales and dolphins, suggesting that brain size predicts the breadth of their social and cultural behaviours, as well as ecological factors like the diversity of prey. The fact that cephalopods, which diverged from vertebrates over 500 million years ago, display a similar pattern – which he has also modelled in humans – is evidence for an idea called the cultural brain hypothesis, developed by Muthukrishna and his colleagues, which describes how information and ecological selection pressures can also produce large, complex brains, he says.

“Big brains aren’t just down to sociality,” says Muthukrishna.

“I totally agree that the explanations for why humans have big brains are based on what we know about humans, so if you want to really understand the evolution of large brains, you should study distantly related species,” says Katz. But it is difficult to look at the behaviour of current species and make a statement about what was going on 500 million years ago, when cephalopod brains would have evolved in a very different sort of predator-prey environment before fish were widespread, he says.

Moreover, other evidence has indicated that cephalopod brains grew larger as a result of competition with fish, says Katz.

Dunbar says octopuses may generally need a lot of brain power because they have eight arms that they can use independently. “It’s a bit unclear what an octopus brain is, because it kind of has a bit of a brain in each arm, but a lot of what the brain does is manage the body and keep it doing what it needs to do to stay alive,” he says.

Bigger brains evolving where more calories can be found does make sense, though, says Dunbar. “You can’t increase the size of your brain unless you solve the energy problem. Once you’ve got the big brain in place, you can use it for many different things. Which is precisely why humans can read and write and do clever maths when that wasn’t in our evolutionary environment of selection.”

Reference:

bioRxiv DOI: 10.1101/2024.05.01.592020v5

LIFE | JAN 20, 2026, 7:01 PM EST | VIEW ON NEW SCIENTIST

Bubble feeding trick spreads through humpback whale social groups

Humpback whales off the west coast of Canada have learned a cooperative hunting technique from whales migrating into the area, and this cultural knowledge may help the population cope as food becomes scarce

By Alessio Cozzolino

Humpback whales work together to trap fish by surrounding them with bubbles

Jenn Dickie/North Coast Cetatean society

An innovative feeding behaviour has spread rapidly through humpback whales in the fjords of western Canada, in a clear example of how cultural knowledge can help animal populations to survive.

Bubble-net feeding is a group hunting technique in which whales blow bubbles to corral fish, then surge upwards together to gulp them down.

“It’s an activity that’s done cooperatively, given the level of coordination and division of labour involved,” says Ellen Garland at the University of St Andrews, UK.

The behaviour has been documented for decades among humpbacks (Megaptera novaeangliae) in Alaskan waters, and researchers have started seeing it recently in the northeastern Pacific population off Canada.

But it is tricky for researchers to establish whether complex behaviours like this are transmitted through social learning — rather than being independently discovered by multiple individuals.

To tease apart the process, Éadin O’Mahony at the University of St Andrews and her colleagues analysed field observation data from 2004 to 2023, focusing on 526 individuals living in the Kitimat Fjord System in British Columbia, within Gitga’at First Nation territory.

The team identified the whales using images of their tail flukes, which are unique to each animal. The data shows that 254 individuals performed bubble-net feeding at least once, and about 90 per cent of these events occurred in a cooperative context.

The behaviour also appeared to take off after 2014, coinciding with a major marine heatwave in the north-east Pacific that reduced prey availability.

“With the heatwave, as prey availability went down, a whale’s ability to change feeding behaviour would help it maintain its daily calorie intake,” says O’Mahony.

Whales were more likely to adopt bubble-net feeding if they regularly associated with others that already used the technique. Bubble-net feeding was probably introduced in the region by whales migrating from elsewhere in the north-east Pacific, but the pattern points mainly to the behaviour spreading through local social networks, carried by stable groups and influential individuals.

“What we see from the heatwave years onward is an increase in whales already in the area who previously didn’t take part in bubble-net feeding,” says O’Mahony.

Humpback whales’ ability to pass on knowledge through social groups may be vital to their survival, and understanding their culture could help us protect them, the researchers say.

“It’s not just about how many animals are left, but about whether the social behaviours that make the population function are coming back too,” says Ted Cheeseman, co-founder of the citizen science platform Happywhale, who wasn’t involved in the study.

Journal reference:

Proceedings of the Royal Society B DOI: 10.1098/rspb.2025.2409

Arctic expedition cruise with Dr Russell Arnott: Svalbard, Norway

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COLUMNIST HEALTH | JAN 23, 2026, 5:00 AM EST | VIEW ON NEW SCIENTIST

Why biological clocks get our 'true age' wrong – and how AI could help

Your chronological age can’t always tell you the state of your health, which is why biological clocks have been developed to show our risk of developing diseases or dying – but they’re not all they are cracked up to be, says columnist Graham Lawton

By Graham Lawton

You may be chronologically older than your “true age”

REUTERS/Toru Hanai

When I first started writing about ageing years ago, there was a buzz around something called biological clocks, also known as ageing clocks or “true age” measurements. In principle, these are quite simple: we all have a chronological age, the number of years since birth, but this doesn’t necessarily reflect how far we are down the slippery slope from birth to decrepitude.

On average, this follows a fairly predictable trajectory, with gradual declines in almost every physical and mental attribute throughout adulthood. When we judge how old somebody is, we are intuitively totting up many of these tell-tale signs we see – the wrinkles and grey hair, or changes in posture, gait, voice, mental acuity and so on.

The goal of measuring biological age is to capture this decline in a single metric, evaluated scientifically and expressed in years. The results tell us something we intuitively know: some people age better than others.

Most people are, biologically, within a few years either side of their chronological age. But the two can diverge wildly. A 56-year-old (which I am) can have the biological age of a typical 30-something (which I almost certainly don’t), while another can have the biology of a septuagenarian (ditto). Crucially, biological age can rise more slowly than chronological age and even go down.

Biological age is a useful measure. It can give individuals succinct and easy-to-understand information about their overall state of health, encourage them to make lifestyle changes and tell them whether any resulting interventions, such as diet and exercise, are working. Judging from the number of commercial companies offering biological age testing, there is substantial clamour for such information, even though it is costly.

For scientists trialling anti-ageing interventions, it is a useful tool to see what works and what doesn’t without having to wait years to observe whether their guinea pigs (human or otherwise) decline and die at different rates. And for those working on the basic biology of ageing, biological age measurements can help them understand what is going on in our bodies as we get older.

So, what’s not to like? Quite a lot, as it happens. Biological age is sound in principle, but in practice leaves a lot to be desired.

The first biological clocks were based on epigenetic markers. These are molecular tags added to or removed from nuclear DNA that influence patterns of gene expression. About a decade ago, researchers led by Steve Horvath – the father of biological clocks, based at the University of California, Los Angeles – found that while there is a lot of individual variation, epigenetic markers change predictably over an average lifespan. Measure the right ones, feed the data through a complex algorithm and, hey presto, out pops an estimate of somebody’s biological age.

But epigenetics isn’t the only way to make an estimate. In the intervening years, many other clocks have been developed based on various other biological markers, including blood proteins, the length of caps of DNA at the ends of chromosomes called telomeres, urine metabolites, facial images and chest X-rays. That wouldn’t be a problem if they all came up with roughly the same answer, but they don’t.

As just one example, we can see this in a recent analysis of a clinical trial in humans called CALERIE, which examined the impact of long-term caloric restriction – a proven anti-ageing intervention in many organisms, though whether it applies to us remains up in the air. The CALERIE trial applied five different ageing clocks to 220 adults. Two of the clocks showed a significant reduction in biological age among the calorie-restricted participants. Three of them didn’t. Which should we believe? This is a problem that bedevils anyone – whether an individual or a scientist – who uses an ageing clock.

Another problem with ageing clocks is the illusion of accuracy. Most spit out a single figure with no error bars, despite inherent levels of uncertainty in the data and the analyses. According to a recent paper in the journal npj Aging, that is just the tip of the iceberg. Overall, the researchers conclude, existing clocks don’t do what they say on the tin and they run the risk of giving people either unwarranted confidence or unnecessary anxiety about the state of their health.

Does that mean that ageing clocks are useless? Not entirely. The paper’s authors, led by Dmitrii Kriukov at the Skolkovo Institute of Science and Technology in Russia, say that “all limitations of aging clocks are hypothetically solvable”. But whether they are worth solving is another question.

In part, that is because of a new and highly promising approach coming down the pipeline. Existing ageing clocks need biological samples. The new approach doesn’t, relying instead on – you guessed it – artificial intelligence, specifically something called large health models (LHMs). These are essentially large language models – like those that power AI chatbots such as ChatGPT – trained on huge volumes of health data to predict two of the main goals of ageing clocks: an individual’s risk of dying and their risk of developing age-related diseases. A recent paper in Nature Medicine reported that this approach outperforms existing clocks.

LHMs are still in development, and while we’re still getting them up to speed, the problems with existing clocks may be solved. But the take-home message is this: if you’re tempted to have your biological age measured, think twice. Or, if you have done so already, take the results with a pinch of salt. In return, I promise that next time I’m writing a story on ageing, I’ll be much more sceptical about research that uses them. Older, wiser.

HEALTH | JAN 22, 2026, 5:00 AM EST | VIEW ON NEW SCIENTIST

Strips of dried placenta help wounds heal with less scarring

Donated placentas can be processed into thin, sterilised sheets that are packed with natural healing substances and reduce scarring when applied to wounds

By Alice Klein

A scanning electron micrograph of a section through a human placenta

Science Photo Library

Skin wounds heal with less scarring when thin sheets of dried human placenta are applied as dressings, according to research in mice and people.

The placenta’s healing properties have been known since at least the early 1900s, when the tissue was sometimes applied to burns to reduce scarring. However, the treatment fell out of favour due to the potential risk of disease transmission.

Now, with new ways to safely sterilise and preserve placentas, such dressings are once again gaining attention. In particular, researchers have been investigating the healing properties of the amniotic membrane, the innermost layer of the placenta that faces the fetus during pregnancy and contains a rich variety of growth factors and immune-modulating proteins.

Several US companies have started harvesting amniotic membranes from placentas donated after planned Caesarean sections. They peel this thin membrane from the rest of the placenta, freeze-dry it, cut it to standard sizes, package it and sterilise it with radiation. This preserves its growth factors and other healing substances, while destroying any pathogens. The resulting tissue paper-like sheets can then be used as wound dressings.

To find out whether these reduce scarring, Geoffrey Gurtner at the University of Arizona and his colleagues made surgical incisions on the backs of anaesthetised mice, and used a device to pull at the sides of the wounds and slow the healing process.

When the wounds were left untreated, they healed poorly, with large, lumpy scars. In contrast, when human amniotic membrane dressings were applied, the wounds healed much better, with thinner, flatter, barely visible scars. The dressings didn’t trigger adverse reactions in the mice due to the placenta having “immune privilege”, a state that prevents attack from the immune system.

Some US surgeons and physicians are already experimenting with using amniotic membrane dressings on people’s wounds, since the Food and Drug Administration permits their clinical use. For example, they are being applied to surgical wounds and chronic, non-healing ones caused by conditions like diabetes.

A study that came out in June 2025 gave us an idea of how well these dressings work in real-life clinical settings. Ryan Cauley at Beth Israel Deaconess Medical Center in Boston and his colleagues combed through a large US-wide database of anonymous patient health records, from which they identified 593 people who had received amniotic membrane dressings to treat chronic wounds or burns and compared them with 593 similar individuals who had been given other treatments.

The researchers found that the wounds treated with amniotic membrane dressings were less likely to become infected and to develop thick, raised scars, known as hypertrophic scars. This validates the growing popularity of these dressings, although Cauley and his colleagues note in their paper that “additional prospective, randomized studies with extended follow-up periods are warranted to validate these findings”.

Meanwhile, other groups are exploring the potential of placental tissue to heal organs other than the skin. For example, in 2023, Hina Chaudhry at the Icahn School of Medicine at Mount Sinai in New York City and her colleagues found that injections of placental cells repaired heart injuries in mice, suggesting they may one day be used to treat damage from heart attacks.

Journal reference:

Plastic and Reconstructive Surgery DOI: 10.1097/PRS.0000000000012746

HEALTH | JAN 21, 2026, 6:30 PM EST | VIEW ON NEW SCIENTIST

Natural ovulation the best option before an IVF frozen embryo transfer

Women using frozen embryos as part of their IVF treatment can either choose to use a medicated cycle or their natural one to prepare their uterus for a pregnancy. Now, scientists have found that the latter option seems to carry fewer risks

By Helen Thomson

Different options exist within IVF treatment, and we’re learning more about their effectiveness

ZEPHYR/SCIENCE PHOTO LIBRARY

Natural ovulation is just as effective as hormone treatment for preparing the uterus for a frozen embryo transfer following in vitro fertilisation (IVF) and carries fewer risks, according to a large, randomised trial.

Emerging evidence suggests that for women who respond well to IVF (by being able to produce lots of eggs), freezing embryos and transferring them in a later cycle may improve success rates. As a result, frozen embryo transfers now account for the majority of embryo transfers globally.

Following IVF, a frozen embryo must be transferred to the uterus at a precise point in the menstrual cycle, when the endometrium – the blood vessel-rich inner lining of the uterus – is thick enough to support implantation.

Women can either choose to use a medicated cycle, where oestrogen and progesterone are taken throughout the month to prepare the uterus, or their natural cycle, if it is regular, which relies on monitoring hormones produced by the body.

Which choice is best has remained somewhat of a mystery, since no previous trial has been large enough to assess complications associated with the different methods.

To address this, Daimin Wei at Shandong University in Jinan, China, and her colleagues conducted a large trial involving 4376 women across 24 fertility centres. All the participants were aged 20 to 40 and were planning to undergo a single frozen embryo transfer. Half were assigned a medicated protocol, the other half used their natural cycle.

“This is the randomised-controlled trial we have been waiting for,” says William Buckett at McGill University in Montreal, Canada, who wasn’t involved in the study.

Live birth rates were similar across both groups at 41.6 per cent for the natural cycle and 40.6 per cent in the medicated group, suggesting that natural ovulation is just as effective as hormone treatment for preparing the uterus for implantation.

Clear differences emerged, however, when maternal complications during and after pregnancy were examined.

Women using their natural cycle had a lower risk of pre-eclampsia, a potentially life-threatening condition characterised by high blood pressure, and experienced fewer early pregnancy losses. They were also less likely to develop placental accreta spectrum, a condition where the placenta fails to detach easily after birth. Rates of Caesarean sections and severe bleeding after birth were also lower in this group.

“These risks not only affect maternal and fetal health during pregnancy, but are also associated with long-term health postpartum,” says Wei.

“This is an important new study,” says Tim Child, chair of the UK’s Human Fertilisation and Embryology Authority’s Scientific and Clinical Advances Advisory Committee. Clinics currently advise people with regular cycles that natural and medicated approaches have the same success rate, he says.

But Child adds that there has been some suggestion that natural cycles result in lower rates of pre-eclampsia. This might be because of the presence of a corpus luteum – a temporary structure in the ovary that forms after ovulation and produces hormones that help prepare the uterus for a pregnancy, which could influence pre-eclampsia risk.

“This very large study confirms and extends previous findings and suspicions, in particular the significantly lower rate of pre-eclampsia, early pregnancy loss, placental accreta, C-section and post-partum haemorrhage [with the natural cycle route],” says Child.

Wei’s team now intends to examine blood samples collected during the trial to identify potential biomarkers that might explain the differences in pregnancy complications.

Journal reference:

The BMJ DOI: 10.1136/bmj-2025-087045

HEALTH | JAN 20, 2026, 6:30 PM EST | VIEW ON NEW SCIENTIST

Cross-training may be the key to a long life

People who combine different types of exercise – such as running, cycling and swimming – seem to live longer than those with less varied workouts

By Michael Le Page

Variety is the spice of life, perhaps particularly when it comes to working out

Lyndon Stratford / Alamy Stock Photo

Many sportspeople do a mixture of exercises to boost their performance. Now there’s evidence that this cross-training could extend their lives, too.

An analysis of two studies that followed people for more than 30 years has found that those who did a variety of activities were 19 per cent less likely to die of any cause during that time than those who were just as physically active but whose exercise was less varied.

“If the total amount of physical activity is kept constant, you will get additional benefits from doing a mix of physical activities,” says Han Han at Harvard University. But studies of this kind can’t establish cause and effect, she says, so the findings are suggestive rather than definitive.

Most exercise studies focus on the intensity or overall amount of physical activity, rather than the variety. Those that have looked at different exercise types tend to compare aerobic with strength exercises.

Han and her colleagues instead looked at nine kinds of mostly aerobic activities: walking; jogging (defined as a pace slower than 6.2 minutes per kilometre); running; cycling outside or on an exercise bike; climbing stairs; swimming laps; rowing or callisthenics (where you use your body weight as resistance, such as squats or pull-ups); tennis, squash or racquetball; and weight or resistance training.

The team got data on the activities of 70,000 women and 41,000 men between 1986 and 2018 from the Nurses’ Health Study and the Health Professionals Follow-Up Study, both done in the US. Study participants were asked to fill in questionnaires every two years detailing their physical activities.

The researchers then looked for associations between people’s activities and their chance of dying from any cause during the study period. People with illnesses that would have affected their ability to exercise were excluded.

The team found that, with all these exercise types, people seemed to reach a point of diminishing returns, in terms of a lower risk of dying during the study period, if they did more than a few hours a week.

This could be why doing a variety of exercises has additional benefits: once someone gets to the point of diminishing returns, they might gain more by spending their time doing a different exercise rather than more of the same, says Han. Another explanation could be that different types of physical activities have distinct physiological effects whose combined benefits are greater.

“We think that future studies could examine the possible synergistic effects of different activities,” says Han. “This will help to identify the optimal mix of activities.” The optimal mix may also change over people’s lifespans, she says.

Few studies have investigated the effect of different types and combinations of exercise on mortality, says Duck-chul Lee at the University of Pittsburgh in Pennsylvania. The findings should be interpreted cautiously because of the limitations of this kind of study, he says. These include the fact that people tend to report doing more exercise than they really do and that people who are healthier overall tend to be more active, which can bias the results.

“However, their findings are also somewhat supported by the current World Health Organization physical activity guidelines suggesting that doing both aerobic and resistance exercise provides a large and more comprehensive health and mortality benefit than doing either alone,” says Lee.

In the future, it should become possible to do this kind of study using data from wearable fitness trackers, rather than relying on self-reporting. “But for now, to get this length of time, you have to rely on the questionnaires,” says Han.

Journal reference:

BMJ Medicine DOI: 10.1136/bmjmed-2025-001513

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Cross-training may be the key to a long life: 2026 Jan 20