Hello Nature readers,
Today we discover a microbiome in a mammoth tooth, consider how to keep Oceania free of bird flu and learn what science says about ultra-processed foods.

A mammoth microbiome

An analysis of the bones and teeth of ancient mammoths (Mammuthus) has revealed some of the microorganisms that called the animals home over one million years ago. Researchers examined ancient microbial DNA from samples of teeth, skulls and skin from 483 mammoths and identified six microbial groups that lived in the mammoths’ mouths and bodies, some of which might have caused disease. DNA from one such group, a family of bacteria called Erysipelothrix, is the oldest host-associated microbial DNA yet discovered at more than one million years old.

Nature | 4 min read
Reference: Cell paper

AI boosts BCI’s grip on robotic arm

A man with partial paralysis was able to operate a robotic arm when he used a non-invasive brain device with a built-in artificial intelligence (AI) ‘co-pilot’. The AI-enabled brain-computer interface (BCI) also allowed the man to perform screen-based tasks four times better than when he used the device on its own. AI co-pilots can make non-invasive BCIs more accurate by shouldering some of the heavy-lifting of decoding brain signals, says AI researcher and study co-author Jonathan Kao.

Nature | 4 min read
Reference: Nature Machine Intelligence paper

The race to defend Oceania against H5N1

So far, Oceania is the only continent to evade H5N1 avian influenza. But researchers say the virus’s arrival is only a matter of time. Particularly vulnerable are New Zealand’s critically endangered bird species, five of which number fewer than 500 individuals. A recent effort using a H5N3 vaccine showed that vaccination can induce a six-month-long immunity in four of these species, which has researchers rushing to develop a strategy to vaccinate greater numbers of animals. But time is ticking; travelling seabirds will begin to arrive in the spring, each with the potential to unleash bird flu on the untouched continent.

The Guardian | 7 min read

The bison are back in town

A study of the last migratory herd of buffalo (Bison bison), which roams the iconic Yellowstone National Park in the United States, reveals how they supercharge the nitrogen cycle, benefiting other plant eaters. As policymakers consider whether to reintroduce bison more widely, the research suggests that land can support more grazing than allowed by current recommendations, as long as the animals are allowed to range in a large-enough area. “Buffalo helped shape this continent,” says bison-management specialist Troy Heinert. “The more buffalo that are out there, the ecosystems are improved for all other animals as well.”

The New York Times | 5 min read
Reference: Science paper

How bad are ultra-processed foods, really?

Since the term ‘ultra-processed foods’ (UPFs) was coined in 2009, dozens of studies have linked the group with a range of health problems. Such research has been influential — the governments of countries such as Brazil, France and Israel all advise people to avoid UPFs — and the evidence does suggest that diets high in UPFs are associated with conditions from obesity to depression. But some scientists are sceptical — they argue that the term is too loose to be useful for research or to guide people’s decisions about how to eat.

Nature | 12 min read

Sacks of seeds without the sex

Agriculture is on the brink of a revolution: grain crops that produce seeds asexually. The technology — trials of which could start sprouting as early as next month — exploits a quirk of nature called apomixis, in which plants create seeds that produce clones of the parent. Apomixis could slash the time needed to create new varieties of crops, and give smallholder farmers access to affordable high-yielding sorghum (Sorghum bicolor) and cowpea (Vigna unguiculata). But before self-cloning crops can be commercialized, the technology must run the regulatory gauntlet.

Nature | 11 min read

Hello Nature readers,
Today we enjoy the month’s best science images, learn that spouses tend to share the same psychiatric disorders and hear from nine former directors of the CDC who are sounding the alarm about US health secretary Robert F. Kennedy Jr.

The month’s best science images

Ocean photographer Andrey Shpatak snapped this colourful pea crab (Pinnotheres pisum) in Rudnaya Bay, just off the southeastern coast of Russia. His timing was a stroke of luck, he says. Pea crabs live most of their lives hidden inside the shells of mussels. “I can only assume that this pea crab was looking for a home when I managed to photograph it,” says Shpatak. The lucky shot was a finalist in Oceanographic magazine’s 2025 Wildlife Photographer of the Year competition.

See more of the month’s sharpest science shots, selected by Nature’s photo team.

Nature | Leisurely scroll

Spouses share psychiatric disorders

People with a psychiatric disorder are more likely to marry someone who has the same condition than to partner with someone who doesn’t. Using data from more than 14.8 million people, researchers found that when one partner was diagnosed with one of nine conditions after marriage, the other was significantly more likely to be diagnosed with the same condition. “The pattern holds across countries, across cultures, and, of course, generations,” says population-and-genetics researcher Chun Cheih Fan, who co-authored the study.

Nature | 4 min read
Reference: Nature Human Behaviour paper

AI-assisted research sleuthing

Researchers have identified more than 1,000 potentially problematic open-access journals using an artificial intelligence (AI) tool designed to screen titles for signs of dubious publishing practices. None of the journals it flagged has previously been on any kind of watchlist, and some titles are owned by large, reputable publishers. The tool isn’t designed to replace human evaluations of the integrity of journals and papers, says computer scientist Daniel Acuña, who designed it. But it could be used to speed up such assessments.

Nature | 5 min read
Reference: Science Advances paper

‘Aha’ moments made visible

In Flashes of Brilliance, writer and photo editor Anika Burgess captures the dual nature of scientific images: a tool for discovery and a medium for communication. As a guide through the history of scientific photography, Burgess celebrates the ability of an image to wordlessly crystallize a complex idea, while acknowledging their potential to mislead if manipulated. The book “challenges us to be more thoughtful, not just in making images but in seeing them”, says science photographer Felice Frankel in her review.

Nature | 7 min read

Why a journal bans hype

A new study in Communications Psychology finds that extolling the novelty or importance of a paper in its abstract increases online attention and citations. But the journal’s editors don’t allow such promotional language in its own pages. In an editorial, the journal explains why it’s “so mean” when it comes to banning hype. “Novelty claims lead to unproductive disagreement,” it argues, and it’s unclear what makes a ‘first’ anyway. Hype exacerbates the gender gap: if women use hype, their work doesn’t benefit as much as men’s. In any case, “it is not the authors but the expert readers who are best placed to judge the work, who may feel ‘amazed’ and who can most credibly assign the label of ‘incredibly valuable contribution’”.

Communications Psychology | 4 min read
Reference: Communications Psychology paper