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The black-ringed ‘leopard spots’ on a Martian rock might be evidence of chemical reactions that could have involved microorganisms. Credit: NASA/JPL-Caltech/MSSS
Dark-rimmed ‘leopard spots’ in a rock studied by NASA’s Perseverance rover last year could be the remains of microbial activity on Mars. The rings aren’t a sure sign that microbes once thrived on the Red Planet; the only way to know for certain is to analyse a sample of the leopard-spotted rock here on Earth. Perseverance has a sample awaiting a ride off Mars for precisely that purpose. For now, the rings are being treated as ‘an intriguing signal’ of ancient Martian life, but far from a sure thing, said researchers at a conference yesterday.
Researchers have identified 64 genes that help to shape how quickly a person’s brain ages. The team analysed brain scans from nearly 40,000 people and calculated each person’s ‘brain age gap’ (BAG) — the difference between their predicted brain age and their chronological age. Using genetic data from just over 31,000 healthy participants from the cohort, the team homed in on 64 genes linked to BAGs, some with roles in blood clotting and cell death. They also pinpointed 13 potential drugs that have been explored in clinical trials that could be used to target these genes.
Reference: Science Advances paper
A genomic study of people who lived more than 6,000 years ago hints that ancient European hunter-gatherers might have voyaged across the Mediterranean to Africa. Using DNA from bones or teeth from nine individuals found at archaeological sites in the eastern Maghreb region — present-day Tunisia and northeastern Algeria — researchers found that Stone Age populations who lived there were descended, in part, from Europeans. At that time, there were more islands poking above the waves in the narrow strait between what’s now Sicily and Tunisia, which could have eased the journey for ancient voyagers in simple boats.
Researchers have forged relatively large sheets of metal that are just atoms thick. The team took inspiration from ancient copper forging techniques to squish molten droplets of metals such as bismuth, lead and tin into 2D sheets in a tiny sapphire anvil. This allowed them to study how the properties of super-thin sheets of the metals differ from 3D chunks of the same material. The team now have their sights on a new design that they hope will extend the technique to work with metals that have melting points above 500 ℃.
Source: Adapted from Figure 1a of ref. 1.
Features & opinion
While researching the infamous Stanford Prison Experiment for a book, social scientist Thibault Le Texier was struck by how quickly it all falls apart under scrutiny. The ethics of the mock jail study — which described undergraduate volunteers descending into sadism and breakdown — are questionable at best. Lead researcher Philip Zimbardo might have pinched the design of the study from junior team members without crediting them, and the results were sent to the media immediately, with no peer review in sight until 1973 — two years after the experiment concluded. The myriad problems Le Texier highlights raise a question, writes sociologist Augustine Brannigan: should the study be retracted? It might not even be possible — the journal that eventually published the paper no longer exists. “If Le Texier’s findings are credible, arguably the best outcome we can expect is more responsible reporting in contemporary textbooks,” Brannigan writes.
Retraction Watch | 14 min read
“Elisabeth Vrba’s meticulous studies of fossil and living mammals challenged the conventional view of evolution” writes palaeontologist Niles Eldredge. Among the achievements of Vrba, who has died aged 82, was a solution to a problem that Darwin grappled with throughout his career: “how could the great diversity of species over vast stretches on continental areas have occurred in the absence of obvious barriers that would cause reproductive isolation?” Vrba’s answer was that cataclysmic environmental changes can fragment and isolate habitats, and cause waves of extinction and evolution.
Image of the week
A machine running the AI model Gemini Robotics places a basketball in a hoop.Credit: Google DeepMind
A team at Google DeepMind has put a version of its large-language model Gemini into a robot arm. With Gemini’s help, the arm can ‘slam dunk’ a miniature basketball through a desktop hoop — despite never having watched another robot do the action, says the firm. The hope is to create machines that are intuitive to operate and can tackle a range of physical tasks, without relying on human supervision or being preprogrammed. (Nature | 4 min read) (Google DeepMind)
Today I’m trying harder to understand how dogs are feeling. You might think that interpreting a dog’s emotions from its body language is easy, but it turns out that we’re actually pretty bad at it. Researchers found that we tend to pay attention to the surroundings of our canine friends to glean context as to whether they’re excited, sad or scared, rather than looking at what they’re actually doing. Co-author Clive Wynne is taking the results to heart, using the findings to “guide [his dog’s] life toward greater happiness”, and so am I.
While I find a dog to emotionally connect with, why not send your feedback on this newsletter to [email protected]?
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Jacob Smith, associate editor, Nature Briefing
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