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A prehistoric hunt is portrayed in this replica of a painting from the Cave of Altamira in Cantabria, Spain. (World History Archive/Alamy)
Did humans evolve to run down prey?
A new study suggests that running down prey can be more efficient than slowly stalking it — which could explain why humans evolved muscles optimized for prolonged movement, the ability to sweat a lot and heat-shedding bare skin. For example, at human running speed, it’s possible to drive an antelope to exhaustion in only 24 minutes. This approach could result in a five-times bigger payoff in calories gained per time invested, compared to hunting the animal down at a walking pace. The authors of the study also found nearly 400 historical reports of endurance pursuits by Indigenous peoples around the globe, far more than were previously known. Some researchers are sceptical that persistence hunting played a major part in shaping human evolution: other methods are documented more frequently in the historical record, says biological anthropologist Cara Wall-Scheffler.
Reference: Nature Human Behaviour paper
Breast cancer in women of African ancestry
The largest-ever genome-wide association study (GWAS) for breast cancer among women of African ancestry found 12 genetic locations linked to risk. One gene variant, near chromosome 2q14.2, was particularly strongly linked to a higher risk of triple-negative breast cancer, a more aggressive type. “Such a strong association is rarely observed in GWAS of cancers,” write the study authors. When researchers built a polygenic risk score for women with African backgrounds using this new data, it did a better job of predicting risk than other scores, which are derived from data that mostly comes from females of Asian and European ancestry.
Reference: Nature Genetics paper
2023 summer was hottest in 2,000 years
Evidence from tree rings shows that the summer of 2023 was the hottest in 2,000 years. Last year was already established as officially the hottest on record. The latest analysis puts that peak into the context of the natural variability in temperatures. The Northern-Hemisphere summer of 2023 was at least 0.5 ℃ hotter than 246 AD, which tree growth rings suggest was the hottest year before the industrial revolution kicked off human-caused climate change.
Scientific American | 5 min read
(Amanda Montañez; Source: “2023 Summer Warmth Unparalleled over the Past 2,000 Years,” by Jan Esper et al., in Nature. Published online May 14, 2024)
Features & opinion
How to kill ‘zombie’ cells that make you age
Researchers are on the hunt for senolytics — therapies that destroy senescent cells. These ‘undead’ cells build up as we age, spewing out noxious biological signals that can slow cognition and weaken the immune system. Among the about 20 ongoing clinical trials is a drug that reverses diabetes-related vision loss by killing senescent cells in the blood vessels supplying the retina. “I think within the next five years we may see this treatment for diabetic macular oedema being offered in the clinic,” says endocrinologist Sundeep Khosla. Killing just zombie cells, without harming healthy ones, remains a problem. “Without having really great biomarkers of senescent cells, it’s a little bit tricky to engage the right targets,” says geriatric-medicine researcher Miranda Orr.
Why men became good fathers
In her book Father Time, primatologist Sarah Hrdy takes us on a quest to discover when and how men — unlike other male great apes — began to nurture their young. When our ancestors became cooperative breeders, with groups of parents raising children together, natural selection favoured men who were more cooperative, Hrdy argues. She suggests that the advent of agriculture masked this truth: it brought with it the need to protect resources, which increased the segregation of men and women in domestic and social spheres. Although Hrdy’s model for how male care evolved is necessarily speculative, her broad, accessible writing is a joy to read, says biological anthropologist and reviewer Kermyt Anderson.
How AI can revolutionize mathematics
“Giving birth to a conjecture — a proposition that is suspected to be true, but needs definitive proof — can feel to a mathematician like a moment of divine inspiration,” writes mathematician Thomas Fink. Yet conjectures could be the ideal testing ground for AI-assisted discovery, he argues. Training data are abundant and cheap. And “there are no coincidences in maths… a single counterexample leaves a conjecture dead in the water”. Mathematicians’ imagination and intuition will still be required, though, to understand which conjectures will help us to reach new mathematical frontiers.
