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The early human species Homo heidelbergensis (skull shown) might have been able to spread across Earth because wetter, more migration-friendly weather conditions arose, according to a climate model.Credit: Javier Trueba/MSF/Science Photo Library
How climate shaped human ancestry
A record-breaking simulation of the past two million years of Earth’s climate provides evidence that temperature and other planetary conditions influenced early human migration — and possibly contributed to the emergence of the modern-day human species around 300,000 years ago. “This is another brick in the wall to support the role of climate in shaping human ancestry,” says marine geologist Peter de Menocal.
Leech blood points to wildlife whereabouts
DNA extracted from blood ingested by leeches has been used to track wildlife in China’s Ailaoshan Nature Reserve. More than 160 park rangers went hunting for the parasites along their regular patrol routes, gathering 30,468 leeches in three months. Researchers then extracted DNA from the leeches’ blood and detected 86 different species, from endangered Yunnan spiny frogs (Nanorana yunnanensis) to Asiatic black bears (Ursus thibetanus) and humans. Biodiversity was highest in the high-altitude interior of the reserve, suggesting that human activity had pushed wildlife away from other areas.
Reference: Nature Communications paper
Video: why giraffes live longer than ferrets
It is well known that somatic mutations — which occur in the body’s genetic code and accumulate over time — can cause cancer, but their broader role in ageing is less clear. Now, researchers have measured the somatic mutation rates of a range of mammals and discovered a striking correlation between this rate and lifespan — lending evidence to the theory that the mutations are a cause of ageing, rather than a result of it.
Features & opinion
The AI protein-folding revolution
Last July, London-based firm DeepMind made public an artificial intelligence (AI) tool called AlphaFold. The software could predict the 3D shape of a protein from its genetic sequence with, for the most part, pinpoint accuracy. Since then, AlphaFold mania has gripped the life sciences. In some cases, the AI has saved scientists time; in others, it has made possible research that was previously inconceivable in areas ranging from drug discovery and protein design to the origins of complex life.
Big plans for massive rockets
Astronomers are beginning to dream of how a new generation of megarockets might enable revolutionary space telescopes and bigger, bolder interplanetary missions. NASA’s Space Launch System and SpaceX’s Starship are large and powerful enough to transport heavy, complex spacecraft farther, and faster, than ever before. “Starship holds the promise of transforming the Solar System in a way we can’t really appreciate,” says planetary scientist Alan Stern. “It completely changes the game.”
Scientific American | 12 min read
Standing up for jailed scholars
Conservation scientist Morad Tahbaz is one in a lengthening list of people involved in scientific activities who are being jailed in Iran for spying. Tahbaz and seven colleagues are currently serving ten-year sentences for research that used camera traps to monitor endangered cheetahs. The scientific community must do more to raise its voice in support of scholars who have been wrongly imprisoned, says a Nature editorial.
