A new study published in the journal Science by an international team finds that past changes in atmospheric CO2 and corresponding shifts in climate and vegetation played a key role in determining when and where early human species interbred.
Modern-day people carry in their cells a small quantity of DNA deriving from other human species, namely the Neanderthals and the elusive Denisovans.
Back in 2018, scientists announced to the world the discovery of an individual, later nicknamed Denny, who lived 90,000 years ago and who was identified as a daughter to a Denisovan father and a Neanderthal mother (Slon et al. 2018). Denny, along with fellow mixed-ancestry individuals found at Denisova cave, testifies that interbreeding was probably common among hominins, and not limited to Homo sapiens.
To unravel when and where human hybridization took place, scientists usually rely on paleo-genomic analysis of extremely rare fossil specimens and their even scarcer ancient DNA content.
In the new Science paper, the team of climate experts and paleo-biologists from South Korea and Italy pursued a different approach. Using existing paleo-anthropological evidence, genetic data and supercomputer simulations of past climate, the team found that Neanderthals and Denisovans had different environmental preferences. More specifically, Denisovans were much more adapted to cold environments, characterized by boreal forests and even tundra, compared to their Neanderthal cousins who preferred temperate forests and grassland.
2023-08-10 14:00:04
Original from phys.org