2011 Science News of the Year: Humans
By Science News
While the Han Chinese (left) don’t show genetic contributions from Denisovans, Australian Aborigines (right) do.
BLACKRED/ISTOCKPHOTO; GARY RADLER/ISTOCKPHOTO
Asia takes a bow
Often overlooked as a geographic player in human evolution, Asia has stepped into the scientific spotlight. New comparisons of ancient and modern DNA indicate that Stone Age humans migrated to Asia in two stages.
At least 44,000 years ago, initial arrivals in Southeast Asia interbred with a humanlike population known as Denisovans that apparently had spread southward from Siberia. Denisovans contributed a portion of genes to living New Guineans (SN: 1/15/11, p. 10), Australian Aborigines and groups on nearby islands (SN: 11/5/11, p. 13). A second human influx gave rise to today’s East Asians, with no Denisovan dalliances, starting between 38,000 and 25,000 years ago, geneticist Morten Rasmussen of the Natural History Museum of Denmark in Copenhagen and his colleagues find. The work builds on previous genetic evidence that Homo sapiens interbred with Neandertals in West Asia before heading east.