The dispersal of anatomically modern Homo sapiens out of Africa and across Eurasia provides a unique opportunity to examine the impacts of genetic selection as our species adapted to multiple new environments. An analysis of ancient (1,000 to 45,000 years old) Eurasian genomic datasets reveals signatures of strong selection, including at least 57 hard sweeps after the initial human movement out of Africa, which have been obscured in modern populations by extensive admixture during the Holocene. In new research, scientists identified a previously unsuspected extended period of genetic adaptation lasting around 30,000 years, potentially in the Arabian Peninsula area, prior to a major Neanderthal genetic introgression and subsequent rapid dispersal across Eurasia as far as Australia.
“Ancient human genomes make it possible to recover key events in the evolution of our species that are essentially hidden from modern human genomes,” said Dr. Raymond Tobler, a researcher at the Australian National University.
“We suspect the ’Arabian Standstill’ period was a pivotal point in our evolutionary history, during which the ancestors of all non-African humans underwent extensive genetic adaptation to colder environments, effectively preparing them for the cool Eurasian environments they would eventually encounter.”
In their research, Dr. Tobler and his colleagues used ancient human genomes to reconstruct historical adaptation during the poorly understood out-of-Africa diaspora.
They found specific genetic patterns that pointed to a series of natural selection events dating back 80,000 years.
These patterns suggest the ancestors of modern humans living outside of Africa experienced an extended period of genetic isolation and adaptation, possibly around the Arabian Peninsula, prior to their worldwide dispersal 50,000 years ago.
“These ancient adaptive genes share striking functional similarities with selected genes found in human and mammalian populations…
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