On the basis of fossil and archaeological data it has been
hypothesized that the exodus of Homo sapiens out of Africa and into
Eurasia between ∼50-120 thousand years ago occurred in several
orbitally paced migration episodes. Crossing vegetated pluvial
corridors from northeastern Africa into the Arabian Peninsula
and the Levant and expanding further into Eurasia, Australia
and the Americas, early H. sapiens experienced massive time-varying
climate and sea level conditions on a variety of timescales.
Hitherto it has remained difficult to quantify the effect of glacial- and
millennial-scale climate variability on early human dispersal
and evolution. Here we present results from a numerical human
dispersal model, which is forced by spatiotemporal estimates of
climate and sea level changes over the past 125 thousand years.
The model simulates the overall dispersal of H. sapiens in close
agreement with archaeological and fossil data and features
prominent glacial migration waves across the Arabian Peninsula
and the Levant region around 106-94, 89-73, 59-47 and 45-29
thousand years ago. The findings document that orbital-scale
global climate swings played a key role in shaping Late Pleistocene
global population distributions, whereas millennial-scale abrupt
climate changes, associated with Dansgaard-Oeschger events, had
a more limited regional effect.