Past climate change swings orchestrated early human migration waves out of Africa

A small group of Homo sapiens left Africa around 100,000 years ago in a series of astronomically-paced slow migration waves and arrived for the first time in southern Europe around 80,000-90,000 years ago, according to a new study published in the journal Nature. These results by a team of researchers from SOEST challenge prominent anthropological models that assume a single exodus out of Africa around 60,000 years ago.

The wobble of Earth’s axis, with a period of about 20,000 years, and the corresponding changes in climate are known to have caused massive shifts in vegetation in tropical and subtropical regions. Such shifts opened up green corridors between Africa, the Sinai and the Arabian Peninsula, enabling some Homo sapiens to leave Northeastern Africa and embark onto their grand journey into Asia, Europe, Australia and eventually into the Americas. Whether climate shifts really influenced the early human migration has been a matter of intense debate.

Researchers from the International Pacific Research Center (IPRC) used one of the first integrated climate-human migration computer models in an attempt to re-create quantitatively the grand journey of Homo sapiens over the past 125,000 years and determine the role of climate in human dispersal. The model simulates ice-ages and abrupt climate change and captures the arrival times of Homo sapiens in the Eastern Mediterranean, Arabian Peninsula, Southern China and Australia in close agreement with paleoclimate reconstructions and fossil and archaeological evidence.

Watch the video on Vimeo, listen to the interview with Timmermann on Hawaii Public Radio, and read more at LiveScience, Science Magazine, New Scientist, The New York Times, and UH News.