Proper noun
the Sahara pump theory
A hypothesis that explains how flora and fauna migrated between Eurasia and Africa via a land bridge in the Levant region, based on the idea that there were periods of abundant rainfall lasting thousands of years in Africa and associated with a "wet-green Sahara" phase, during which larger lakes and more rivers existed.
According to the Sahara pump theory evidence suggests that genus Homo have migrated out of Africa at least three and possibly four times (e.g. Homo erectus, Homo heidelbergensis and two or three times for Homo sapiens). Source: Internet
The Sahara pump theory explains how flora and fauna (including Homo sapiens ) left Africa to penetrate the Middle East and beyond. Source: Internet