Much is known about this migration because it was successful and it left a DNA trail to prove it. Evidence that this migration started as a small group is observable in the pronounced reduction of the genetic diversity in all of today’s non-Africans. This kind of thing happens when a small population expands rapidly into a large, unpopulated territory. Furthermore, there is a continuous decrease in genetic diversity the farther one travels from Africa. 1
And once the Migrants passed through Neanderthal territory in the Near East and then into Southeast Asia their genetic trail shows that they interbred with yet another archaic human group, the Denisovans. The DNA of today’s Indigenous Australians, among others, bears witness to this ancient tryst.2
Helicobacter pylori is a human-host gastric pathogen. It, to, went through a genetic bottleneck at the time of the Africa migration. Its greatest genetic diversity is found today in East Africa and its diversity decreases as its distance from East Africa increases. It left East Africa approximately 58,000 years ago.3
Two predators occupying the same ecological niche will be mortal enemies.4 Witness the lion and leopard, the wolf and coyote, the grizzly and black bear and predictably Neanderthals and Migrants. Europe is a big place especially if one is on foot. Yet in only a few thousand years after the Migrants entered Europe ~45,000 years ago, the Neanderthals were gone.5 Their 360,000 year reign had abruptly ended. (Note, this was not the first time the Migration entered Europe. It previously failed in Southern France ~54,000 years ago,... discussed later.)
Did the Upper Paleolithic sewing needle usher the Neandertal into extinction? There is a lot to be said for warmer clothes but no matter how well we dressed our apparel surely did not intimidate the Neanderthal who were killers of giant straight-tusked elephants, woolly rhinoceroses, woolly mammoths and each other.6,7 The Neanderthal’s more immediate concern, after the Migrants arrived, was a new kind of sudden and unexpected death.
Something got invented in Southern Africa that predated both the Migration and the sophisticated Upper Paleolithic culture. It was a game changer. It was a work of genius.