Max Planck Institute for Evolutionary Anthropology
A new study reveals why the first migrations disappeared without a trace.
We tend to see human history as a constant and inevitable march across the globe. But the reality is much more confusing — and much more tragic. Archaeological evidence demonstrates that modern humans reached Eurasia several times long before the great migration which ended up being fixed.
Most of these early pioneers were evolutionary dead ends. They left stone utensils behind, but your DNA does not exist nowhere in current populations.
A new, pre-published in Research Squarenow explains why these first forays into the unknown were doomed to failure.
Around 100,000 years ago, small groups of modern humans arrived at Arabian Peninsula. We know this because they left behind distinctive stone tools on a plateau in what is now southern Oman.
Archaeologists have recently dated several of these sites, concluding that they were occupied between about 109,000 and 95,000 years ago. The utensils belong to a distinctive technique known as Nubian-Levallois technologyfirst developed in northeast Africa.
At the time, Arabia was not a wilderness. It was a lush territory of pastures, abundant springs and grazing animals. For a few thousand years, these pioneers prospered.
Then the rains stopped. Around 95,000 years ago, the climate changed with bewildering brutality. The lakes disappeared. The springs turned to dust. The archaeological record reflects this change perfectly: stone utensils simply disappear.
Without a continuous flow of new migrants from Africa to reinforce their numbers, these isolated groups will have languished to extinction. They were, as the researchers said, “demographically fragile“.
According to the study authors, without continued migration from Africa, these isolated groups would then likely have withered and disappeared.
Previous migrations depended on “green corridors” — temporary windows of favorable weather conditions that allowed populations to cross deserts that were once inhospitable.
But around 70,000 years ago, something has changed in Africa. Humans began to inhabit a wider and more demanding range of environments. These early pioneers were vulnerable. The successful migration only worked because humans had adapted beforehand, explains .
Possible migratory waves from Africa
According to Eleanor Scerrifrom the Max Planck Institute for Geoanthropology, the humans who finally conquered Eurasia after 60,000 years ago had developed a “distinctive ecological flexibility.” They no longer simply waited for the rains to return. They had learned to deal with unpredictable habitats.
At about the same time, other groups may have advanced north toward the eastern Mediterranean. Some even found Neanderthals, passing on a small amount of genetic material to these populations before they themselves disappeared. None of these explorers, however, contributed substantially to the ancestry of people living today.
After all, our expansion across the globe It wasn’t a singular victory.. It was the final chapter in a long series of experiments. We are the descendants of the group that finally discovered how to survive the failures of those who came before, the study authors conclude.
