Although there is evidence that Homo erectus arrived in Europe (from Africa, via southwest Asia) around 1.4 million years ago, there seems to have been a more recent period of around 200,000 years when the continent was entirely devoid of humans.
Researchers have identified a previously unknown extreme cooling period that occurred around 1.1 million years ago, resulting in the temporary disappearance of humans from Europe.
The discovery of this “big freeze” came from computer simulations based on sediment cores taken from the seabed off the coast of Portugal. The computer models suggest that average winter temperatures would have dropped by around 8 degrees Fahrenheit. This would likely have been unsurvivable for early humans who had not yet learned to reliably control fire, build well-insulated dwellings, or make warm clothes. Such a change in climate would also have dramatically altered the food supply of these hunter-gatherers.
The researchers aren’t sure whether these hominins (namely Homo erectus) died out or left Europe, but according to the archeological and fossil record, there is a gap of human remains and tools from 1.1 million years ago until 900,000 years ago, which coincides with the “big freeze” noted by computer models.
Whatever happened, hominins returned around 200,000 years later – though apparently in the form of a more modern human ancestor, Homo antecessor, which may have benefitted from certain physical adaptations or technological innovations that helped it survive the cooler temperatures (though the big freeze was over by then). After that, Europe's hominins never left, with Neanderthals emerging around 400,000 years ago.
- The cooling period of 1.1 million years ago was probably caused by the melting of a large ice sheet that significantly weakened an ocean current known as the Atlantic Meridional Overturning Circulation.
- The new study, co-authored by scientists at University College London, South Korea’s Pusan National University, and the Natural History Museum in London, among other institutions, contradicts the long-established belief that after early humans arrived in Europe around 1.4 million years ago, they never left.
- Although anatomically modern human emerged in Africa around 300,000 years ago, Homo sapiens only arrived in Europe around 42,000 years ago. Homo sapiens and Neanderthals briefly co-existed in Europe before the latter went extinct around 40,000 years ago.