Two fossil skulls from Apidima, Greece, tell an intriguing story. The first, more than 210,000 years old, appears to be an early Homo sapiens. The second, a younger 170,000 years old, looks like a Neanderthal.
If so, then Homo sapiens moved to Greece, were replaced by Neanderthals, then thousands of years later moved back and replaced the Neanderthals (“replaced” is generally a polite word for “killed.”)
This is consistent with a fair amount of other evidence that Homo sapiens had (at least) two out-of-Africa events, of which the one that killed the Neanderthals was only the most recent. It could also represent the population wave that interbred with Neanderthals, contributing Sapiens DNA to the Neanderthal genome, well before the more famous interbreeding event when Neanderthal DNA entered our modern Homo sapiens genome.
On the other hand, there’s not a whole lot to these fossils. One is just the back of a skull. The back of a skull is more informative than it sounds on first glance because neanderthals have a bump (referred to as a “bun”) on the backs of their skulls that we don’t, but still, we’re not talking about complete skulls. So it could turn out that this was just a funny looking Neanderthal, or a piece that got pressed weirdly by a rock (the first Neanderthal skeleton people found had arthritis, which threw all of the illustrations off for decades, so these things can happen).
But throwing caution to the wind, let’s assume the skulls are correct, and so is the rough timeline I sketched out: Neanderthals inhabit Europe, Sapiens leave Africa, Sapiens push into the Middle East and Greece, Sapiens fail, Neanderthals retake the region, years pass, Sapiens try again and this time succeed, wiping out the Neanderthals.
What changed? What made the first attempt a failure and the second successful?
Aside from Sapiens generally getting smarter, I suggest a humble invention: the sewing needle.
We know from studies of lice (ew, I know) that humans began wearing clothes around 80-170,000 years ago. How do we know? Because the lice that live on our heads and the lice that infect our clothes are different species, and genetics claims that’s when they split.
The earliest known “looks like a needle” comes from Sibudu Cave, South Africa, and dates from about 61,000 years ago, but needles are small and easily broken, so I suspect that plenty were used that we haven’t found.
Neanderthal sites show no evidence of tools for making tailored clothing. There are only hide scrapers, which might have been used to make blankets or ponchos. This is in contrast to Upper Paleolithic (modern human) sites, which have an abundance of eyed bone needles and bone awls. Moreover, microwear analysis of Neanderthal hide scrapers shows that they were used only for the initial phases of hide preparation, and not for the more advanced phases of clothing production.— John F. Hoffecker, The Spread of Modern Humans in Europe
If the Neanderthals did not have clothes, then they had to adapt to the European climate in other ways–probably fur.
(Incidentally, according to the only data I have on the matter, Mediterranean and Nordic peoples are oddly hairy, while Siberian people are weirdly not-hairy. If anyone has any idea why this is I’d love to hear it.)
If the first wave of Sapiens to leave Africa also did not have clothes (or had only very rudimentary clothes) and they lacked the Neanderthals’ fur, then they would have had a very difficult time surviving in the harsh European winters.
Like the Roanoke colony, the survivors may have happily gone over to the Neanderthal side.
By the time the second wave of Sapiens showed up, however, they had invented clothes–and had other elements of a more advanced cultural/technological toolkit that let them conquer the elements–and the ‘Thals.