Neanderthals separated from humans, Homo Sapiens, about 400,000 years ago, but then, in Eurasia, the two species, who were believed to be unable to interbreed, came back together again, and did. We know this because every population in the world, except for Africa, carries both Neanderthal and/or Denisovan DNA, including aboriginal people from Australia. This information, newly discovered in the past year or so, raises a lot of thorny questions.
Neaderthals have been grouped as a separate species from Homo Sapiens, modern man, and members of two different species, by definition, are not supposed to be able to interbreed and have fertile offspring. So are Neanderthals and Homo Sapiens really the same species?
Neanderthals, as a separate species became physically extinct about 30,000 years ago, at least we can no longer find fossil records of them. But did they really, or did they simply assimilate and genetically, and physically, become the new us?
And if that wasn’t enough, there are the Denisovans and they too interbred with Homo Sapiens. In fact, Denisovan and Neanderthal bones have been discovered together, and Denisovans are believed to be an offshoot of Neanderthals. And what about the Hobbits of Flores Island? Where and how do they fit in?
And there are probably more surprises that await us, because there are more fossilized bones that we have not been able to obtain DNA from that don’t match any of the groups mentioned above. In the future, discoveries of fossilized bones will likely be made that from which we will be able to recover DNA, as the recovery techniques improve.
But what does all of this mean? How does it affect what we knew, or thought we knew, about the “Out of Africa” theory that says all contemporary man evolved in African, left Africa and subsequently killed off or replaced all of the other species, such as Neanderthals? If that’s not true, what is true? Did we evolve out of African several separate times, getting reacquainted some several 10s (or hundreds) of thousands of years later on another continent?
All of this unexpected mixture causes lots of questions, and today, we don’t have many answers. But maybe the biggest question is that of what, exactly, is a modern human?
CHRISTOPHER STRINGER is one of the world’s foremost paleoanthropologists. He is a founder and most powerful advocate of the leading theory concerning our evolution: Recent African Origin or “Out of Africa”. He has worked at The Natural History Museum, London since 1973, is a Fellow of the Royal Society, and currently leads the large and successful Ancient Human Occupation of Britain project (AHOB). His most recent book is The Origin of Our Species (titled Lone Survivors in the US).
Here’s what Christopher has to say:
“At the moment, I’m looking again at the whole question of a recent African origin for modern humans—the leading idea over the last 20 years. This argues that we had a recent African origin, that we came out of Africa, and that we replaced all of the other human forms that were outside of Africa. But we’re having to re-evaluate that now because genetic data suggest that the modern humans who came out of Africa about 60,000 years ago probably interbred with Neanderthals, first of all, and then some of them later on interbred with another group of people called the Denisovans, over in south eastern Asia.”
To read more of Christopher’s thoughts, click here. They are very interesting and enlightening indeed, from a man who has been in this field since the beginning, a mere 40 years ago.