Who are you calling Neanderthal?
Neanderthals, Homo neanderthalensis, were the now-extinct cousins of our own species, Homo sapiens. In popular culture, the term is often used as an insult towards someone exhibiting primitive or perhaps violent behaviour. But get this: you’re most likely part-Neanderthal!
But let’s back it up a bit, to about 500-600 thousand years ago.
We begin our story in early Africa, where the ancient human species Homo heidelbergensis once called home. A subset of this population migrated from their homeland and split up; one group to West Asia and Europe, the other to South Asia. The former group eventually speciated to become the Neanderthals, and the latter becoming the Denisovans—a group only recently discovered within the last ten years. The group remaining in Africa were our ancestors; the precursors of the human race, homo sapiens. We will circle back to these guys in a bit.
Now, let’s get down to the saucy details: reproduction.
As mentioned earlier, the Neanderthals and Denisovans went their separate ways across the planet, where they set up camp and began to reproduce, slowly transitioning into their own unique species over time.
Now, let’s quickly get back to our ancestors back in Africa; 70,00 years ago, long after their cousins left, the early Homo sapiens emigrated from their home range to expand across the globe. Along their journey to new horizons, they encountered their not so distant relatives. And they seemed to get along very well. By that, I mean that the early humans began mating with the early Neanderthals and Denisovans.
Now, ordinarily, if members of two separate species attempted to mate, the copulation would not result in fertile offspring. However, these hominids were still closely related and shared a great deal of their genes with each other, despite being distinct enough to warrant independent classification. So, their attempts were not fruitless; interbreeding was successful.
So where do you fit in to all of this?
Well, if you are of European or Asian decent, you most likely have Neanderthal DNA in your cells! These archaic members of our genus have contributed between 1-4% of their genetic material to modern Eurasians.
Not only that, but many people in Asia and the Pacific Islands have received genes form their Denisovan ancestors! Melanesians specifically (those local to the Melanesian region in the southwestern Pacific Ocean), share 3-5% of their DNA with their Denisovan ancestors.
Contrastingly, for people in African populations, the number of shared genes with either species of early humans is close to zero, as the predecessors of the Neanderthals and Denisovans left the continent well before they diverged into their own species.
Where did they go?
So, according to the genetic evidence we have available today, these species were obviously around when humans began expanding our distribution. So, where did they go?
Well, we don’t actually know for sure!
Naturally, there are many theories to try and fill in this ever-puzzling gap in the history of human evolution. One suggests that humans out-competed the Neanderthals; that despite their burly structure, we were better suited to the changing environment and persisted while our European cousins perished. Neanderthals were adapted to survive in colder climate and were specialised hunters of large Ice Age mammals. However, as the planet began to warm, it is said that Homo sapiens began to thrive.
On the other hand, some believe we directly killed the Neanderthals, culling them to their extinction.
A theory that I believe to be particularly compelling, however, is that the Neanderthals disappeared from our world because they were absorbed into our own human lineage. This theory suggests that the increase of gene flow between the two populations through interbreeding caused the Neanderthal genome to melt into our own.
In short, depending on your cultural background, you just might be part caveman! But don’t fret; despite popular belief, Neanderthals were quite intelligent. They created impressive and highly functional stone tools for hunting, and buried their dead, showing to have some concept of a potential afterlife. When you think about it, they weren’t so different from our early human ancestors. So, not such an insult after all! Better think about that next time you start calling names!
Bonus Fun: Check out this site for a fun analysis of early humans depicted in cartoons!