A few years ago the entire Neanderthal genome was mapped and from that genetic evidence we know that they interbred with Homo sapiens (modern humans) outside of Africa. In fact, it is from that genetic sequencing that we also know that not only did H. sapiens mate with Neanderthals but also with a group known as the Denisovans and the result is a very complex family tree as it appears all three hominin species were mating with each other. However, the sequencing of the Neanderthal genetic code also revealed a mystery among other things. It seems that the Denisovans shared up to 8% of their genome with a “super archaic” and unknown hominin species that dates back to around 1 million years ago.
Another interesting discovery from the Neanderthal DNA genome is that Native Americans and Asians have a higher proportion of Neanderthal DNA in their genes but small percentages of Denisovan DNA. Additionally, 6% of the genome of Australian Aborigines and indigenous Papua New Guineans belong to the Denisovan species. Further, Denisovan DNA is also found in the Han Chinese (East Asia natives) and the Dai People of Southern China. The Karitiana people who are indigenous to Brazil along with some others in the same region are not only related to both Denisovans and Neanderthals but their genome shows that they have a relatively high genetic contribution from the Denisovans!
Back in 2013 study results were presented at a meeting of the Royal Society in London revealing that Denisovan DNA contains a segment that comes from a currently unknown hominin species. Along with that discovery it appears that interbreeding between ancient human species was rather rampant and frequent 30K years ago. But who was this mystery species that they were mating with? It’s a species that is neither Neanderthal NOR HUMAN!
Since these finds were announced scientists have been debating just who and what this mystery species was. Some have suggested it was a branch of hominin that branched off from Homo heidelbergensis from Africa or Europe. H. heidelbergensis, Heidelberg Man, is believed to be the common ancestor of modern humans, Neanderthals, and Denisovans by some scientists. Others have absolutely no idea what the mystery species was that the Denisovans were mating with. Please realize, however, that the Denisovan DNA evidence suggests that the mystery species was neither Neanderthal OR HUMAN. Heidelberg Man was an archaic human so in my mind that eliminates him from the realm of suspects.
Traces of this unknown non-human, non-Neanderthal species were detected from the teeth and a finger bone of Denisovan remains discovered in a Siberian cave. Fossil remains of Denisovans is very limited so we don’t have much data about them. The finger bone from the Denisovan was discovered in 2010 and is believed to have come from a female of the species that lived about 41Kya. It was found in the Denisova Cave in the Altai Mountains of Siberia. This same cave was also inhabited by Neanderthals and H. sapiens. Two teeth and a toe bone from Denisovans have also been discovered in the cave. Further, recently Denisovan remains were also found in Spain and that has left scientists scratching their heads as to how the Denisovans got to Spain. It appears that the Denisovans were more widespread than originally thought. It also appears that the Denisovans ranged from Spain, to Asia, to Southeast Asia.
So what is this mystery species that is neither Neanderthal nor human that the Denisovans were interbreeding with? If not human then the mystery species must be some primitive ape. Was it Gigantopithecus? I’ll talk more about this later.