The more we learn about the extinct predecessors to modern humans called the Denisovans (Homo Denisova), the more amazing they become. First discovered in the Siberian Denisova Cave, their remains have now been positively identified in the Baishiya Karst Cave in Tibet, showing this cold weather species didn’t mind heights or thin air either. Even more interesting, the proof did not come from the piece of jawbone found in the cave.
“We detected ancient human fragments that matched mitochondrial DNA associated with Denisovans in four different layers of sediment deposited around 100,000 and 60,000 years ago.”
In a new paper published in the journal Science, Bo Li, co-author and dating specialist from the University of Wollongong in Australia, reveals that mitochondrial DNA was found in multiple layers of the soil in Baishiya Karst Cave, indicating the Denisovans had lived there for quite a while. An international team, including archaeologists, geologists and geneticists from China, Germany, the US and Australia, found charcoal from fires, bones from rhinos and hyenas, and over 1,000 stone tools dating from 190,000 to 45,000 years ago. Mitochondrial DNA is inherited from the mother and can tell who the Denisovan was related to on the maternal side. That’s where the find yielded another surprise.
“Interestingly, we found that the hominin DNA from 60,000 years ago share the closest genetic relationship to the Denisova 3 and 4 specimens sampled from Denisova Cave [in Siberia]. In contrast, the DNA dating to 100,000 years ago show evidence that those Denisovans separated earlier from the lineage leading to Denisova 3 and 4.”
Li tells Cosmos how the different layers yielded different lineages from the Denisovans in Siberia and showed how long they lived there and how often they moved around … In this case, a long way from Denisova cave and 2 miles above sea level. Furthermore, the age of the tools indicate they may have lived there even longer. Sediment possibly from as late as 30,000 years ago appears to have unconfirmed mitochondrial DNA, making it possible that the Denisovans could have share the cave with early modern humans, who first appeared in Tibet about 40,000 years ago.
While is the first confirmed evidence of Denisovan DNA in Tibet, it’s no secret that they got around and highly likely they mated with humans. There is evidence of Denisovan DNA in modern humans ranging from southeast Asia to China and Mongolia to Australia and Papua New Guinea. However, so little physical evidence of them has been found that virtually nothing of their lives is known, including when and why they disappeared, and what made them so darned sexually attractive to humans and Neanderthals.
That, as always, means more studies.