The Oldest Denisovan Fossils To Date
Five new hominin fossils from the Denisova Cave are 200,000 years old
A new paper1 in Nature Ecology and Evolution has been published documenting the discovery of five new hominin fossils from the famed Denisova Cave, in southern Siberia as well as their associated stone tools and faunal remains. This cave is in the Altai mountains and came to fame approximately 11 years ago when a pinky bone was discovered2. At that time, genetic sequencing of ancient DNA revealed a new, previously unknown group of humans that we now know as Denisovans3. It has been hard to identify definitive human remains from comparative anatomy alone as there are hundreds of thousands of small bone fragments of animals as well in this cave that muddle the search.
During the last four years, the team responsible for the above findings has been able to extract and analyze ancient DNA and proteins from over 4,000 bone fragments in this cave. They were able to find five new human fossils based upon collagen results that matched the peptides profiles of humans. This methodology is called ZooMS, or zooarchaeology by Mass Spectroscopy4. This is the only means by which these scientists have been able to identify human remains in this site from the thousands of remains as over 95% of them are too fragmented. Below is a photo of their sample. This has been a remarkable breakthrough.
Four of the five remains contained enough ancient DNA to reconstruct mitochondrial DNA. Three of them were Denisovan mtDNA and one Neanderthal. This makes the new Denisovan bones in this study some of the oldest fossils to be genetically sequenced, which is another accomplishment in itself.
Interestingly enough, the remains were surrounded by stone tools and refuse that gave some potential archaeological context to these individuals. We know that these people had a fully lithic tradition and hunted big game like bison, dear, gazelle, antelope, and even woolly rhinoceros around 200,000 years ago. This is the first direct evidence that the Denisovans were the maker of the tools they were found alongside. Approximately, 130,000 to 150-000 years ago, Neanderthals appeared at this site and likely admixed with this population of Denisovans both genetically and culturally. But before that, it was only Denisovans and their cultural remains.
In summary, this is a hallmark paper in that it documents the application of using ZooMS to identify remains that were not able to be identified by previously conventional remains. Furthermore, these are the oldest Denisovan remains found to date and they have associated archaeological context that gives us insight into their technology and environment.
Brown, S., Massilani, D., Kozlikin, M.B. et al. The earliest Denisovans and their cultural adaptation. Nat Ecol Evol (2021). https://doi.org/10.1038/s41559-021-01581-2
Reich, D., Green, R., Kircher, M. et al. Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature 468, 1053–1060 (2010). https://doi.org/10.1038/nature09710
Krause J, Fu Q, Good JM, Viola B, Shunkov MV, Derevianko AP, Pääbo S. The complete mitochondrial DNA genome of an unknown hominin from southern Siberia. Nature. 2010 Apr 8;464(7290):894-7. doi: 10.1038/nature08976. Epub 2010 Mar 24. PMID: 20336068.