Summary timeline for the archaeology, hominin fossils and hominin DNA retrieved from the sediments at Denisova Cave. All age ranges are shown at the 95.4% confidence interval. Bert Roberts,Interesting paper by Zenobia Jacobs, Bo Li, Kieran O'Gorman and Richard Roberts all from the University of Wollongong in The Conversation: Fresh clues to the life and times of the Denisovans, a little-known ancient group of humans (31 January 2018) .
The Denisova site is interesting because it is the only known site so far for the Denisovan species of hominin, the only site where Denisovans and Neanderthals overlapped. The latest dating results are summarised this way.
The new studies show that hominins have occupied the site almost continuously through relatively warm and cold periods over the past 300,000 years, leaving behind stone tools and other artefacts in the cave deposits.
Fossils and DNA traces of Denisovans are found from at least 200,000 to 50,000 years ago, and those of Neanderthals from between 200,000 and 100,000 years ago. The girl with mixed ancestry reveals that the two groups of hominins met and interbred around 100,000 years ago.Both the Aborigines and Papuans have significant traces of Denisovan DNA suggesting that their ancestors met and mixed with the Denisovans on their journey to Sahul. An alternative but still less likely explanation is that the Denisovans had already reached Sahul at least in small numbers and the admixture occurred here.
I say this only because there is now an apparent tension that I do not understand between the archaeological dates and those generated by DNA analysis. The first presently suggests earliest occupation of perhaps 62,000 years ago based on archaeological dating, while the second suggests an out of Africa date for the Aborigines and Papuans of perhaps 51-72,000 years based on DNA modelling. There is still an overlap, but it has become too small for my comfort. .
I think that what is clear is that the new evidence is progressively changing our understanding of the human pattern of settlement in Eurasia and that this will necessarily change our understanding of Sahul's history.