Icame across an interesting map while browsing the Internet, it shows the habitats where Denisovans and Neanderthals could have lived in Eurasia. Mind you, habitats or ecological regions suitable for them, which does not necessarily mean that they lived in this whole territory. It also found overlapping areas where both populations could have met, and exchanged genes.
The paper was published in 2023: Jiaoyang Ruan et al., Climate shifts orchestrated hominin interbreeding events across Eurasia. Science 381, 699-704 (2023). DOI:10.1126/science.add4459.
Denisovans and Neanderthals coexisted in Eurasia from around 400 ky ago to 30 ky ago. They met and mixed several times. This paper looked into the climate and how it altered their habitat forcing them to move east, west, north and south as it worsened or improved during the Ice Ages.
The paper points out the different enviornments each group lived in: "Both Neanderthals and Denisovans are simulated to have lived primarily in environments characterized by annual temperature, precipitation, and NPP of ~−10° to 20°C, ~500 to 1300 mm/year, and ~200 to 800 g of carbon per square meter per year, respectively. Yet, compared to Neanderthals, Denisovans were present in hot and humid climates, which points to a comparatively wider niche space. Whereas Neanderthals were more abundant in temperate forests, Denisovans were present in both boreal forest and tundra." Denisovans lived in Southeast Asia, but fossil preservation in that area is poor, so no remains have been found, but there are genetic markers of Denisovans in the modern humans living in that region, the Phillipines and Papua New Guinea.
During the marine isotope stage (MIS) 5 around 135-105 kya, the Neanderthals spread into Northeastern and Central Europe, and further east into Southern Siberia. During the cold glacial maximum periods, they retreatedinto refugia in Southern Europe and around the north of the Black Sea. The authors suggest that these differnt habitats during the glaical and interglacial periods can explain the divergence of Neanderthal haplogroups, and their split (See my post on Western and Eastern Neanderthals Were Very Divergent).
Regarding Denisovans, the paper finds that due "to glacial cooling, Denisovan habitats vanish in Scandinavia, mildly increase in its core areas from eastern Europe to Siberia, and show massive fragmentation in Asia."
Where did they interbreed?
In a previous post, I wondered where did Denisovans and Neanderthals admix, Ruan et al. answer that question: Both species overlapped for around 400,000 years and there were hotspots like the Altai region where Denisova cave is found, occupied by Neanderthals and Denisovans (yellow star in map above). The authors find that there were six interbreeding episodes between the two groups: "the five younger events cluster during the warm MIS 5, whereas the oldest event, although with considerable dating uncertainty, occurs in the cooler MIS 6. Because some of these events occurred thousands of years earlier than the fossil dates, they could have happened in places far away from the places where the specimens were found. Our simulation of Neanderthal-Denisovan overlap suggests that these MIS 5 interbreeding events took place in central-southern Siberia... By contrast, the MIS 6 event likely happened in eastern Europe."
They note that there was "bidirectional gene flow" between both groups in Siberia. And that European Neanderthals don't have signs of admixture suggesting the Denisovans didn't mingle with them in Europe, however, they also point out that "large-sample genetic analyses have recently revealed Denisovan ancestry in modern European populations in France and in Iceland, which suggests the possibility for more widespread and prevalent interbreeding than previously thought. These results are consistent with our model simulations, which indicate the presence of suitable Denisovan habitats in Europe under optimal orbital conditions" It isn't clear if they suggest that Denisovans intereacted with modern humans in Europe, or with Neanderthals who later admixed with modern humans. Another option is that Eastern Siberian modern humans picked up their Denisovan genes there, and then moved into Europe later, carrying them with them.
I did find interesting the extended Neanderthal habitat, reaching into Central, Western, and Eastern Africa, India, Korea, Eastern China, Southern Mongolia, Myanmar, Saudi Arabia, Yemen, Morocco. Not so long ago, Neanderthals had been confined to Western Europe and the Middle East. Now we see them spread across Eurasia. This has many interesting implications.
The paper also included a map with sites where Denisovan and Neanderthal remains have been found the caption reads: "Neanderthal and Denisovan locations and their corresponding climate and biome conditions. (A) Hominin fossil, archaeological, and genetic data compiled for HSMs; candidate Denisovans (dashed circle)". I reproduced it below.
The lonely brown circle on the right side of the map, is the easternmost Neanderthal outpost in Eastern Asia (in the map above) is Jinsitai Cave, North China. We will look into it in my next post.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2026 by Austin Whittall ©
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