Homo sapiens may have had several routes of dispersal across Asia in the Late Pleistocene

IMAGE: Illustrated dispersal routes from the results of the Least Cost Path analysis: The three routes from the "wet " simulations and the single route from the "dry " simulation are presented together... view more 

Credit: Li et al, 2019

Homo sapiens may have had a variety of routes to choose from while dispersing across Asia during the Late Pleistocene Epoch, according to a study released May 29, 2019 in the open-access journal PLOS ONE by Feng Li of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing and colleagues.
After leaving Africa, Homo sapiens dispersed across the Asian continent during the Late Pleistocene, but it isn't known exactly what routes our species followed. Most models assume that the Gobi Desert and Altai Mountain chains of North and Central Asia formed impassable barriers on the way to the east, so archaeological exploration has tended to neglect those regions in favor of seemingly more likely paths farther north and south.
In this study, Li and colleagues use Geographic Information Systems (GIS) software alongside archaeological and paleoclimate data to reconstruct the conditions of North and Central Asia over the Late Pleistocene and to identify possible routes of travel. Their data suggest that the desert and mountain regions were likely impassable during cold and dry glacial periods, but that during warmer and wetter interglacial times it would have been possible for human populations to traverse these regions via at least three routes following ancient lake and river systems.
The authors caution that these data do not demonstrate definite routes of dispersal and that more detailed models should be constructed to test these results. However, these models do identify specific routes that may be good candidates for future archaeological exploration. Understanding the timing and tempo of Homo sapiens dispersal across Asia will be crucial for determining how culture and technology spread and developed, as well as how our species interacted with our extinct cousins, the Neanderthals and Denisovans.
Roberts adds: "Our modelling of the available geographic and past climate data suggest that archaeologists and anthropologists should look for early human presence, migration, and interaction with other hominins in new parts of Asia that have been neglected as static voids. Given what we are increasingly discovering about the flexibility of our species, it would be of no surprise if we were to find early Homo sapiens in the middle of modern deserts or mountainous glacial sheets all across Asia. Indeed, it may be here that the key to our species' uniqueness lies".