Science has published a new paper today looking at the peopling of Eurasia. The results of the paper challenge the single Out of Africa model by ultimately stating that it cannot fully explain the origins of modern humans.
The authors primarily state that Homo sapiens spread to the extremities of Asia as well as Near Oceania, much earlier than we previously thought. The estimate there were multiple dispersal events out of Africa, beginning as early as 120,000 years ago by bring together multiple lines of evidence. For example, H. sapiens remains dated to between 70,000 and 120,000 years ago have been found at multiple sites in southern and central China. And 60,000 year old Southeast Asian and Australia mean they got there much earlier.
On the other hand there are compelling recent studies that pin down that all present-day non-African populations branched off from a single ancestral population in Africa approximately 60,000 years ago. Integrating both theories there are likely multiple, smaller dispersal of humans out of Africa beginning as early as 120,000 years ago, followed by a major dispersal 60,000 years ago since human species like Neanderthals and Denisovans interbred with modern humans. In all, it is now clear that several human species overlapped in time and space in Asia, and they certainly had many instances of interaction.
In light of these new discoveries, our understanding of human movements across the Old World has become much more complex, and there are still many questions left open.