The traditional view
The traditional ‘Out of Africa’ model suggests that modern humans evolved in Africa and then left in a single wave around 60,000 years ago.
The model often holds once modern humans left the continent, a brief period of interbreeding with Neanderthals occurred.
This explains why individuals of European and Asian heritage today still have ancient human DNA.
There are many theories as to what drove the downfall of the Neanderthals.
Experts have suggested that early humans may have carried tropical diseases with them from Africa that wiped out their ape-like cousins.
Others claim that plummeting temperatures due to climate change wiped out the Neanderthals.
The predominant theory is that early humans killed off the Neanderthal through competition for food and habitat.
How the story is changing in light of new research
Recent findings suggest that the ‘Out of Africa’ theory does not tell the full story of our ancestors.
Instead, multiple, smaller movements of humans out of Africa beginning 120,000 years ago were then followed by a major migration 60,000 years ago.
Most of our DNA is made up of this latter group, but the earlier migrations, also known as ‘dispersals’, are still evident.
This explains recent studies of early human remains which have been found in the far reaches of Asia dating back further than 60,000 years.
For example, H. sapiens remains have been found at multiple sites in southern and central China that have been dated to between 70,000 and 120,000 years ago.
Other recent finds show that modern humans reached Southeast Asia and Australia prior to 60,000 years ago.
Based on these studies, humans could not have come in a single wave from Africa around this time, studies have found.
Instead, the origin of man suggests that modern humans developed in multiple regions around the world.
The theory claims that groups of a pre-human ancestors made their way out of Africa and spread across parts of Europe and the Middle East.
From here the species developed into modern humans in several places at once.
The argument is by a new analysis of a 260,000-year-old skull found in Dali County in China’s Shaanxi Province.
The skull suggests that early humans migrated to Asia, where they evolved modern human traits and then moved back to Africa.