Legion Troll
A fine upstanding poster

Modern humans evolved somewhere in Africa roughly 200,000 years ago. But how did our species go on to populate the rest of the globe?
Did humans flood out of Africa in a single diaspora, or did we trickle from the continent in waves spread out over tens of thousands of years? The question, one of the biggest in human evolution, has plagued scientists for decades.
Now they may have found an answer.
In a series of unprecedented genetic analyses published on Wednesday in the journal Nature, three separate teams of researchers conclude that all non-Africans today trace their ancestry to a single population emerging from Africa between 50,000 and 80,000 years ago.
http://www.nytimes.com/2016/09/22/science/ancient-dna-human-history.html?_r=0