All humans - according to biology- are from the same ancestors. We are all one. If we could accept this racial issues would become nonexistent
July 18, 2007 — Twenty years after it was popularized, the "Out of Africa" theory, which posits that modern humans originally came from Africa before spreading out in a global conquest, has received an emphatic boost, scientists said on Wednesday.
The "Out of Africa" scenario has been underpinned since 1987 by genetic studies based mainly on the rate of mutations in mitochondrial DNA, a genetic material inherited from the maternal line of ancestry.
They found that the farther a population is from Africa, the less genetic diversity that population has.
This was the result of a "bottleneck," or interbreeding among a smaller gene pool that occurred when migrating populations were temporarily reduced by war, disease or some other catastrophe.
The loss in genetic diversity was mirrored by a corresponding loss in diversity of skull characteristics.
The team tested the "multiple origins" theory on these two tools, and found "this just did not work," said fellow researcher Francois Balloux.
In 2000, Swedish research based on the molecular clock estimated that H. sapiens sapiens emerged about 121,500 to 221,500 years ago, and the migration out of Africa was about 52,000 years ago, give or take 27,500 years.