UK Daily Mail 
March 27, 2012
People moved between Africa and Europe long before recorded history – and the migrations might have been driven by Europeans moving south to ‘weather’ ice ages.
The genetic traces of long-forgotten migrations from Africa to Europe live on in Europeans today.
A third of the genetic traces of sub-Saharan lineages in today’s Europe come from prehistory.
Researchers think that Europeans ‘pushed south’ by glaciers might have met with populations from sub-Saharan Africa.
People moved between the continents as early as 11,000 years ago.
Geneticists used mitochondrial DNA to look for the traces of ancient migrations.