Researchers extracted DNA from a 4,500-year-old skull that was discovered in the highlands of Ethiopia.
A comparison with genetic material from today’s Africans reveals how our ancient ancestors mixed and moved around the continents.
The findings, published in the journal Science, suggests that about 3,000 years ago there was a huge wave of migration from Eurasia into Africa.
This has left a genetic legacy, and the scientists believe up to 25% of the DNA of modern Africans can be traced back to this event.
“Every single population for which we have data in Africa has a sizeable component of Eurasian ancestry,” said Dr Andrea Manica, from the University of Cambridge, who carried out the research.
Ancient genomes have been sequenced from around the world, but Africa has proved difficult because hot and humid conditions can destroy fragile DNA.
However, the 4,500-year-old remains of this hunter gatherer, known as Mota man, were found in a cave and were well preserved.
Importantly, a bone that is situated just below the ear, called the petrous, was intact.