Human ancestors went from Africa to the world

If the Southern Tier was the main route for humans out of Africa, then Ethiopians and Eurasians should be genetically more similar. Instead, the researchers found that the Egyptians were genetically more similar to Eurasians, suggesting that the Northern Route was the main route for humans out of Africa. The researchers estimate that the genetic separation of Eurasians from Egyptians should have occurred 55,000 years ago, 65,000 years ago from Ethiopians, and 75,000 years ago from West Africans.

The paper's lead author, Luca Pagani, a molecular anthropologist at the Sanger Institute in Cambridge, said: "One of the most exciting aspects of the findings is that we have revealed a single event in the evolutionary journey of all Eurasians. This discovery has the potential to help improve the deeper understanding of the biological history of billions of people."

The Northern Line as the main route out of Africa is supported by other facts - all people outside of Africa carried Neanderthal genes, and Neanderthals were living in the Eastern Mediterranean along the Northern Line at the time. The new discovery also coincides with the recent discovery of a modern human fossil in the area of Israel close to the Northern Line, which is about 55,000 years old.

While there is genetic and archaeological evidence that some human ancestors did travel out of Africa from the Southern Tier, perhaps these people did not travel further than Arabia or they did not leave genetic traces in modern Eurasians. Pagani said that in the future, scientists will study whether the people who chose the Southern Tier left genetic traces in modern-day Australians.