New research has found that the first people to make the journey from Africa to Europe may have crossed the Strait of Gibraltar some 4,000 years ago.
Scientists from the Royal Society analysed DNA from 17 ancient people found on the Iberian Peninsula, from the south of Spain to the north of Portugal.
History suggests people first came into Spain in the 8th century during the Moorish invasion, but this evidence points to migration across the Strait some 1,300 years earlier.
A genetic analysis of human samples is the first potential evidence of such a migration in prehistoric times.
Gloria Maria Gonzalez Fortes, from the University of Ferrara in Italy, spoke to Today on BBC’s Radio 4.
She said: “What we found in the samples from the south that were dated around 4,000 before present, we found a signal of African gene flow in the samples.”
“This is the first time that we found ancient humans in prehistoric Europe having gene flow from Africa.”
Ms Gonzalez Fortes believes that these people found an alternative route into Europe using boats to cross the Strait of Gibraltar.
This differs from the other migration from the time, which was primarily from the east to Western Europe.
Ms Gonzalez Fortes said people were already building ships some 4,000 years ago, so there is nothing to suggest they could not cross the Strait of Gibraltar.
But the findings were viewed with some scepticism by Gibraltar Museum Director Professor Clive Finlayson.
Mr Finlayson said the research provided “flimsy evidence” which suggests modern humans arrived in Eurasia before Neanderthals were extinct.
“There is no evidence that the modern humans crossed the Strait of Gibraltar to arrive in Eurasia,” he said.
“There is no new material in their research to suggest this, just a date.”