Ancient people from sub-Saharan Africa may have crossed the Strait of Gibraltar into current-day Spain 1300 years earlier than we thought. A genetic analysis of human samples is the first evidence of such a migration in prehistoric times.
     "We are finding that the Strait of Gibraltar was not a barrier for human contact, migration or gene flow between Africa and Spain," says Gloria Maria Gonzalez Fortes at the University of Ferrara in Italy.
     Previous research suggested that African genes flowed to Spain and Portugal during the Islamic occupation of Spain, which started in the 8th century and lasted about 800 years. "We found that it may be from a time much earlier than that," says Gonzalez Fortes.
     She and her team analysed the DNA from 17 ancient people found on the Iberian Peninsula, from the south of Spain to the north of Portugal, carbon dated to 3000 to 4500 years old. They compared their mitochondrial DNA to archaeological samples from South Africa. They found similarities between the samples from Iberia and Africa, with more African genetic markers in the Spanish samples. This fits with the archaeological record, which shows similarities in tools and pottery decoration made by North African people and those who populated Andalusia in southern Spain.
     "4000 years ago, people were already building ships and sailing, so why wouldn't they cross the Strait of Gibraltar? You can see the coast of Africa from the coast of Spain. The sea there is very dangerous, so people were sceptical about this, but it's likely this was the path they took," says Gonzalez Fortes. She says their data show that this migration happened at least 4000 years ago, but it may have happened even earlier.

Edited from New Scientist (23 January 2019)