London: Early humans, thought to be grunting cave-dwellers with little intelligence, were actually advanced mariners who were crossing the Mediterranean Sea from northern Africa at least 130,000 years ago, scientists say.
The re-think comes after a number of ancient tools found on the island of Crete were accurately dated -- and found to have been made by our early ancestors, called Homo Erectus.
Until now, the oldest known human settlements on Crete dated to around 9,000 years ago, the Daily Mail reported.
Traditional theories hold that early farming groups in southern Europe and the Middle East only began navigating vessels to Mediterranean islands at around that time.
But many of the Crete finds resemble hand axes fashioned in Africa about 800,000 years ago -- and a team has now been able to show that they are much older than first thought.
But it wasn't the latest carbon dating techniques, which have a limit of 50,000 years, that enabled scientists to date the tools.
Instead, geologists were able to use the island's unique rock formations to calculate when they were made. The island has been gradually pushed upwards out of the sea for millions of years -- creating a series of differentiated terraces along the coastline made up of ancient beach sands.
"We know that the tools are tens of meters above the
terrace we dated at 50,000 years old, so we know right off the
bat that they have to be at least that old," geologist Karl
Wegmann, of North Carolina State University, said.
The team was then able to work out the age of higher, older terraces, and calculated that the soil in which the tools were found was 130,000 years old.
The technique proved that Homo Erectus had inhabited the island by that time, and must have sailed across the Mediterranean to get there, the researchers said.
"The thing to me that really makes this unique and exciting is these other sister species maybe weren't entirely stupid like we portray them," Dr Wegmann said. "They were capable of really complex things."