The Aegean Islands have been isolated for over 450,000 years, yet evidence of activity, possibly by multiple species of early humans, is all over the place

By Ariel David

Could hominins predating the very evolution of sapiens, sail? It's been suggested before. Now a new study supports the case that supposedly primitive hominins made short sea journeys around the Mediterranean Sea, and populated the Aegean Islands at least half a million years ago. That is well before the much-vaunted Homo sapiens was even a twinkle in the eye of natural selection.

The question of when humans, or their ancestors, gained the cognitive and technical ability to cross the seas has long been the subject of debate. For a while we thought that Sapiens was the only member of the Homo family to have the ability to sail the oceans, with modern humans first reaching Australia around 50,000 years ago. But that paradigm has been crumbling in recent years in the face of evidence suggesting that early hominins were much more advanced than previously thought and did in fact leave clues that they traveled to lands completely surrounded by water.

There are two problems with figuring out whether hominins really took their first sea trips hundreds of thousands of years ago. Any rafts or canoes made of wood and organic matter have long decomposed. Also, because sea levels were lower during glacial periods, hominins are thought to have reached certain islands when they were connected by land bridges to the mainland. For example, it is believed that humans first reached America by walking over from Asia when the Bering Strait was connected by land (when exactly this crossing happened is a whole other can of worms).

However, there is growing evidence that several areas that were islands for hundreds of thousands or even millions of years were occupied by hominins, who must have braved the waves to get there. This is now argued to be the case with the Aegean Islands, an archipelago of hundreds of islands between Greece and Turkey, including favorite holiday destinations such as Crete, Mikonos and Santorini.

During the last half a million years there were five major glacial events and five warmer periods, explains George Ferentinos, emeritus professor of geology at the University of Patras, who led the study. During the coldest periods, the sea was more than 200 meters below its current level, Ferentinos and colleagues report. At these times, the Cyclades, the central group of islands in the Aegean, would be united into a single mega-island, the researchers found. But an island it would still remain.

During the entire 450,000 years, the closest Aegean Islands were still separated by 5 to 7 kilometers of water from the Greek or Turkish mainland in peak Ice Age conditions, Ferentinos says. This distance would increase to 40 kilometers during warmer periods, he says.

The key here is that, throughout the period, the closest islands always remained visible from the mainland, providing a tantalizing incentive to explore new territories.

I can see elephants from my cave

This doesn’t necessary mean they invented the boat just yet. Our distant ancestors (and others) could have island-hopped through the Aegean using primitive rafts or just by clinging to a tree log, Gkioni speculates. But why would they take on such a perilous journey?

One possibility is that they were following their lunch. Some researchers suspect that hominins first dispersed across the world simply because they were tracking herds of large animals – and possibly hunting them into extinction. Now, elephants are pretty good swimmers and it is known that a species of dwarf elephant survived in the Aegean until a few thousand years ago.

But elephants were also one of the favorite meals of prehistoric hominins, so it is possible that, as megafauna herds dwindled on the mainland, the early island-hoppers of the Aegean went looking for new hunting grounds, Gkioni says.

“All this means that these hominins already had advanced cognitive capabilities,” Gkioni tells Haaretz. “To cross over and colonize an island you need to have collaboration, a common language and complex communication.”

Given that different hominins often used the same stone tool technologies it is difficult to determine who exactly the first colonizers of the Aegean Islands were without finding any human remains. However, the most likely candidates would be Erectus or one of his descendants, such as Homo heidelbergensis, which mostly populated Europe, or Nesher Ramla Homo, a recently proposed Middle Pleistocene inhabitant of modern-day Israel and the Levant.