Humans Travelled the Seas 450,000 Years Ago, According to New Maps of Ancient Shorelines

Ancient humans may have been navigating the world’s seas as far back as nearly a half-million years ago, according to a new analysis of the ancient shorelines of the Mediterranean Sea.

Evidence of human habitation on the Aegean Islands that are part of modern-day Greece come in the form of fossils and stone tools, with similar artifacts found in Crete, Greece and Turkey fashioned in a style associated with Homo erectus dating to 1.2 million years ago. The habitation of the Aegean Islands by ancient humans was assumed to have taken place during earlier ice ages, when much of the planet’s water was locked up in massive glaciers, exposing land bridges to the now-isolated islands that allowed early populations to migrate there by foot.

However, a new analysis of the ancient shorelines of the Aegean Sea, conducted at Greece’s University of Patras, shows that water levels in the Mediterranean never dropped far enough to expose enough of the seabed to allow someone to walk there, despite being as low as 225 meters (738 feet) than what is present today.

The research team reconstructed the region’s ancient shorelines back to 450,000 years ago by surveying ancient river deltas and land subsidence caused by tectonic activity; they found that although local sea levels were nearly two and a half football fields lower than they are today, the land mass that would have encompassed today’s islands of Lesbos, Milos, and Naxos, where many of these ancient tools were found, was still separated from the mainland by several kilometers of open water, a distance too far for a human to comfortably swim, let alone walk.

The alternative to walking to these still-isolated islands is to sail there, using a water craft of some sort. Unfortunately, the materials that would be used to fashion such a vehicle, such as wood, bamboo or reeds, are unlikely to have survived intact over such a long period of time—the oldest carved wood artifacts only date back to a fraction of the span of time being considered here—so it is unlikely that a primitive canoe or raft that might have ferried the ancient Aegean populations to their island homes will be found.

This is also not the first evidence that ancient humans have answered the call of the sea: there is evidence that ancient mariners were navigating the waters surrounding Indonesia and the Philippines as early as 700,000 years ago, hundreds of thousands of years before Homo sapiens appeared on the scene. The idea that humans may have been crossing the waters of the Mediterranean so early in our history also opens the possibility that migrations from Africa may have also taken place at the western end of the continent, and not just through the Levant in the east.

According to the study paper text, if these “archaic hominins were able to cross the Aegean Sea, they would also have been capable of crossing the Gibraltar Straits,” upending the notion that “the peopling of southwestern Europe from the Sinai Peninsula and Levantine plains” was the only possible way that ancient peoples had spread northward.