Pirates of the Paleolithic
Avast, ye scurvy Homo erectus! Recent archaeological finds from Crete show that the first seafaring humans set sail for parts unknown – or maybe parts barely visible to the naked eye – more than 10 times earlier than previously thought.
So instead of man settling the Greek island around 10,000 years ago, we now have evidence of human activity there from at least 125,000 years ago, and that’s the low end of the estimate.
How do we know? Because Crete, unlike other islands in the Aegean, has been rising from the sea at a rate of about one millimeter per year. As Crete rose, and global sea levels fluctuated due to growth and melting of continental ice sheets, a series of marine terraces, or beaches, formed on the island. Crete’s continual vertical movement guaranteed that the beaches – and the items left on them by early settlers – were preserved. So when archaeologists from Greece and the United States found stone tools of the sort routinely used by Homo erectus on one of those beaches, they determined how long ago these tools were left behind by matching the series of beaches to known sea levels, and then extrapolating the age.
NC State geologist Dr. Karl Wegmann was asked to put the tools in just this geological context. “We started with the baseline radiocarbon dating, using spiny oyster shells, which confirmed that the lowest of these beach terraces was at least 45 – 50,000 years old,” Wegmann says. “That’s the upper limit from the radiocarbon. From there, we knew that the age of the beaches increased with time. Basically, the formula is elevation divided by time.”
Now the scientists had proof that people were on Crete much earlier than they thought. But how did early man get there? There wasn’t a land route available at the time, and the shortest distance over water was about 10 kilometers or around six miles – probably a bit too far to swim. “They had to have used some sort of boat,” says Wegmann, “although we will probably never find preserved evidence of one.”
For Wegmann, the implications go beyond just dating the geology surrounding the civilization. “We all have this idea that early man wasn’t terribly smart,” he says. “This finding shows otherwise – that our ancestors were smart enough to build boats, and adventurous enough to want to use them.”