Avast, ye scurvy Homo erectus! Recent archaeological finds from Crete show that the first seafaring humans set sail for parts unknown more than 10 times earlier than previously thought.
So instead of settlements on the Greek island around 10,000 years ago, we now have evidence of human activity there at least 125,000 years ago, and that’s the low end of the estimate.
Upwardly Mobile Island
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. A series of marine terraces, or beaches, formed as Crete rose and global sea levels fluctuated due to growth and melting of continental ice sheets.
Crete’s continual rise guaranteed that the beaches—and the items left there by early settlers—were preserved. Archaeologists from Greece and the United States who found stone tools of the sort routinely used by Homo erectus on one of those beaches determined how long ago the tools were left behind by matching the beach terraces to known sea levels and then extrapolating the age.
NC State geologist Dr. Karl Wegmann put the tools in 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,” he says. “From there, we knew that the age of the beaches increased with time. Basically, the formula is elevation divided by time.”
Too Far to Swim
Now the scientists had proof that people were on the island much earlier than previously thought. But how did early humans get to Crete? There wasn’t a land route available at the time, and the shortest distance over water was about six miles—probably a bit too far to swim.
“They had to have used some sort of boat, although we will probably never find preserved evidence of one,” Wegmann says.
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.”