From discovermagazine.com: Did Humans Colonize the World by Boat?.
Jon Erlandson shakes out what appears to be a miniature evergreen from a clear ziplock bag and holds it out for me to examine. As one of the world’s leading authorities on ancient seafaring, he has devoted much of his career to hunting down hard evidence of ancient human migrations, searching for something most archaeologists long thought a figment: Ice Age mariners. On this drizzly late-fall afternoon in a lab at the University of Oregon in Eugene, the 53-year-old Erlandson looks as pleased as the father of a newborn — and perhaps just as anxious — as he shows me one of his latest prize finds.
The little "tree" in my hand is a dart head fashioned from creamy-brown chert and bristling with tiny barbs designed to lodge in the flesh of marine prey. Erlandson recently collected dozens of these little stemmed points from San Miguel Island, a scrap of land 27 miles off the coast of California. Radiocarbon dating of marine shells and burned twigs at the site shows that humans first landed on San Miguel at least 12,000 years ago, and the dart head in my hand holds clues to the ancestry of those seafarers. Archaeologists have recovered similar items scattered along the rim of the North Pacific, and some have even been found in coastal Peru and Chile. The oldest appeared 15,600 years ago in coastal Japan. To Erlandson, these miniature trees look like a trail left by mariners who voyaged along the stormy northern coasts of the Pacific Ocean from Japan to the Americas during the last Ice Age. "We haven’t published the evidence for this hypothesis yet, and I’m kind of nervous about it," he says. "But we are getting very close."
Until recently most researchers would have dismissed such talk of Ice Age mariners and coastal migrations. [continue]