Ottawa, March 17 : A team of U.S. researchers has proposed a new "working model" for when and how humans came to the New World, suggesting that ancient seafarers, traveling by boat along the ice-fringed British Columbia coast, launched the peopling of the Americas about 15,000 years ago.
According to a report from Canwest News Service, a team led by Texas A and M University anthropologist Ted Goebel has proposed the theory.
It challenges a long-held view that the earliest newcomers to North America were big-game hunters who arrived about 12,000 years ago from Siberia, pursuing mammoths and other ice age prey across the dried-up Bering Strait to Alaska and the Yukon. They then eventually spread south to warmer parts of North America through an ice-free corridor in present-day Alberta.
It appears, the U.S. researchers concluded, that both streams of migration occurred.
But their study tilts the crucial matter of identifying the "first" wave of North Americans toward the coastal migrants, and sets the date of that arrival back by at least 2,000 years, to 13,000 BC or earlier.
"If this is the time of colonization, geological data from Western Canada suggest that humans dispersed along the recently de-glaciated Pacific coastline," said Goebel.
According to the study, the first Americans used boats, and the coastal corridor would have been the likely route of passage, since the interior corridor appears to have remained closed for at least another 1,000 years.
The earlier maritime migrants are thought to have plied the coastal waters of the North Pacific in sealskin boats, moving in small groups over many generations from their traditional homelands in the Japanese islands or elsewhere.
"Once humans reached the Pacific Northwest, they could have continued their spread southward along the coast to Chile, as well as eastward," it added.
This entry route would help explain the growing number of archeological sites dating from before 13,000 years ago, which the previous prevailing theory of an overland migration couldn't account for.
Presumed archeological traces left by the New World pioneers along B.C.'s coast would have been submerged by the rising Pacific Ocean about 10,000 years ago, after the final retreat of the glaciers. That's why Canadian scientists have been scouring raised sea caves on Vancouver Island and elsewhere in B.C., looking for direct proof that this earlier coastal migration took place.
Those caves, it's believed, were among the earliest ice-free refuges after the glaciers retreated, and later escaped flooding from the rising Pacific. Researchers believe they harbour evidence of a prehistoric ecosystem - and potentially even human artifacts.