Washington, May 10 : A new study has suggested that the peopling of the Americas was a much slower and deliberate process, rather than a blitzkrieg movement.
Tom Dillehay, professor of anthropology at Vanderbilt University, Nashville, Tennessee, led the study.
Though evidence from an archaeological site in southern Chile confirms Monte Verde is the Americas earliest known settlement and is consistent with the idea that early human migration occurred along the Pacific Coast more than 14,000 years ago, the question remains about just how rapidly that migration occurred.
According to Dillehay, if all the early American groups were following a similar pattern of moving back and forth between inland and coastal areas, then the peopling of the Americas may not have been the blitzkrieg movement to the south that people have presumed, but a much slower and more deliberate process.
Most scholars now accept that people entered North America through the Bering Strait land bridge before 16,000 calendar years ago. It is not known whether people colonized the Americas by moving along the Pacific coast, through interior routes or both.
Researchers envision that coastal migration would have been a rapid process, but seaweed samples and gomphothere meat (meat from an extinct elephant-like animal that was widespread in the Americas 12-1.6 million years ago) found at Monte Verde may be signs of slower migration.
Although the site is located 50 miles from the Pacific coast and 10 miles from an inland marine bay to the south, Dillehay and the research team identified nine species of seaweed and marine algae found in hearths and other areas in the settlement.
The samples were directly dated between 14,220 to 13,980 years ago, 1,000 years earlier than other reliably dated human settlements in the Americas and indicate that early immigrants could have moved south along the shoreline exploiting familiar coastal resources to get much of their food.
The researchers also found a number of inland resources, including gomphothere meat. The finding suggests immigrants moved back and forth between the coast and inland areas.
"It takes time to adapt to these inland resources and then come back out to the coast. The other coastal sites that we have found also show inland contacts," said Dillehay.
Evidence to support the coastal migration theory is particularly hard to find because sea levels at the time were about 200 feet lower than today. As the sea level rose, it covered most of the early coastal settlements.
But the seaweed finding, one of the most significant, verifies the migrants' use of coastal resources, making it a likely path.