http://www.cnn.com/2004/TECH/science/11/17/carolina.dig/index.html Scientist: Man in Americas earlier than thought
Archaeologists put humans in North America 50,000 years ago
By Marsha Walton and Michael Coren
CNNWednesday, November 17, 2004 Posted: 2:17 PM EST (1917 GMT)
(CNN) -- Archaeologists say a site in South Carolina may rewrite the history of how the Americas were settled by pushing back the date of human settlement thousands of years.
An archaeologist from the University of South Carolina today announced radiocarbon tests that dated the first human settlement in North America to 50,000 years ago -- at least 25,000 years before other known human sites on the continent.
"Topper is the oldest radiocarbon dated site in North America," said Albert Goodyear of the University of South Carolina Institute of Archaeology and Anthropology.
If true, the find represents a revelation for scientists studying how humans migrated to the Americas.
Most scientists believe humans' first ventures to the New World were across a land bridge from present-day Russia to Alaska about 13,000 years ago. The new evidence suggests humans crossed the land bridge much earlier -- possibly during an ice age -- to the Americas and rapidly colonized the two continents.
"It poses some real problems trying to explain how you have people (arriving) in Central Asia almost at the same time as people in the Eastern United States," said Theodore Schurr, anthropology professor at the University of Pennsylvania and a curator at the school's museum.
"You almost have to hope for instantaneous expansion...We're talking about a very rapid movement of people around the globe."
Schurr said that conclusive evidence of stone tools similar to those in the old world and uncontaminated radiocarbon dating samples would be needed to verify the findings as old as 50,000 years ago.
"If dating is confirmed, then it really does have a significant impact on our previous understanding of New World colonization," he said.
Modern humans, or homo sapiens, emerged between 60,000 and 80,000 years ago in Africa. Modern humans quickly fanned out to Australia and Central Asia about 50,000 years ago and arrived in Europe only about 40,000 years ago. It was thought until recently that no humans arrived in the New World until about 13,000 years ago. Archaic hominids like australopithecines and Neanderthals have never been found in the New World.
University of Wisconsin at Madison professor, geologist Thomas Stafford, said that the shocking results would shake scientists' theories about human development, but would lead to new ideas.
"It's a slow process," he said. "You have preconceived ideas...Until someone rocks the boat, you really don't think about something new."
Goodyear plans to publish his work in a peer-reviewed scientific journal next year which is the standard method by which scientists announce their findings
Until research is peer-reviewed, objective experts in the field have not necessarily had an opportunity to evaluate a scientist's methods, or weigh in on the validity of his conclusions.
Archaeologists will meet in October of 2005 for a conference in Columbia, South Carolina, to discuss the earliest inhabitants of North America, including a visit to the Topper Site.
Goodyear has been excavating the Topper dig site along the Savannah River since the 1980s. He recovered artifacts and tools last May that are expected to push the date of colonization back before most of the earliest known settlements on the continent.
Goodyear dug four meters (13 feet) deeper than the soil layer containing the earliest North American people, known as the Clovis culture, and began uncovering a plethora of tools.
Scientists and volunteers at the site in Allendale have unearthed hundreds of implements, many stone chisels and tools likely used to skin hides, butcher meat, carve antlers, wood and possibly ivory. The tools were fashioned from a substance called chert, a flint like stone that is found in the region.
These discoveries could push that date back thousands -- maybe even tens of thousands -- of years and demand a new explanation for how the Americas were first settled.
Since the 1930s, archaeologists have generally believed North America was settled by hunters following large game over a land bridge from Russia during the last major ice age about 13,000 years ago.
"That had been repeated so many times in textbooks and lectures it became part of the common lore," said Dennis Stanford, curator of archeology at the Smithsonian Institution. "People forgot it was only an unproven hypothesis."
Land-bridge assumption challenged
A growing body of evidence is prompting some scientists to challenge that assumption.
A scattering of sites from South America to Wisconsin have detected human presence before 13,000 years ago -- or the first Clovis sites -- since the first groundbreaking discovery of human artifacts in a cave near Clovis, New Mexico, in 1936.
These discoveries have led archaeologists to support alternative theories -- such as settlement by sea -- for the Americas.
Goodyear and his colleagues began their dig at the Topper Site in the early 1980s with a goal of finding out more about the Clovis people, long thought to be the earliest people to settle the Americas.
Goodyear thought that because of the resources available along the Savannah River and the moderate climate it would be a good place to look for even earlier human settlers than the Clovis people.