Scientist: Man in Americas earlier than thought
Archaeologists put humans in North America 50,000 years ago
By Marsha Walton and Michael Coren
(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.
But their interpretation is already igniting controversy among scientists.
An archaeologist from the University of South Carolina on Wednesday 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.
Many scientists thought humans first ventured into the New World across a land bridge from present-day Russia into Alaska about 13,000 years ago.
This new discovery suggests humans may have crossed the land bridge into the Americas much earlier -- possibly during an ice age -- 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 Asia and uncontaminated radiocarbon dating samples are needed to verify that the Topper site is actually 50,000 years old.
"If dating is confirmed, then it really does have a significant impact on our previous understanding of New World colonization," he said.
But not all scientists are convinced that what Goodyear found is a human settlement.
"He has a very old geologic formation, but I can't agree with his interpretation of those stones being man-made," said Michael Collins of the Texas Archeological Research Lab at the University of Texas at Austin. Collins disputes that the stone shards at the site show signs of human manipulation.
But whether the Topper site proves valid, Collins said most archeologists now believe people settled in America before 13,000 years ago, refuting a theory that has held sway for 75 years.
Since the 1930s, archaeologists generally believed North America was settled by hunters following large game over the land bridge 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."
A growing body of evidence has prompted scientists to challenge that assumption.
A scattering of sites from South America to Oklahoma have found evidence of a human presence before 13,000 years ago -- or the first Clovis sites -- since the discovery of human artifacts in a cave near Clovis, New Mexico, in 1936.
These discoveries are leading archaeologists to support alternative theories -- such as settlement by sea -- for the Americas.
Worldwide, ideas about human origins have rapidly changed with groundbreaking discoveries that humans ranged farther and earlier than once believed. Fossils in Indonesia nearly 2 million years old suggest that protohumans left their African homeland hundreds of thousands of years earlier than first theorized.
Modern humans, or homo sapiens, most likely emerged between 60,000 and 80,000 years ago in Africa. They quickly fanned out to Australia and Central Asia about 50,000 years ago and arrived in Europe only about 40,000 years ago. Ancestral humans -- hominids like australopithecines and Neanderthals -- have never been found in the New World.
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, experts in the field may not have an opportunity to evaluate the 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 many of the artifacts and tools last May.
Goodyear dug four meters (13 feet) deeper than the soil layer containing the earliest North American people and began uncovering a plethora of tools. Until recently, many archeologists did not dig below where Clovis artifacts were expected to be found.
Scientists and volunteers at the site in Allendale have unearthed hundreds of possible implements, many appearing to be stone chisels and tools that could have been used to skin hides, butcher meat or carve antlers, wood and ivory. The tools were fashioned from a substance called chert, a flint-like stone found in the region.
Goodyear and his colleagues began their dig at the Topper Site in the early 1980s with the goal of finding out more about the Clovis people. Goodyear thought it would also be a good place to look for earlier human settlers because of the resources along the Savannah River and the moderate climate.