Radiocarbon tests of carbonized plant remains where artifacts were unearthed last May along the Savannah River in Allendale County by University of South Carolina archaeologist Dr. Albert Goodyear indicate that the sediments containing these artifacts are at least 50,000 years old, meaning that humans inhabited North American long before the last ice age.The findings are significant because they suggest that humans inhabited North America well before the last ice age more than 20,000 years ago, a potentially explosive revelation in American archaeology. [...]
"The dates could actually be older," Goodyear says. "Fifty-thousand should be a minimum age since there may be little detectable activity left."
UPDATE: Here's a little more from CNN. Excerpt:
If true, the find represents a revelation for scientists studying how humans migrated to the Americas.[...] "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. [...]
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."
UPDATE II: Nice overview from the Christian Science Monitor.