Clovis not first Americans, study says

Jim Erickson, Rocky Mountain News

Friday, February 23, 2007

A Colorado geochemist and his Texas colleague say they have dealt the mortal blow to Clovis First, the long-held idea that the first Americans were spear-toting hunters who crossed into an uninhabited continent from Asia.

For decades, schoolchildren were taught that small bands of hide-clad hunters walked into a virgin world over a "land bridge" that linked Siberia to Alaska during the last ice age, about 13,600 years ago.

They quickly dispersed across North America, slaughtering mammoths with a new and highly efficient stone weapon: the Clovis spear point. Clovis hunters and their descendants then rapidly spread through Central America and to the southernmost tip of South America, according to the Clovis First scenario.

But evidence for pre-Clovis occupation of the Americas has been mounting for years at archaeological sites from Wisconsin and Pennsylvania to Chile.

'Final nail' in Clovis coffin

Now Colorado's Thomas Stafford Jr. and Michael Waters of Texas A&M University report findings that Waters says "puts the final nail in the coffin of the Clovis First model."

New radiocarbon dates from Clovis-site bone, ivory and seeds show that the hunters arrived nearly 500 years later than researchers had thought, at a time when unrelated peoples already lived in North and South America, the researchers conclude.

And it now appears that the Clovis culture bloomed and vanished in just two centuries. It seems "humanly impossible" that a group of hunters and their descendants could have spread across the Americas in such a short time span, Stafford said.

Perhaps it makes more sense to think of "Clovis" as a technological advance - a new and super-lethal type of spear point - rather than a group of nomadic hunters, Stafford said. Maybe the innovative Clovis weaponry spread like wildfire through existing populations of early Americans, he said.

"Clovis is a technology that moved into a place that was already populated," he said. "That seems more likely to me."

Not so fast, others say

The research is reported in today's edition of Science.

"This is an extremely significant result," said Kenneth Tankersley, a Northern Kentucky University anthropologist.

"This idea of a single group of people crossing the Bering (Sea) land bridge at a particular period in time - which has stood for close to a century - has now been shown beyond all reasonable doubt not to be true," he said.

Denver archaeologist Steve Holen said the new findings are "quite important" but called Waters' "final nail" comment an overstatement.

"The majority of archaeologists who study the early peopling of the Americas already agree that there were people in the Americas before Clovis," said Holen, curator of archaeology at the Denver Museum of Nature & Science.

The Clovis culture was named for distinctive stone projectile points found with mammoth remains near Clovis, N.M., in 1933. The tapered points have scooped-out vertical channels, called flutes, on both faces.

Technology aids research

Stafford, who works in Golden, is an authority on the extraction of collagen, the protein used in radiocarbon dating, from fossil remains. Stafford's extraction techniques and modern atomic accelerators allowed the team to date the ancient collagen with much greater precision than past tests.

Combining the new radiocarbon dates with previous ages they considered reliable, Waters and Stafford assembled a new Clovis time range: 13,125 to 12,925 calendar years ago.

Previously, archaeologists thought Clovis arrived in North America about 13,600 years ago and vanished about 12,900 years ago. If Clovis hunters weren't the first Americans, then where did pre-Clovis peoples come from, and when did they arrive? That's one of the most hotly debated topics in archaeology.

Some researchers suggest the earliest American explorers sailed boats from northeastern Asia, then navigated down the West Coast, beginning 20,000 or more years ago.

And despite the latest findings, a small but vocal group of archaeologists cling to Clovis First.

Gary Haynes, of the University of Nevada, said it's "nonsense" to claim that the new results disprove the theory. He said Waters and Stafford have been "very selective about what data they want to accept and what data they want to ignore."

The Clovis hunters

• Roamed North America 13,125 to 12,925 years ago.

• Named after the New Mexico town where stone projectile points were found with mammoth remains in 1933.

• Stalked mammoths and other animals, including bison, horses, camels, tapirs, antelope, bears and jackrabbits.

• Left behind distinctive tapered stone spear points with scooped-out vertical channels, called flutes, on both faces.Source: Archaeology Of The Southwest, By Linda Cordell

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