COLLEGE STATION, TEXAS — Scientists along Buttermilk Creek north of Austin have found flint knife blades, chisels and other human artifacts lying in a soil layer nearly 16,000 years old — a discovery they say will re-write a major chapter of ancient human history.
For one thing, it is now the oldest and arguably most credible site of human occupation in North or South America — but there's more.
The discovery, by Texas A&M archaeologist Michael Waters and others, pushes back by 2,500 years the time when traditional science thought humans entered the New World from Siberia and established the native populations of North and South America.
"This discovery ought to be like a baseball bat to the side of the head," to past theories, Waters said. Other ancient sites in the Americas usually produce only handfuls of artifacts, in soils with ages that scientists argue about. This site contained tools in layer after layer of soils stacked like layer cake, the youngest from modern times, the oldest layer containing 15,000 artifacts dated to 15,500 years ago.
While Waters is at Texas A&M, much of the work involving ancient Americans is taking place in Kansas.
Two strong theories
The discovery strengthens the case for two theories that traditional archaeologists laughed at not long ago — that the first Americans came earlier than 13,000 years ago, and that they didn't walk over a land bridge into North America from Siberia, but came by skin boats at least 16,000 years ago (or long before) skirting along coastlines of the Aleutian Islands off Alaska, and then down the coast of North America.
Waters believes they came by boat, hunting seals beside Ice Age glaciers a few miles at a time, surviving Ice Age weather, bringing families and pet dogs. He thinks the first colonies in America sprouted tens of thousands of years ago along the Columbia River basin between Washington and Oregon, a region he said archaeologists should re-explore with renewed vigor.
This story is important to all of us, he said: Most Americans think Columbus should be taught in schools, but the first discovery of America was more heroic than his voyage, and far older.
It's a story that Waters and other scientists have spent decades trying to get right, including with dig sites in Kansas. The first Americans, or Paleo Indians, were the first to explore the Rockies and Andes, the Mississippi, the Amazon. They were first to see mammoths and bison roaming Ice Age Kansas. They dodged giant dire wolves, giant short-faced bears, saber-toothed cats, and American lions.
They took significant risks — hunting elephants with spears, at arm's length, taste-testing possibly lethal plants to find which were good as food or medicine; they hunted with grannies and children not only coming along but driving herds into hunter ambushes.
"One thought that deeply touches my sense of wonder is that they didn't really have to migrate once they got here," Waters said. "Everywhere they would go, they'd find a land empty of people, with huge amounts of resources. And yet they migrated all the way to the tip of South America, and the only explanation is the relentless human spirit of adventure. And they were bringing not only their wives and elderly but their pregnant wives and their babies."
What he found
The tools found in Texas are flint blades small and thin, designed by people who carried everything they owned. It is likely that flint tools made up only 5 percent or so of the belongings of these people.
One artifact gave Waters a thrill: a golf-ball-sized nodule of hematite, worn flat on several sides the way schoolroom chalk wears flat. Hematite, when mixed with animal and plant oils, produces red ochre — paint to adorn spear shafts, clothing — or skin. "These people from 15,500 years ago were decorating themselves."
Rolfe Mandel, a geoarchaeologist with the Kansas Geological Survey who has discovered important sites in Kansas, said the Texas discovery is "a very big deal," in part because it strengthens the possibility that humans entered the New World as early as 24,000 years ago, near the peak rather than at the end of the last Ice Age.
Waters said he would not go that far ("I can confirm only that they were here at least by 15,500 years ago," he said.). But Mandel and some geneticists say the evidence is growing.
Twenty-four thousand years ago would have been scoffed at by scientists only a few years ago. They believed people could not have come until 13,000 years ago.
The Texas discovery upends that, Mandel said. People didn't just enter Alaska and sprint with babies to Texas. They migrated, perhaps for centuries.
Mandel analyzed Waters' discovery paper for Science magazine, which published it Thursday. He said Waters found overwhelming evidence in a field of study where that almost never happens. Ancient Americans were so few, and created so few belongings that survived decay, that most camp or hunting sites contain only a few flint flakes. But Waters found thousands of artifacts in excavation blocks only about 50 meters square.
It's a world-class discovery; in recent days Waters has given interviews to science writers from the New York Times, Washington Post, and German Public Radio ("the Germans LOVE Paleo Indians," he said.).
Mandel said Waters has done much to solve a human origin mystery that other explorers got awesomely wrong for 519 years, starting when Columbus first stepped onto a Bahamas beach and called the natives "Indians."
Until recently, traditional science held that the first Americans were the "Clovis culture" hunter-gatherers who lived in North Americas 13,000 years ago. Scientists named the culture after Clovis, N.M., where the first such spear points were found in the 1920s.
Scientists thought Clovis hunters were the first Americans because geologists knew that mile-high Ice Age glaciers would have prevented anyone from migrating from Siberia through Alaska. The ice melted to let people through about 13,000 years ago, a time that dovetailed with the age of Clovis tools.
Waters said Clovis-first is a dead idea now, not only because of his discovery but of others. Archaeologists in the 1970s discovered 14,500-year-old wooden housing foundations, tent pegs and campfire ash in southern Chile at Monte Verde. That site was older than Clovis culture by 1,500 years, and located 10,000 miles south of the Siberian-Alaskan passageway, meaning humans not only had to enter Alaska but migrate halfway around the world to get there.
Other discoveries turned up in North America; artifacts appeared older than Clovis. (Search on the Internet for "Meadowcroft Shelter, Pennsylvania" and "Paisley Caves, Oregon.").
And DNA scientists, who believe they can determine a racial population's genetic age and relationships between ethnic groups with accuracy these days, are saying that Native Americans' ancestors came from Siberia, probably before 16,000 years ago.
Waters, director of the Center for the Study of the First Americans at Texas A&M, found Clovis artifacts along Buttermilk Creek a decade ago.
In 2006 his team dug beneath the Clovis layer.
"There was this a-ha moment. We found dozens and dozens of artifacts below the Clovis horizon, and when we dated the soils repeatedly, it kept showing that it was much, much older than Clovis. I thought... wow!"
Using luminescence dating, (measuring the amount of light energy trapped in sediment grains) and repeating the experiment with different sections of soils, he found an age of 15,500 years.
His team found 56 tools — knife blades, choppers, scrapers and notched whittling tools. Buttermilk was a camp, where hunters wanted only to whack a rough flint core to flake off razor-sharp butcher's blades.
Waters' team also found thousands of flakes of flint left over from manufacture.
The reason those chips will rewrite history is that Waters' critics all know that artifacts from one layer of soil can fall to an older layer through cracks in sun-baked soil, or from holes dug by gophers. But finding thousands of chips in one layer is hard to dispute. "When I saw that, I said, 'holy smokes,' " Waters said.
Some scientists will still dispute the site's age and his conclusions. In the office next door to Waters' in the anthropology building at Texas A&M on Monday, a Russian-speaking anthropologist, Kelly Graf, who has dug and explored in Siberia and Alaska, said Waters' conclusions about a much older colonization from Siberia were not supported by archaeological evidence: There are no sites of human occupation in Alaska older than 14,000 years and no physical evidence of people using boats near Alaska more than 20,000 years ago. That doesn't mean it didn't happen; it means the case is circumstantial.
Many strong cases are circumstantial, Waters said.
The age of giants
At 15,500 years ago, agriculture and the revolution it caused in human behavior would not come along in the Middle East for 5,000 years. There was no bow and arrow, which eventually made hunting easier and safer; no tamed animals except the dog; no cities, where people extend life and comfort with granaries and cooperation.
Nobody settled down for long. People lived to walk.
The Buttermilk Creek people probably ate well, though. Though Ice Age glaciers covered much of Europe (and North America all the way to what is now Des Moines), their landscape was filled with animals that would feed many, and intrigue us: mammoths and mastodons, peccaries — and camels and horses, which originated in North America but had died out before the Europeans arrived.
There were giant beaver 4 feet tall, giant armadillos, giant sloths and long-horned bison 20 percent bigger than bison today.
The people probably dug mussel shells out of creeks, probably settled often for small meals. "Hunting big game is dangerous, not as economical as you might think," said University of Kansas paleontologist Larry Martin. "You kill a big animal, you start worrying about big predators coming at it."
They were our equals in intelligence; their languages as complex as ours. "They no doubt told campfire stories, about mammoths, creation spirits and stars in the sky," Waters said. They likely had a shaman, someone who tried to help the hunters or the sick by connecting to the spirit world.
Winters were warmer, summers cooler. Texas was green parkland interspersed with conifers. Buttermilk Creek's spring-fed water runs all year; its banks hold huge layers of exceptional Edwards chert. Waters jokingly said the first words spoken when humans reached the creek were: "Look at all this tool-stone! Let's get the whole gang here!"
Along the creek, they rested and sharpened their tools.
Waters said they probably lived as richly and as happily as anybody who came after.