The first Americans arrived in the current United States more than a thousand years earlier than expected, according to a new study.
Experts suggest that people lived in the area as many as 16,500 years ago, a whole millennium earlier.
They came to the conclusion after stone tools and other artifacts were excavated at an archaeological excavation site at the Cooper & # 39; s Ferry site in Idaho.
The artifacts are considered to be one of the earliest evidence of people in North America.
The findings add weight to the theory that human migration to mainland America followed a Pacific coastal route.
Previous research suggests that people first arrived from East Asia around 20,000 years ago in East Asia, across Beringstraat, a country immersed in the last ice age.
Early human migration came through Alaska, and the first people who arrived actually came from three different genetic groups.
One group, the Ancient Beringians, remained in the region for thousands of years after arrival, before it was completely replaced or crossed with Indians.
Another group, the descendants of the Indians, then split into two groups – one conquered North America while the second ventured into South America.
The first Americans arrived in the current United States more than a thousand years earlier than expected, according to a new study. This map shows a possible Pacific Coast coastal migration route for early Americans.
Cooper & # 39; s Ferry, located at the confluence of Rock Creek and the lower salmon river, is known by the Nez Perce tribe as an old village site called Nipéhe.
The site contains two excavation areas, A and B, and the published findings are about artifacts found in area A.
In the lower part of that area, researchers discovered several hundred artifacts, including stone tools, charcoal, fire-cracked rocks and bone fragments, probably from medium to large animals.
They also found evidence of a firebox, a food preparation area and other pits that were created as part of household activities on the site.
The lead author of the research, Professor Loren Davis of Oregon State University, said: & The Cooper's Ferry site is located along the Salmon River, a tributary of the greater Columbia River basin.
& # 39; Early peoples moving south along the Pacific coast would have come across the Columbia River as the first place among the glaciers where they could easily walk and paddle to North America.
& # 39; The Columbia River corridor was essentially the first exit of a Pacific Ocean migration route.
& # 39; The timing and position of the Cooper & # 39; s Ferry site is consistent with and easiest to explain as the result of an early migration from the Pacific coast. & # 39;
Experts suggest that people lived in the area 16,000 years ago, a whole millennium before. They came to the conclusion after stone tools and other artifacts were excavated at an archaeological excavation site at the Cooper & # 39; s Ferry site in Idaho (photo)
Professor Davis first began studying Cooper as Ferry in the 1990s as an archaeologist.
In the past two summers, a team of students and researchers reached the lower layers of the site, which contained some of the oldest uncovered artifacts.
Professor Davis worked with a team of researchers from Oxford University who were able to successfully date a number of animal bone fragments.
The results showed that many of the artifacts from the lowest layers are associated with dates in the range of 15,000 to 16,500 years old.
Professor Davis said: & # 39; Prior to getting this age with radio-carbons, the oldest things we had found predominantly date back to the 13,000-year range and the earliest evidence of people in America was dated just before 14,000-year-old in a handful of other sites.
& # 39; When I first saw that the lower archaeological layer contained radio-charcoal times older than 14,000 years, I was astonished but skeptical and had to repeat those figures over and over to make sure they were right.
& # 39; So we had more radiocarbon data and the bottom layer was between 14,000 and 16,000 years old. & # 39;
WHEN THE NORTH AND SOUTHERN NATIVES DIVIDE?
While the Ancient Beringians separated from all other Indians about 20,000 years ago, the northern and southern groups later diverged.
Based on earlier research, this suggests that they must have already been on the American continent south of the glacier ice when they diverged.
The gap was probably created after their ancestors had passed the ice caps Laurentide and Cordilleran.
These are two huge glaciers that covered current Canada and parts of the northern United States, but started to thaw around this time.
The ice sheet isolated southern travelers from the Ancient Beringians in Alaska, who were eventually replaced or taken in by other Native American populations.
Although modern populations in Alaska and Northern Canada belong to the North American branch, the new analysis shows that these stem from a later & # 39; back & # 39; migration to the north long after the initial migration events.
The data from the oldest artifacts challenge the long-cherished & # 39; Clovis First & # 39; theory of early migration to America, suggesting that people cross over from Siberia to North America and through an opening in the ice sheet near today's Dakotas traveled.
It is believed that the ice-free corridor was opened as early as 14,800 years ago, well after the date of the oldest artifacts found on Cooper's Ferry.
Professor Davis added: & # 39; Now we have good evidence that people were in Idaho before that corridor was opened.
& # 39; This evidence leads us to the conclusion that early peoples moved south of continental ice sheets along the Pacific coast. & # 39;
Researchers also found tooth fragments on Copper & # 39; s Ferry from an extinct form of horses known to have lived in North America at the end of the last ice age.
Professor Davis said that the dental fragments, together with the dating with radiocarbon, show that Cooper & # 39; s Ferry is North America's oldest radiocarbon dating site with artifacts associated with the bones of extinct animals.
He said that the oldest artifacts found on Cooper & # 39; s Ferry are also very similar in shape to older artifacts found in Northeast Asia, especially Japan.
The data from the oldest artifacts challenge the long-cherished & # 39; Clovis First & # 39; theory of early migration to America, a distinctive DNA type associated with the Clovis culture found in Chile, Brazil and Belize dates it to 11,000 and 9,000 years ago
Professor Davis is now working with Japanese researchers to compare further artifacts from Japan, Russia and Cooper & # 39; s Ferry.
He is also waiting for information on carbon dating of further finds from a second excavation at the Cooper & # 39; s Ferry site.
Professor Davis added: & # 39; We have 10 years of excavated artifacts and samples to analyze.
& # 39; We expect that we will make other exciting discoveries as we continue to study the artifacts and samples from our excavations. & # 39;
The full findings were published in the journal Science.
Cooper & # 39; s Ferry (photo), located at the confluence of Rock Creek and the lower salmon river, is known by the Nez Perce tribe as an old village site called Nipéhe. The site contains two excavation areas, A and B, and the published findings are about artifacts found in area A
WHO WERE THE OLD BERINGIANS?
A single ancestral Indian population first emerged as a separate group about 36,000 years ago in Northeast Asia.
Constant contact with Asian populations lasted until about 25,000 years ago, when the gene flow between the two groups stopped.
This cessation was probably caused by brutal climate changes that isolated the native American ancestors.
At this point the group probably started to cross over to Alaska via an old land bridge over the Beringstraat that was submerged at the end of the last ice age.
Then, about 20,000 years ago, that group split into two genera – the Ancient Beringians and the ancestors of all other Indians.
At least the Beringians continued to breed with their Indian cousins until the Upward Sun River girl was born in Alaska about 8,500 years later.
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