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The first Americans entered the unknown from Asia



Almost 11,000 years ago, a man died in what is now Nevada. He was wrapped in a rabbit skin and reed mats and buried in a place called Spirit Cave.

Scientists have now discovered and analyzed his DNA, along with that of 70 other ancient humans whose remains have been discovered throughout America. The results give a story lost to prehistory, amazing details: how and when people spread in the Western Hemisphere.

The earliest known arrivals from Asia have already split into identifiable groups, according to the study. Some of these populations flourished and became ancestors of indigenous peoples throughout the hemisphere.

But other groups died out completely leaving no trace beyond what one can recognize in the old DNA. In fact, the new genetic research points to many dramatic chapters in the peoples of America that archeology has not yet discovered.

"Well, that's the bottom for archaeologists," said Ben Potter of the University of Alaska involved in the new papers. "Holy Cow, that's great."

Earlier studies had shown that at the end of the last Ice Age, humans had moved to America and traveled from Siberia to Alaska across a land bridge now under the Bering Sea. They spread south, eventually reaching the tip of South America.

Until recently, geneticists could give little insight into these formidable migrations. Five years ago, in the Western Hemisphere, only one ancient human genome had been discovered: that of a 4,000-year-old male discovered in Greenland.

The latest analysis, published in three separate studies, marks a turnaround. In recent years, researchers have obtained the genomes of 229 ancient humans from teeth and bones discovered throughout America.

"It's basically an explosion," Dr. Willerslev.

The man from the Spirit Cave in Nevada belonged to this so-called southern branch of the migrants. He was also closely related to a 12,700-year-old boy who lived on the other side of the Rocky Mountains in Montana. Willerslev, was found.

In her new study, Dr. Reich and his colleagues no trace of population Y Willerslev's team, however, managed to identify the DNA in some of the 10,400-year-old skeletons in Brazil.

"The million question is natural, how did that happen?" Willerslev said.

Perhaps another group of Asians arrived in front of the ancestors of the man from Spirit Cave and other early Native Americans in America. Maybe they mingled with the people of the Amazon before they disappeared completely.

Or maybe some of the early members of the southern branch had random genes that survived for generations.

Improving the relationship between scientists and indigenous peoples. For decades, many tribes have rejected applications from researchers for DNA.

The man from Spirit Cave was excavated in 1940 by archaeologists and kept in a museum. The local tribe, the Fallon Paiute-Shoshone, did not learn about the body until 1996. They fought for years for the repatriation.

"It is completely disrespectful," said Rochanne L. Downs, member of the tribal culture committee. "If someone had gone to Arlington Cemetery and dug a soldier's grave and received his medals, there would be outrage."

Initially, the strain opposed the search for DNA in the skeleton because scientists would have to destroy much of it. Dr. Willerslev met with the tribe and explained that he only needed one tooth and a small piece of ear bone.

The tribe agreed to give it a chance to find DNA in the Spirit Cave remains.

Dr. Willerslev's findings prompted the Bureau of Land Management to hand over the skeleton to the tribe. They buried the man of Spirit Cave in an unknown place last year.

Downs would not rule out similar studies in the future, but said every request needed careful consideration.

"It will all happen on a case by case basis," she said. "The main thing is our respect for the remains."


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