Study offers new clues about first Americans

July 30, 2001 Posted: 8:12 PM EDT (0012 GMT)

WASHINGTON (AP) -- The first people to cross a land bridge from Asia and settle in the Americas may have been descendants of an ancient group who once lived in Japan, according to a new study.

Researchers examining and measuring the bone structure of nearly 10,000 ancient human skulls collected from around the world say the first Americans were most closely related to the Jomon, a prehistoric people who lived in Japan thousands of years ago, and to a later group, the Ainu.

C. Loring Brace of the Museum of Anthropology at the University of Michigan said the skull measurements and other evidence suggest the members of the J omon-Ainu group crossed what is now the Bering Straits and migrated throughout the Americas, from Alaska to the tip of South America.

"These were not the people who now live in Japan," said Brace, lead author of a study appearing Tuesday in the Proceedings of the National Academy of Sciences. "Those people migrated to Japan later from Asia, but you can still find traces of the Jomon among the Japanese."

Brace said the Jomon had some characteristics of Europeans, along with Asian influences.

First migrants arrived thousands of years ago

Those first migrants reached the Americas about 15,000 years ago, he said, and within about 1,000 years there were people living near the tip of South America.

At the time of the first migration, ice covered much of the northern world, causing the worldwide sea level to drop by hundreds of feet. The Bering Strait, which is not much deeper than 60 feet in most places, was not there. Instead, there was a dry land bridge from Alaska to Siberia.

Brace said characteristics of the first migrants are now clearly seen in many of the American Indian tribes, including the Blackfoot, Sioux and Cherokee.

A second migration came some 3,000 to 4,000 years ago, Brace said, but these people were a mix of Chinese, Southeast Asian and Mongolian. They probably came by boat, he said, paddling across the Bering Strait, which had filled with water after the massive northern ice sheet melted.

Brace said people from this later migration became the Eskimo and Aleut, living in the far north. At least some migrated south and are represented today by the Navajo, he said.

Computer analysis aids researchers

The conclusions are based on a detailed analysis and measurement of 21 bone characteristics in ancient skulls collected by museums and researchers all over the world, Brace said. A computer analysis of the thousands of measurements reveals a pattern of similarity that enables the researchers to connect peoples from different parts of the world.

Co-authors of the study include scientists from China and Mongolia.

There is strong evidence to suggest that the Jomon peoples in Japan were skilled boat builders, Brace said. He said they probably used boats to move down the west coast of the Americas, settling wherever game and food plants were plentiful.

"These were hunters and gatherers," he said. "This was thousands of years before agriculture. But they had boat technology."

Evidence of this is the birchbark canoe, Brace said. Ancient examples of that sturdy craft have been found in Japan and closely resembled the canoe later commonly used by natives in the Americas, he said.