for National Geographic News
A study of skulls excavated from the tip of Baja California in Mexico suggests that the first Americans may not have been the ancestors of today's Amerindians, but another people who came from Southeast Asia and the southern Pacific area.
The question of who colonized the Americas, and when, has long been hotly debated. Traditionally, Native Americans are believed to have descended from northeast Asia, arriving over a land bridge between Siberia and Alaska some 12,000 years ago and then migrating across North and South America.
But recent research, including the Baja California study, indicates that the initial settlement of the continent was instead driven by Southeast Asians who occupied Australia 60,000 years ago and then expanded into the Americas about 13,500 years ago, prior to Mongoloid people arriving from northeast Asia.
The skulls from Baja California, which may date back only a few hundred years, have slender-looking faces that are different from the broad-cheeked craniums of modern Amerindians, the descendants of the Mongoloid people.
"Our results change the traditional idea that all modern Amerindians present morphological affinities with East Asians as a result of a single migration," said Rolando González-José of the University of Barcelona, Spain, who led the study. "The settlement of the New World is better explained by considering a continuous influx of people from Asia."
The new study is reported in this week's issue of the science journal Nature, and could further fuel the controversy surrounding the origins of the first Americans, which is a controversial issue for American Indians in particular.
Conventional wisdom says that Native Americans descended from prehistoric hunters who walked from northeast Asia across a land bridge, formed at the end of the Ice Age, to Alaska some 12,000 years ago. American Indians resemble the people of Mongolia, China and Siberia.
In the 1930s, archeologists found stone spear points among the bones of mammoths near Clovis, New Mexico. Radio carbon dating in the 1950s showed that the oldest site was 11,400 years old. The sites were assumed, for years, to be the first evidence of human occupation in the Americas.
But more recent discoveries challenge the Clovis story. In 1996, archeologists in southern Chile found weapons and tools dating back 12,500 years. In Brazil, they found some of the oldest human remains in the Americas, among them a skeletonnamed Luziathat is more than 11,000 years old.
Luzia did not look like American Indians. Instead, her facial features matched most closely with the native Aborigines in Australia. These people date back to about 60,000 years and were themselves descended from the first humans who probably originated in Africa.
The researchers believe Luzia was part of a people, referred to as "Paleoamericans," who migrated into the Americaspossibly even by boatlong before the Mongoloid people. These Paleoamericans may later have been wiped out by or interbred with Mongoloids invading from the north.
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