Aboriginal type early Americans

[Ayinde]

Skulls found in Mexico suggest the early Americans would have said 'G'day mate'

By Steve Connor, Science Editor
04 September 2003

The accepted theory of how prehistoric humans first migrated to America has been challenged by a study of an ancient set of bones unearthed in Mexico.

An analysis of 33 skulls found on the Mexican peninsula of Baja California suggests that the first Americans were not north Asians who crossed to the American continent about 12,000 years ago.

The skulls more closely resemble the present-day natives of Australia and the South Pacific, suggesting that there might have been an earlier movement to America across the Bering Strait separating modern Russia from Alaska.

The research, published in today's issue of the journal Nature, is the latest twist in the controversy over who were the first Americans and how did they arrive in the New World?

Native Americans today bear a close physical resemblance to north-east Asians and anthropologists have long believed that this is because they are both descended from the same ancestors, some of whom migrated to America across the Ice Age bridge that spanned the Bering Strait.

However, a team of scientists led by Rolando Gonzales-José of the University of Barcelona in Spain believes that a different scenario could have occurred prior to the accepted migration of northern Asians.

Dr Gonzales-José and his colleagues analysed the shape and dimensions of 33 skulls of a tribe of people who lived near the western Mexican coast of Baja California between 2,500 and 300 years ago.

These relatively long and narrow skulls share a closer affinity to the skulls of the present-day inhabitants of south Asia and the southern Pacific Rim.

This suggests that these particular people could not have shared the same ancestor as present-day native Americans whose skulls more closely resemble broad and short shape of northern Asians.

Tom Dillehay, an anthropologist from the University of Kentucky in Lexington, said the accepted idea of how America became populated with humans was probably far too simple. "More recent archaeological discoveries suggest that there were several different founding populations, arriving from different places," Dr Dillehay said.

"To complicate matters further, it is no longer certain that the first colonisers arrived about 12,000 years ago - some archaeological sites in South America date from 12,500 years ago, which suggests that the first humans arrived at least 15,000 years ago," he said.

Dr Dillehay said the ancient people who lived on the long peninsula of Baja California probably became isolated from the rest of the north American population. This meant they retained the much older ancestral trait of a long and narrow skull.

http://news.independent.co.uk/world/science_medical/story.jsp?story=440002

[Ayinde]

11:24 04 September 03
 
NewScientist.com news service
 
Skull measurements on the remains of an isolated group of people who lived at the southern tip of Mexico's Baja California has stirred up the debate on the identity of the first Americans once again.

The earliest inhabitants of North America differed subtly but significantly from modern native Americans. The difference is clearly seen in the skull shapes of the first people to colonise the continent, who had longer, narrower skulls than modern people.

One theory says it is because two distinct groups of people migrated to North America at different times. But another theory says that just one population reached the continent and then evolved different physical attributes, except for a few isolated groups.

Anthropologists once assumed the earliest Americans resembled modern native Americans. That changed with the discovery of a 10,500-year-old skeleton called Luzia in Brazil, and the 9000-year-old skeleton of Kennewick man in Washington state.

Both had the long, narrow skulls that more resemble those of modern Australians and Africans than modern native Americans, or even the people living in northern Asia, who are thought to be native Americans' closest relatives.

Some researchers argued that they were simply unusual individuals, but scientists have now identified the same features in recent remains from the Baja California.

Desert island

The Pericú hunter-gatherers survived until just a few hundred years ago at the end of the peninsula, says Rolando González-José, of the University of Barcelona, Spain, (Nature, vol 425, p 62).

He thinks the formation of the Sonora desert isolated the Pericú for thousands of years, but they vanished when Europeans disrupted their culture. González-José measured 33 Pericú skulls and found their features were similar to those of the ancient Brazilian skulls.

This backs the idea that a first wave of long, narrow skulled people from south-east Asia colonised the Americas about 14,000 years ago. These were followed by a second wave of people from north-east Asia about 11,000 years ago, who had short skulls.

This theory has been championed by Walter Neves, at the University of Sao Paulo, Brazil. He says the second wave may have been larger, and eventually came to dominate the Americas. "The discovery is exactly what I have been predicting since the late 1980s," Neves told New Scientist.

However Joseph Powell, an anthropologist at the University of New Mexico in Albuquerque, is not convinced. He thinks the earliest Americans did come from south-east Asia, but believes they evolved into modern native Americans.

"Even with two waves, each would have changed over the past 10,000 to 12,000 years through adaptation and microevolution," he says. Neves argues that the change in skull shape after 8000 years ago is too sudden for evolution.

Journal reference: Nature (vol 425, p 62)

http://www.newscientist.com/news/news.jsp?id=ns99994128