Scientists have discovered hundreds of skulls in Central and South America, some dating back to over 11,000 years ago, that have cranial features distinctive to Australian Aborigines.
The oldest female skeleton, dubbed Luzia, is between 11,000 and 11,400 years old. The dating is not exact because the material in the bones used for dating has long since degraded.
Evolutionary biologist Walter Neves of the University of Sao Paulo examined these skeletons and recovered others, and argued that there is now a mass evidence indicating that at least two different populations colonised the Americas.
He and colleagues in the United States, Germany and Chile argued that first population was closely related to the Australian Aborigines and arrived more than 11,000 years ago.
The second population to arrive was of humans of 'Mongoloid' appearance-a cranial morphology distinctive of people of East and North Asian origin-who entered the Americas from Siberia and founded most (if not all) modern Native American populations, he argued.
"The results suggest a clear biological affinity between the early South Americans and the South Pacific population. This association allowed for the conclusion that the Americas were occupied before the spreading of the classical Mongoloid morphology in Asia," Cosmos magazine quoted Neves as saying.
Until about a decade ago, the dominant theory in American archaeology circles was that the 'Clovis people'-whose culture is defined by the stone tools they used to kill megafauna such as mammoths-was the first population to arrive in the Americas.
But in the late 1990s, Neves and his colleagues re-examined a female skeleton that had been excavated in the 1970s in an extensive cave system in Central Brazil known as Lapa Vermelha.
The skeleton-along with a treasure trove of other finds-had been first unearthed by a Brazilian-French archaeological team that disbanded shortly after its leader, Annette Laming-Emperare, died suddenly.
A dispute between participants kept the find barely examined for more than a decade.
"We believe she is the oldest skeleton in the Americas," said Neves.
Luzia has a very projected face; her chin sits out further than her forehead, and she has a long, narrow brain case, measured from the eyes to the back of the skull; as well as a low nose and low orbits, the space where the eyes sit. (ANI)