The team from the Natural Environment Research Council and led by Dr Silvia Gonzalez, analysed the DNA of skulls with markedly different morphologies to Native American Indians, commonly regarded as the first settlers of the Americas. The skulls are long and narrow, not in keeping with the Native Indians' broader, rounder features.
"They appear more similar to southern Asians, Australians and populations of the South Pacific Rim than they do to Northern Asians," said Dr Gonzalez of Liverpool John Moores University.
"DNA analysis of the Mexican remains suggest these people were at least partly contemporaneous to the first native American Indian settlers on the continent," she added.
"We think there were several migration waves into the Americas at different times by different human groups. The timing, route and point of origin of the first colonisation of the Americas remains a most contentious topic in human evolution."
This debate has been running for more than a century. Consensus is split between two camps: the first camp believe settlers came across the Bering Straits, from Russia to Alaska, at the end of the last ice age 12-15,000 years ago. Evidence for this theory comes from Clovis Points - huge tools used to hunt mammoths - found all over the American continent. DNA analysis of skeletal remains close to these Clovis Points suggest just four tribes are responsible for populating the continent. The second camp say colonisation happened much earlier than this, 20-30,000 years ago, but their techniques, using genetics, linguistics and dental morphology, have been steeped in controversy.
Dr Gonzalez's team have evidence of a previously unknown group, the Pericues, who went extinct in the 18th Century. She suggests this tribe may not have taken the traditional route to the continent.
The work is one of 11 projects investigating whether environmental factors played a part in human evolution and dispersal. Funded by the Natural Environment Research Council, the programme is tackling major anthropological questions such as: how did we become the only true global species? Why did our ancestors swap the tropical beaches of Africa for the icy tundra? How do we explain our trademark big brains? What role did climate play in making us adapt quickly to different environments?
The programme, Environmental Factors in the Chronology of Human Evolution and Dispersal, is truly global in its outlook with scientists working in South America, Europe, Africa, the Middle East and southern Asia.
The Natural Environment Research Council (NERC) is one of the UK's seven Research Councils. It uses a budget of about £300 million a year to fund and carry out impartial scientific research in the sciences of the environment. It is addressing some of the key questions facing mankind such as global warming, renewable energy and sustainable economic development.
For more information on NERC's Environmental Factors in the Chronology of Human Evolution and Dispersal programme see http://www.
The UK's progressive science and technology environment makes it the partner of choice for world-leading researchers, developers and academics eager to turn knowledge into innovation. Learn more about how the UK is developing science and technology for a new world at http://www.