Yesterday, Harvard University researchers published research in the journal Nature which shows close DNA connection between indigenous peoples of the Amazon Basin of South America and aboriginal people of Australasia (including Australia, New Zealand, Papua, New Guinea and surrounding islands).
The researchers looked at the data several times because it differed from their previous models of the spread of the human population. Skoglund et al found the genomic evidence to be even stronger as they looked harder to show there was not a tie between the two population groups.
"Skoglund and colleagues from HMS, the Broad and several universities in Brazil analyzed publicly available genetic information from 21 Native American populations from Central and South America. They also collected and analyzed DNA from nine additional populations in Brazil to make sure the link they saw hadn't been an artifact of how the first set of genomes had been collected. The team then compared those genomes to the genomes of people from about 200 non-American populations."
"The link persisted. The Tupí-speaking Suruí and Karitiana and the Ge-speaking Xavante of the Amazon had a genetic ancestor more closely related to indigenous Australasians than to any other present-day population. This ancestor doesn't appear to have left measurable traces in other Native American groups in South, Central or North America."
"The genetic markers from this ancestor don't match any population known to have contributed ancestry to Native Americans, and the geographic pattern can't be explained by post-Columbian European, African or Polynesian mixture with Native Americans, the authors said. They believe the ancestry is much older--perhaps as old as the First Americans."
"The team named the mysterious ancestor Population Y, after the Tupí word for ancestor, 'Ypykuéra.' "
The researchers propose that Population Y and First Americans came down from the ice sheets to become the two founding populations of the Americas.
"About 2 percent of the ancestry of Amazonians today comes from this Australasian lineage that's not present in the same way elsewhere in the Americas," said David Reich, one of the contributing authors.
An Australasian heritage for Amazonian people is one of the last connections that would come to my mind, given the geographical isolation of Australasia for such a long time period. What's your thinking about this migration pattern?
Two additional links on this topic from The New York Times and The Smithsonian.
Scratching my head over this one,
This world map projection is helpful:
You can just about see Gilligan in the middle of the Pacific. . .
And with the wind patterns: