Explanation:
Indigenous peoples in South America, Australia, and New Guinea share a common ancestry, according to a study published today in the journal Nature.
Researchers looked at the DNA of 30 Native American populations in Central and South America. They found that some groups -- mainly two tribes in the Amazons of Brazil -- share ancestry with indigenous groups in Australia, New Guinea, and the Andaman Islands off the coast of India.
But the shared genetic material was not found in other present-day Native American populations, according to the study. And it wasn't found in East Asian groups that have been connected to some present-day Native Americans.
The discrepancy led some researchers to conclude that the Americas were populated by another set of ancestors not previously known to scientists. Many of them believe Native Americans descend from a similar, or even single, group of people.
