Germ to reveal exodus of ancient peoples

Whites in Australia tend to be infected with European bacteria. Maoris have a version that arose in East Asia, and the lack of diversity in their bacteria shows that only a small number were able to island-hop to New Zealand about a thousand years ago, the study concludes.

Native Americans have more genetically diverse bacteria derived from the same group as the New Zealanders, revealing the bug first made it to the New World more than 12,000 years ago when people crossed the Bering Strait from Siberia to Alaska.

The research is an important contribution to understanding the pathogen, says Australia’s leading expert Barry Marshall of the University of Western Australia. The research could explain why Aborigines did not get stomach ulcers before colonisation.