Gut bacteria reveals human migrations A bacterial parasite known
to cause stomach ulcers is shedding new light on ancient
patterns of human migration across the Pacific region, according
to an international study. In the latest edition of Science,
researchers report that their study of the distribution of
Helicobacter pylori genotypes has given further weight to the
theory that Australia was first populated around 30,000 years
ago. H. pylori is particularly useful for studying the movement
of human populations because it is extremely widespread, and is
transmitted from mother to child. Co-author Professor Barry
Marshall, a microbiologist at the University of Western
Australia, says H. pylori is a lot like mitochondrial DNA, which
is also used to investigate human migration patterns. "You catch
[H. pylori] off your mother," says Marshall. "All of us carry
our mothers' mitochondrial DNA and that goes all the way back
through the generations." H. pylori has a further advantage in
that it contains thousands of ge