While we’re on the topic of the Austronesian migration, the same issue of Science also carried another article about the tracing of human migration through the pacific. This time, the tracing of human bacteria indicate two splits of pacific populations from Asian ones, the first occurring around 30,000 years ago, while the second through one of the Austronesian subgroups 5,000 years ago.
The Peopling of the Pacific from a Bacterial Perspective
Science, 23 January 2009
Two prehistoric migrations peopled the Pacific. One reached New Guinea and Australia, and a second, more recent, migration extended through Melanesia and from there to the Polynesian islands. These migrations were accompanied by two distinct populations of the specific human pathogen Helicobacter pylori, called hpSahul and hspMaori, respectively. hpSahul split from Asian populations of H. pylori 31,000 to 37,000 years ago, in concordance with archaeological history. The hpSahul populations in New Guinea and Australia have diverged sufficiently to indicate that they have remained isolated for the past 23,000 to 32,000 years. The second human expansion from Taiwan 5000 years ago dispersed one of several subgroups of the Austronesian language family along with one of several hspMaori clades into Melanesia and Polynesia, where both language and parasite have continued to diverge.