Ancient DNA analyses of archaeological remains of R. exulans
indicated that there was indeed continuity between ancient and
modern populations on most islands (Matisoo-Smith, 2002), and
therefore both ancient and modern mtDNA data could be combined
and were useful in addressing the question of population origins.
The approach was then applied beyond Polynesia to address the
questions regarding the links between Polynesia, Lapita, and
R. exulans populations in Near Oceania and Island Southeast Asia
(Matisoo-Smith and Robins, 2004). Interestingly, archaeological
evidence suggests that R. exulans was not present in Taiwan, the
postulated homeland of the Austronesian languages and, by association,
also possibly of the Lapita culture. This evidence suggested
that at least this one component of the Lapita cultural complex had
to have been picked up and incorporated elsewhere prior to its
introduction to the Pacific. The mtDNA data from the rats also
indicated that there were several distinct populations and likely
interaction spheres across Island Southeast Asia and the Pacific, two
of which were found on the Pacific islands