In response to these questions and constrained by the ethical
and political issues of collecting DNA or tissue samples from either
ancient or modern indigenous populations in the Pacific, a new
approach to studying human migration patterns was developed.
What became known as the commensal approach focused on genetic
analyses of the plants and animals that people transported in
their colonizing canoes (Matisoo-Smith, 1994). Many of these
introduced species cannot self disperse and therefore had to be
introduced by humans. The animals introduced by Lapita were said
to include the dog, pig, chicken and the Pacific rat (Rattus exulans).
These animal remains often appear in the archaeological sites
across the Pacific, and in relatively large numbers compared with
human remains. It was also believed that there was limited mtDNA
variation in human populations in the Pacific, particularly Polynesia,
yet there was a chance of significantly more variation in the
commensal animals, which might allow for the identification of the
specific origins of the colonizing canoes of locations like New
Zealand and Easter Island.