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Tax-team leader: Craig Moritz, University of California Berkeley
Full team

Background:

Relative to other taxa, the vertebrates of Moorea are depauperate in terms of species numbers, yet they are prominent, ecologically significant and represent an excellent group with which to study the impacts of invasive species. In the pilot project, attention was focused on the reptiles, which have been widely assumed to represent a wholly invasive group, associated with both early Polynesian and subsequent European colonization. A 1 week sampling effort provided population-level sampling of the most abundant species, including one (Hemidatylus frenatus) that has colonized and spread around the island's perimeter in the past decade and another (Phelsuma laticauda) even more recent entry. In collaboration with a local biologist, we also obtained sequences of foraging individuals of 2 marine turtle species from Moorea and other regions of French Polynesia. Sequencing of the Barcoding locus showed that genetic diversity does not predict invasion history, in that a presumed "native species" (Gehyra oceanica) had low diversity, whereas the recently invasive H.frenatus has very high diversity, similar to that across its native range in SE Asia. We also found that foraging green turtles from Moorea (and other Society Islands) were genetically distinct from those in the Marquesas, and that the latter are possibly derived from Micronesian breeding populations. Finally, we developed a high sensitivity approach to genetically analyzing invasion dynamics for another species, Lepidodactylus lugubris, which has both diploid and triploid populations on Moorea.

Significance:

This project will involve scientists from both UCB and NHM Paris and a turtle biologist from French Polynesia, thereby extending the intellectual and institutional reach of the MBP. The bar-coding data will contribute to global databases, and for marine turtles, to Pacific-wide conservation programs. More fundamentally, the results for reptiles and mammals will shed light on current debates about the connection between genetic diversity and invasiveness and on the role of human migrations in shaping biodiversity in the tropical Pacific. The genotypic data for lizards will prompt further development of bioinformatics tools for handling molecular data associated with field surveys and museum specimens.