Professor Diarmaid Ó Foighil and EEB graduate student Cindy Bick have been awarded a grant from the National Geographic Society’s Committee for Research Exploration for their studies with a highly endangered tree snail family endemic to the Pacific oceanic islands.

The $24,000 grant will support Bick’s research on the role of prehistoric humans in introducing partulid tree snails to Papua New Guinea (PNG) and on reconstructing prehistoric East-West exchange networks in Near Oceania (PNG and the Solomon Islands). The research will greatly increase understanding of regional partulid diversity, thereby enabling the development of an informed conservation strategy for these snails.

Partulid trees snails on the island archipelagos of PNG have extraordinary multi-archipelago ranges and their association with coastal villages strongly implicates prehistoric human introduction as the regional dispersal mechanism. Extensive exchange networks have interconnected regional island groups since at least 3300 BP* with the first appearance of settlers on the Pacific Islands who were responsible for populating Remote Oceania. The earliest populated sites are predominantly located on small offshore islands and in coastal regions of larger PNG islands, a distribution pattern that matches that of PNG partulid snail populations.

The study aims to find the source island/archipelago for PNG partulids. Candidate islands spanning Near Oceania and the Near/Remote Oceania boundary will be sampled and their tree snails genotyped for nuclear and mitochondrial markers. Source island/archipelago populations are predicted to occur in native forest habitat, to be genetically inclusive of the founder PNG populations and to contain sister species of the founder lineage. Results will yield novel insights into regional east-west prehistoric exchange networks and will provide an independent test of regional interaction models addressing the human settlement of Remote Oceania.

*Before Present, using January 1, 1950 as the origin of the time scale because radiocarbon dating came into use in the 1950s.

Journal of Biogeography

Captions: Top photo from of Partula rosea. Bottom photo: Tahitian partulids. Partula hyalina on right (white shell) and Partula clara's shell is yellowish/brown (juvenile on far right ). Credit: Trevor Coote.