PARENT SESSION

Systematics/Zoogeography 3 -- Session Chair: Phil Sudman-- Nelson Hall East, Goodwin Forum

REDUCED MTDNA DIVERSITY IN ENDEMIC PHILIPPINE FRUIT BATS ON SMALL, ISOLATED ISLANDS. Trina E. Roberts^1,2. ¹ Committee on Evolutionary Biology, University of Chicago, Chicago, IL; ² Field Museum of Natural History, Chicago, IL.

ABSTRACT- The oceanic portion of the Philippine archipelago comprises thousands of islands from less than 100 to over 100,000 square kilometers in area. Some groups of islands were repeatedly connected by land bridges during Pleistocene episodes of low sea level, while others have been continuously isolated. No land bridge connection has ever existed between the oceanic Philippines and other parts of Southeast Asia or the Sunda Shelf. Using fragments of the mitochondrial genes ND2 and cytb, I compared levels of genetic diversity in fruit bats on continuously isolated islands and on land bridge islands within the Philippines. Isolated islands ranged from 249 km² to 9,735 km² and land bridge islands ranged from 498 km² to 107,170 km². In general, genetic diversity is quite high in all the species I studied. In the Philippine endemics Haplonycteris fischeri and Ptenochirus jagori, diversity levels are lower on small, continuously isolated islands than on land bridge islands. This effect is not apparent in the non-endemic species Cynopterus brachyotis and Macroglossus minimus, and it is independent of the overall level of phylogeographic structure.

KEY WORDS: Pteropodidae, genetic diversity, Chiroptera, Philippines