Biogeography of the Indonesian archipelago: mitochondrial DNA variation inthe fruit bat, Eonycteris spelaea

The fruit bat, Eonycteris spelaea, occurs from India through the Philippine s to the southeast limit of its distribution in the Lesser Sunda islands of Indonesia. Mitochondrial DNA (mtDNA) variation was examined in Indonesian E. spelaea island populations by amplification of the D-loop and digestion with restriction endonucleases. In addition: microgeogaphic Variation was a ssessed by investigation of three cave populations within one island. A tot al of 24 genotypes, comprising two broad clades, was detected. The pattern of mtDNA variation reflects the colonization history off. spelaea with esti mates of haplotype and sequence diversity highest in the older western popu lations and lowest at the eastern periphery of the species' distribution. T hese findings may also be associated with an environmental dine from west t o east. There is also evidence that genetic distance between populations re flects geographic relationships, especially historical connectedness, as me asured by Pleistocene sea-crossing distances. At the microgeographic level, cave populations were heterogeneous and composed of diverse lineages sugge sting restricted local interchange. (C) 1998 The Linnean Society of London.