Meeting Abstract

71.3  Sunday, Jan. 6  Phylogeography of the mite harvestman Aoraki denticulata in the South Island of New Zealand BOYER, Sarah L.*; BAKER, Jessica M.; GIRIBET, Gonzalo; Macalester College; Harvard University; Harvard University boyer@macalester.edu

Aoraki denticulata (Arachnida, Opiliones, Cyphophthalmi, Pettalidae), is a widespread “mite harvestman” endemic to the South Island of New Zealand. Using a 785 bp region of the gene cytochrome c oxidase I, we investigated the phylogeography and demographic history of A. denticulata in the first genetic population-level study within Opiliones. An extraordinarily high degree of genetic diversity was discovered in A. denticulata, with average uncorrected p-distances between populations as high as 19.2%. AMOVA, average numbers of pairwise differences, and pairwise FST values demonstrated a significant amount of genetic diversity both within and between populations of this subspecies. Phylogenetic analysis of the data set revealed many well-supported groups within A. denticulata, generally corresponding to clusters of specimens from single populations with short internal branches, but separated by long branches from individuals from other populations. These results indicate a species within which very little genetic exchange occurs between populations, a result consistent with the idea that Cyphophthalmi ("mite harvestmen") are poor dispersers. Past geologic events such as the uplift of the Southern Alps and Pleistocene glaciation may have contributed to the deep genetic divergences observed between sampling localities; additionally, the high divergence within populations of A. denticulata suggests that the rate of COI evolution may be accelerated in this taxon.