Meeting Abstract
Mite harvestmen of the genus Austropurcellia (Opiliones: Cyphophthalmi: Pettalidae) have come to attention in recent years as a study system for understanding the biogeography of the Australian Wet Tropics biodiversity hotspot. The limited dispersal, excellent persistence, and ancient age of this lineage make it a particularly useful group for historical biogeographic study. Although phylogenetic relationships within this genus have been explored in recent years, previous studies did not achieve full taxonomic or biogeographic sampling across the genus. In addition, Austropurcellia divergence dates within the genus have not been calculated. Using recently collected specimens from species and subregions not represented in previous analyses, we sequenced one variable mitochondrial locus (cytochrome c oxidase subunit I, or COI) and two more conserved nuclear loci (18S and 28S rRNA). Phylogenetic trees were inferred using Bayesian methods in MrBayes. Maximum likelihood analyses were performed in RAxML and nodal support was estimated using bootstrap resampling. Relaxed molecular clock methods implemented in BEAST were used to determine dates of species divergence. We tested the hypothesis that rainforest contraction and fragmentation during the Pleistocene glacial cycles drove speciation within the genus, and also explored the taxonomic implications of the relationships we uncovered. Here we evaluate evidence for the hypothesis that rainforest contraction and fragmentation during Pleistocene glacial cycles is a driver of speciation within this paleoendemic arthropod genus. We also detail the taxonomic implications of the relationships recovered by our molecular tree topology.
