PT  - JOURNAL ARTICLE
AU  - Scott Hotaling
AU  - Daniel H. Shain
AU  - Shirley A. Lang
AU  - Robin K. Bagley
AU  - Lusha M. Tronstad
AU  - David W. Weisrock
AU  - Joanna L. Kelley
TI  - Long-distance dispersal, ice sheet dynamics, and mountaintop isolation underlie the genetic structure of glacier ice worms
AID  - 10.1101/463521
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 463521
4099  - http://biorxiv.org/content/early/2018/11/08/463521.short
4100  - http://biorxiv.org/content/early/2018/11/08/463521.full
AB  - Disentangling the contemporary and historical factors underlying the spatial distributions of species is a central goal of biogeography. For species with broad distributions but little capacity to actively disperse, disconnected geographic distributions highlight the potential influence of passive, long-distance dispersal (LDD) on their evolutionary histories. However, dispersal alone cannot completely account for the biogeography of any species, and other factors–e.g., habitat suitability, life history–must also be considered. North American ice worms (Mesenchytraeus solifugus) are glacier-obligate annelids that inhabit coastal North American glaciers from Oregon to Alaska. Previous studies identified a complex biogeographic history for ice worms, with evidence for genetic isolation, unexpectedly close relationships among geographically disjunct lineages, and evidence for contemporary migration across large (>1,500 km) areas of unsuitable habitat. In this study, we collected genome-scale sequence data for most of the known ice worm range. We found support for a deep divergence between populations along the Pacific Coast and the inland flanks of the Coast Mountains (mean FST = 0.60) as well as support for LDD from Alaska to Vancouver Island, perhaps mediated by migrating birds. Our results highlight the power of genomic data for disentangling complex biogeographic patterns, including the presence of LDD.