title: Genomic data reveal ancient microendemism in forest scorpions across the California Floristic Province.
abstract: The California Floristic Province (CFP) in western North America is a globally significant biodiversity hotspot. Elucidating patterns of endemism and the historical drivers of this diversity has been an important challenge of comparative phylogeography for over two decades. We generated phylogenomic data using ddRADseq to examine genetic structure in Uroctonus forest scorpions, an ecologically restricted and dispersal-limited organism widely distributed across the CFP north to the Columbia River. We coupled our genetic data with species distribution models (SDMs) to determine climatically suitable areas for Uroctonus both now and during the Last Glacial Maximum. Based on our analyses, Uroctonus is composed of two major genetic groups that likely diverged over 2 million years ago. Each of these groups itself contains numerous genetic groups that reveal a pattern of vicariance and microendemism across the CFP. Migration rates among these populations are low. SDMs suggest forest scorpion habitat has remained relatively stable over the last 21 000 years, consistent with the genetic data. Our results suggest tectonic plate rafting, mountain uplift, river drainage formation and climate-induced habitat fragmentation have all likely played a role in the diversification of Uroctonus. The intricate pattern of genetic fragmentation revealed across a temporal continuum highlights the potential of low-dispersing species to shed light on small-scale patterns of biodiversity and the underlying processes that have generated this diversity in biodiversity hotspots.
authors.affiliation: Department of Biology and Burke Museum of Natural History and Culture, University of Washington, Box 351800, Seattle, WA, 98195-1800, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Bryson
authors.affiliation: Department of Entomology, California Academy of Sciences, 55 Music Concourse Drive, Golden Gate Park, San Francisco, CA, 94118, USA.
authors.forename: Warren E
authors.initials: WE
authors.lastname: Savary
authors.affiliation: Department of Biology, Occidental College, 1600 Campus Road, Los Angeles, CA, 90041, USA.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Zellmer
authors.affiliation: 41410 NW 12th Street, Corvallis, OR, 97330, USA.
authors.forename: R Bruce
authors.initials: RB
authors.lastname: Bury
authors.affiliation: Department of Biology, Occidental College, 1600 Campus Road, Los Angeles, CA, 90041, USA.|Moore Laboratory of Zoology, Occidental College, 1600 Campus Road, Los Angeles, CA, 90041, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: McCormack
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002140:California; D065928:Forests; D005828:Genetics, Population; D023281:Genomics; D010802:Phylogeny; D012605:Scorpions / Q000145:classification / Q000235:genetics*
keywords: California Floristic Province; RADseq; Uroctonus; arachnid; dispersal; endemism; phylogeography; species distribution model