Gene Pool Boundaries for the Yosemite Toad (Anaxyrus canorus) Reveal Asymmetrical Migration Within Meadow Neighborhoods

Frontiers in Conservation Science

Andres Aguilar¹  Andrew J. Bohonak²  Paul A. Maier³  Steven M. Ostoja⁴  Amy G. Vandergast⁵ 

[1] Department of Biological Sciences, California State University, Los Angeles, Los Angeles, CA, United States;Department of Biology, San Diego State University, San Diego, CA, United States;FamilyTreeDNA, Gene by Gene, Houston, TX, United States;U.S. Department of Agriculture (USDA) California Climate Hub, Agricultural Research Service, John Muir Institute of the Environment, University of California, Davis, Davis, CA, United States;U.S. Geological Survey, Western Ecological Research Center, San Diego Field Station, San Diego, CA, United States;

关键词: population genetics;    conservation;    asymmetrical migration;    source-sink dynamics;    isolation-by-distance;    amphibian conservation;   

DOI  :  10.3389/fcosc.2022.851676

来源: DOAJ

【 摘 要 】

The Yosemite toad (Anaxyrus [Bufo] canorus) is a federally threatened species of meadow-specializing amphibian endemic to the high-elevation Sierra Nevada Mountains of California. The species is one of the first amphibians to undergo a large demographic collapse that was well-documented, and is reputed to remain in low abundance throughout its range. Recent phylogeographic work has demonstrated that Pleistocene toad lineages diverged and then admixed to differing extents across an elevational gradient. Although lineage divisions may have significant effects on evolutionary trajectories over large spatial and temporal scales, present-day population dynamics must be delineated in order to manage and conserve the species effectively. In this study, we used a double-digest RADseq dataset to address three primary questions: (1) Are single meadows or neighborhoods of nearby meadows most correlated with population boundaries? (2) Does asymmetrical migration occur among neighborhoods of nearby meadows? (3) What topographic or hydrological variables predict such asymmetrical migration in these meadow neighborhoods? Hierarchical STRUCTURE and AMOVA analyses suggested that populations are typically circumscribed by a single meadow, although 84% of meadows exist in neighborhoods of at least two meadows connected by low levels of migration, and over half (53%) of neighborhoods examined display strong asymmetrical migration. Meadow neighborhoods often contain one or more large and flat “hub” meadows that experience net immigration, surrounded by smaller and topographically rugged “satellite” meadows with net emigration. Hubs tend to contain more genetic diversity and could be prioritized for conservation and habitat management and as potential sources for reestablishment efforts.

【 授权许可】

Unknown