Kelly B Klingler1, Joshua P Jahner1, Thomas L Parchman1,2, Chris Ray3, Mary M Peacock4,5. 1. Department of Biology, University of Nevada, Reno, 89557, USA. 2. Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV, 89557, USA. 3. Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA. 4. Department of Biology, University of Nevada, Reno, 89557, USA. mpeacock@unr.edu. 5. Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV, 89557, USA. mpeacock@unr.edu.
Abstract
BACKGROUND: Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. RESULTS: Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006-0.0009; θW = 0.0005-0.0007) relative to populations in California (π = 0.0014-0.0019; θW = 0.0011-0.0017) and the Rocky Mountains (π = 0.0025-0.0027; θW = 0.0021-0.0024), indicating substantial genetic drift in these isolated populations. Tajima's D was positive for all sites (D = 0.240-0.811), consistent with recent contraction in population sizes range-wide. CONCLUSIONS: Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.
BACKGROUND: Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. RESULTS: Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006-0.0009; θW = 0.0005-0.0007) relative to populations in California (π = 0.0014-0.0019; θW = 0.0011-0.0017) and the Rocky Mountains (π = 0.0025-0.0027; θW = 0.0021-0.0024), indicating substantial genetic drift in these isolated populations. Tajima's D was positive for all sites (D = 0.240-0.811), consistent with recent contraction in population sizes range-wide. CONCLUSIONS: Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.
Entities:
Keywords:
Alpine; Climate; Conservation; Genetic diversity; Genotyping-by-sequencing; Great basin; Metapopulation; Ochotona princeps; Rocky Mountains; Sierra Nevada
Authors: Joshua P Jahner; Daniel Gibson; Chava L Weitzman; Erik J Blomberg; James S Sedinger; Thomas L Parchman Journal: BMC Evol Biol Date: 2016-06-14 Impact factor: 3.260
Authors: Danielle A Schmidt; Matthew D Waterhouse; Bryson M F Sjodin; Michael A Russello Journal: Heredity (Edinb) Date: 2021-09-18 Impact factor: 3.821