Small fish, large river: Surprisingly minimal genetic structure in a dispersal-limited, habitat specialist fish
| Autor: | Brooke A. Washburn, Rebecca E. Blanton, Mollie F. Cashner |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Range (biology) Population Species distribution 010603 evolutionary biology 01 natural sciences 03 medical and health sciences lcsh:QH540-549.5 education Ecology Evolution Behavior and Systematics 030304 developmental biology Nature and Landscape Conservation Isolation by distance Original Research stepping‐stone dispersal linear river system 0303 health sciences education.field_of_study Ecology biology patchy habitat biology.organism_classification isolation‐by‐distance Etheostoma dispersal‐limited small spatial scale Habitat Genetic structure Biological dispersal lcsh:Ecology |
| Zdroj: | Ecology and Evolution Ecology and Evolution, Vol 10, Iss 4, Pp 2253-2268 (2020) |
| ISSN: | 2045-7758 |
| Popis: | Genetic connectivity is expected to be lower in species with limited dispersal ability and a high degree of habitat specialization (intrinsic factors). Also, gene flow is predicted to be limited by habitat conditions such as physical barriers and geographic distance (extrinsic factors). We investigated the effects of distance, intervening pools, and rapids on gene flow in a species, the Tuxedo Darter (Etheostoma lemniscatum), a habitat specialist that is presumed to be dispersal‐limited. We predicted that the interplay between these intrinsic and extrinsic factors would limit dispersal and lead to genetic structure even at the small spatial scale of the species range (a 38.6 km river reach). The simple linear distribution of E. lemniscatum allowed for an ideal test of how these factors acted on gene flow and allowed us to test expectations (e.g., isolation‐by‐distance) of linearly distributed species. Using 20 microsatellites from 163 individuals collected from 18 habitat patches, we observed low levels of genetic structure that were related to geographic distance and rapids, though these factors were not barriers to gene flow. Pools separating habitat patches did not contribute to any observed genetic structure. Overall, E. lemniscatum maintains gene flow across its range and is comprised of a single population. Due to the linear distribution of the species, a stepping‐stone model of dispersal best explains the maintenance of gene flow across its small range. In general, our observation of higher‐than‐expected connectivity likely stems from an adaptation to disperse due to temporally unstable and patchy habitat. We examine whether physical obstacles and geographic distance influence genetic structure in a presumably dispersal‐limited, habitat specialist riverine fish. We found minimal levels of genetic structure associated with rapids and distance. So, we conclude that there are minimal filters to gene flow in this endangered species and that higher‐than‐expected connectivity likely stems from an adaptation to disperse due to temporally unstable and patchy habitats. |
| Databáze: | OpenAIRE |
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