Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fish
Abstract 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...
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| Format: | Article |
| Language: | English |
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Wiley
2020-02-01
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| Series: | Ecology and Evolution |
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| Online Access: | https://doi.org/10.1002/ece3.6064 |
| _version_ | 1818429994845601792 |
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| author | Brooke A. Washburn Mollie F. Cashner Rebecca E. Blanton |
| author_facet | Brooke A. Washburn Mollie F. Cashner Rebecca E. Blanton |
| author_sort | Brooke A. Washburn |
| collection | DOAJ |
| description | Abstract 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. |
| first_indexed | 2024-12-14T15:26:22Z |
| format | Article |
| id | doaj.art-19007711af9947239fb24bc395ad7057 |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-12-14T15:26:22Z |
| publishDate | 2020-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-19007711af9947239fb24bc395ad70572022-12-21T22:56:00ZengWileyEcology and Evolution2045-77582020-02-011042253226810.1002/ece3.6064Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fishBrooke A. Washburn0Mollie F. Cashner1Rebecca E. Blanton2Department of Biology Center of Excellence for Field Biology Austin Peay State University Clarksville TN USADepartment of Biology Center of Excellence for Field Biology Austin Peay State University Clarksville TN USADepartment of Biology Center of Excellence for Field Biology Austin Peay State University Clarksville TN USAAbstract 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.https://doi.org/10.1002/ece3.6064dispersal‐limitedisolation‐by‐distancelinear river systempatchy habitatsmall spatial scalestepping‐stone dispersal |
| spellingShingle | Brooke A. Washburn Mollie F. Cashner Rebecca E. Blanton Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fish Ecology and Evolution dispersal‐limited isolation‐by‐distance linear river system patchy habitat small spatial scale stepping‐stone dispersal |
| title | Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fish |
| title_full | Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fish |
| title_fullStr | Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fish |
| title_full_unstemmed | Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fish |
| title_short | Small fish, large river: Surprisingly minimal genetic structure in a dispersal‐limited, habitat specialist fish |
| title_sort | small fish large river surprisingly minimal genetic structure in a dispersal limited habitat specialist fish |
| topic | dispersal‐limited isolation‐by‐distance linear river system patchy habitat small spatial scale stepping‐stone dispersal |
| url | https://doi.org/10.1002/ece3.6064 |
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