Genomic time‐series data show that gene flow maintains high genetic diversity despite substantial genetic drift in a butterfly species
| Autor: | Zachariah Gompert, Megan Brady, Amy Springer, Lauren K. Lucas, Samridhi Chaturvedi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Gene Flow
Genetic diversity Genetic Drift Genetic Variation Genomics Biology biology.organism_classification Gene flow Genetics Population Genetic drift Effective population size Evolutionary biology Genetic variation Genetics Animals Humans Rate of evolution Gene pool Butterflies Lycaeides Ecology Evolution Behavior and Systematics |
| Zdroj: | Molecular Ecology. 30:4991-5008 |
| ISSN: | 1365-294X 0962-1083 |
| DOI: | 10.1111/mec.16111 |
| Popis: | Effective population size affects the efficacy of selection, rate of evolution by drift, and neutral diversity levels. When species are subdivided into multiple populations connected by gene flow, evolutionary processes can depend on global or local effective population sizes. Theory predicts that high levels of diversity might be maintained by gene flow, even very low levels of gene flow, consistent with species long-term effective population size, but tests of this idea are mostly lacking. Here, we show thatLycaeidesbutterfly populations maintain low contemporary (variance) effective population sizes (e.g., ∼200 individuals) and thus evolve rapidly by genetic drift. Contemporary effective sizes were consistent with local census populations sizes. In contrast, populations harbored high levels of genetic diversity consistent with an effective population size several orders of magnitude larger. We hypothesized that the differences in the magnitude and variability of contemporary versus long-term effective population sizes were caused by gene flow of sufficient magnitude to maintain diversity but only subtly affect evolution on generational time scales. Consistent with this hypothesis, we detected low but non-trivial gene flow among populations. Furthermore, using population-genomic time-series data, we documented patterns consistent with predictions from this hypothesis, including a weak but detectable excess of evolutionary change in the direction of the mean (migrant gene pool) allele frequencies across populations, and consistency in the direction of allele frequency change over time. The documented decoupling of diversity levels and short-term change by drift inLycaeideshas implications for our understanding of contemporary evolution and the maintenance of genetic variation in the wild. |
| Databáze: | OpenAIRE |
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