Genome-wide markers reveal a complex evolutionary history involving divergence and introgression in the Abert's squirrel (Sciurus aberti) species group
Autor: | Helen K. Pigage, Jon C. Pigage, Jeremy M. Bono, Stephanie A. Prosser, Peter J. Wettstein |
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Rok vydání: | 2018 |
Předmět: |
0301 basic medicine
Genetic Markers Entomology Evolution Population Introgression Divergence with gene flow Admixture Biology DNA Mitochondrial Polymorphism Single Nucleotide Gene flow 03 medical and health sciences Sciurus aberti QH359-425 Animals education Hybridization Ecology Evolution Behavior and Systematics Hybrid education.field_of_study Likelihood Functions Principal Component Analysis Genome Geography Ponderosa pine Genetic Variation Sciuridae Mitochondrial capture Reproductive isolation Cytochromes b biology.organism_classification Biological Evolution Mitochondria Phylogeography 030104 developmental biology Haplotypes Evolutionary biology Mito-nuclear discordance Research Article |
Zdroj: | BMC Evolutionary Biology BMC Evolutionary Biology, Vol 18, Iss 1, Pp 1-17 (2018) |
ISSN: | 1471-2148 |
Popis: | Background Genetic introgression between divergent lineages is now considered more common than previously appreciated, with potentially important consequences for adaptation and speciation. Introgression is often asymmetric between populations and patterns can vary for different types of loci (nuclear vs. organellar), complicating phylogeographic reconstruction. The taxonomy of the ecologically specialized Abert’s squirrel species group has been controversial, and previous studies based on mitochondrial data have not fully resolved the evolutionary relationships among populations. Moreover, while these studies identified potential areas of secondary contact between divergent lineages, the possibility for introgression has not been tested. Results We used RAD-seq to unravel the complex evolutionary history of the Abert’s squirrel species group. Although some of our findings reinforce inferences based on mitochondrial data, we also find significant areas of discordance. Discordant signals generally arise from previously undetected introgression between divergent populations that differentially affected variation at mitochondrial and nuclear loci. Most notably, our results support earlier claims (disputed by mitochondrial data) that S. aberti kaibabensis, found only on the north rim of the Grand Canyon, is highly divergent from other populations. However, we also detected introgression of S. aberti kaibabensis DNA into other S. aberti populations, which likely accounts for the previously inferred close genetic relationship between this population and those south of the Grand Canyon. Conclusions Overall, the evolutionary history of Abert’s squirrels appears to be shaped largely by divergence during periods of habitat isolation. However, we also found evidence for interbreeding during periods of secondary contact resulting in introgression, with variable effects on mitochondrial and nuclear markers. Our results support the emerging view that populations often diversify under scenarios involving both divergence in isolation and gene flow during secondary contact, and highlight the value of genome-wide datasets for resolving such complex evolutionary histories. Electronic supplementary material The online version of this article (10.1186/s12862-018-1248-4) contains supplementary material, which is available to authorized users. |
Databáze: | OpenAIRE |
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