Genomic divergence between SpanishLittorina saxatilisecotypes unravels limited admixture and extensive parallelism associated with population history
| Autor: | Juan Galindo, Tony Kess, Elizabeth G. Boulding |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine Littorina saxatilis Population Genomics RAD sequencing 010603 evolutionary biology 01 natural sciences Ecological speciation Gene flow 03 medical and health sciences lcsh:QH540-549.5 ecological speciation genomics 14. Life underwater education Ecology Evolution Behavior and Systematics Nature and Landscape Conservation Local adaptation Hybrid parallelism education.field_of_study Ecology Ecotype biology marine snail biology.organism_classification 030104 developmental biology Evolutionary biology lcsh:Ecology local adaptation |
| Zdroj: | Ecology and Evolution, Vol 8, Iss 16, Pp 8311-8327 (2018) |
| ISSN: | 2045-7758 |
| DOI: | 10.1002/ece3.4304 |
| Popis: | The rough periwinkle, Littorina saxatilis, is a model system for studying parallel ecological speciation in microparapatry. Phenotypically parallel wave‐adapted and crab‐adapted ecotypes that hybridize within the middle shore are replicated along the northwestern coast of Spain and have likely arisen from two separate glacial refugia. We tested whether greater geographic separation corresponding to reduced opportunity for contemporary or historical gene flow between parallel ecotypes resulted in less parallel genomic divergence. We sequenced double‐digested restriction‐associated DNA (ddRAD) libraries from individual snails from upper, mid, and low intertidal levels of three separate sites colonized from two separate refugia. Outlier analysis of 4256 SNP markers identified 34.4% sharing of divergent loci between two geographically close sites; however, these sites each shared only 9.9%–15.1% of their divergent loci with a third more‐distant site. STRUCTURE analysis revealed that genotypes from only three of 166 phenotypically intermediate mid‐shore individuals appeared to result from recent hybridization, suggesting that hybrids cannot be reliably identified using shell traits. Hierarchical AMOVA indicated that the primary source of genomic differentiation was geographic separation, but also revealed greater similarity of the same ecotype across the two geographically close sites than previously estimated with dominant markers. These results from a model system for ecological speciation suggest that genomic parallelism is affected by the opportunity for historical or contemporary gene flow between populations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text