allele frequency was calculated in genodive

This variation complicates their usefulness as proxies of the ancestors of freshwater populations. Marine stickleback are structured into phenotypically and genetically distinct populations that have been evolving as freshwater stickleback evolved. Comparisons to a freshwater population demonstrated that candidate loci for freshwater adaptation varied depending on the choice of marine populations. Plate number, Eda, body shape, and candidate loci showed evidence of being under selection in the marine environment. Stickleback were divided into five genetic clusters, with a single cluster comprising stickleback from Washington to Alaska. We sequenced > 5800 variant loci in over 250 marine stickleback from eight locations extending from Alaska to California, and phenotyped them for platedness and body shape. To what extent are marine stickleback good proxies of the ancestral condition? Results

Marine threespine stickleback ( Gasterosteus aculeatus) have colonized freshwater environments along the Pacific coast of North America, but have also persisted in the marine environment. However, evolution and demography in these “contemporary ancestors” can complicate inferences about the source (standing genetic variation, de novo mutation) and pace of adaptive divergence. Such “contemporary ancestors” can be used to demonstrate the effects of selection by comparing phenotypic and genetic divergence between the derived population and their extant ancestors. Populations that have repeatedly colonized novel environments are useful for studying the role of ecology in adaptive divergence – particularly if some individuals persist in the ancestral habitat.

Allele frequency was calculated in genodive