Data for: Genomic variation across Chinook salmon populations reveals effects of a duplication on migration alleles and supports fine scale structure

Distribution of ecotypic variation in natural populations is influenced by neutral and adaptive evolutionary forces that are challenging to disentangle without understanding of genomic architecture for phenotypic traits. This study provides a high-resolution portrait of genomic variation in Chinook salmon (Oncorhynchus tshawytscha) with emphasis on a region of major effect for ecotypic variation in migration timing. With a filtered dataset of ~13 million SNPs from low coverage whole genome resequencing of 53 populations (3,566 barcoded individuals), we contrasted patterns of genomic variation within and among major lineages and examined the extent of a selective sweep at a major effect region underlying migration timing (GREB1L/ROCK1). Allele frequency variation in GREB1L/ROCK1 was highly correlated with mean migration timing for early- and late-run populations within each of the lineages (r2 between 0.58–0.95; P < 0.001). However, the extent of selection within the genomic region co..., ,