Fig 7. Principal component analysis of parallel lake-stream differentiation SNPs.

PC1 separates migratory lake and resident stream ecotypes based on the SNPs found in parallel genomic islands of lake-stream differentiation shown in Figs 4B and 5(n = 75). Individuals with both lake-like and stream-like genomic signatures occur at stream sites S1a, S1b and S1, but lake ecotypes dominated at sites S1a and S1b, while stream ecotypes were most common at S1. Only stream ecotypes occurred at site S2 and only lake ecotypes at sites L1 and L2. Fill colors indicate the habitat in which individuals were caught, four stream habitat sites (orange) and two lake shore sites (black).