Population variation in the fisher mitochondrial genome. The physical organization of the fisher mitochondrial genome is shown with the position of protein coding (blue), tRNA (red), rRNA (purple) and non-coding (colorless) regions indicated. The middle grey track shows the relative sequencing depth across all 40 genomes; scale runs from 1× to 8,000× and is log transformed. Colored bars on inside track show the location of the D-loop amplicon (yellow), the non-coding portion of the mitochondrion (green), and regions that were excluded from our analysis due to insufficient read depth (red). Orange ticks represent segregating sites with magenta ticks marking amino acid substitutions.