Allele frequency distribution plots/Allele frequencies for L. braziliensis M2904 and L. mexicana U1103 were inferred from filtered Samtools pile-up results. For each predicted heterozygous site, the proportion of each of the four sites over the total read depth for the site was determined and rounded to the second decimal place. Allele frequencies were binned into categories from 0.1 to 1.0, and counts for each allele frequency were plotted in R for each chromosome. In order to facilitate cross-comparison of chromosomes, counts for each category were normalized by dividing the count for each allele frequency category by the sum of all frequency category counts for that chromosome. Arithmetic means were calculated for each ‘‘somy’’ group and plotted in R, along with scatterplots of normalized allele frequency counts for every chromosome in this group. Plots were grouped according to their number of peaks. Chromosome 14 from L. braziliensis did not fit any of these profiles and was excluded from the analysis.