Figure 1

Distribution of sex ratios as regulated by naturally occurring Y chromosomes. Sex ratios were measured in offspring sired by male genotypes isogenic to w Dox; nt; nmy [sim1427], except for the introgressed Y chromosomes. Y chromosomes were independently derived from 78 isofemale D. simulans stocks, among which 44 stocks originated from a single locality in Massachusetts and 34 stocks were of global origins.