Sex reversal in nature
Out of 162 wild-caught adults, 152 were genotyped unambiguously (Table 1): using Method 1 we identified 89 normal males (XY), 41 normal females (XX), and 22 sex-reversed XX males, but no male-to-female sex reversals (Table 1). The overall XX/male ratio was 20% across wild populations, being two times higher than in the laboratory-raised animals (Table 1). The geographical distribution of sex reversals across capture sites is shown in Figure S5.
Among the wild-caught adults, XX/male ratio increased significantly with total anthropogenic land cover (Figure 1, Table 4). Similarly, XX/male ratio increased significantly with higher ”agricultural PC scores”, and it showed a marginally non-significant positive relationship with ”urban PC scores” (Figure 1, Table 4). Notably, sex reversals occurred even at the least anthropogenic sites (Figure 1), and XX/male ratio increased on average from 12.8% to 29.3% as total anthropogenic land cover increased from zero to 50% (Table 4).