[legodt]

Very good point, but in nature a binary of sexes is not absolute. You are applying the artificial gender binary to sexes, which in nature are often messy and unclear. This can range from species that change sex organs as they mature, take on different reproductive roles dependent on situations, and even manifests in a statistically significant amount of humans born with both sets of reproductive organs. Assuming two sexes, then going on to conflate that with gender, demonstrates only an elementary understanding of reproductive biology.