 This work helped overturn the classic tenet that males are the “organized” sex and females the “default” sex.Today we recognize both sexes as organized and the question now becomes how the activation of a conserved network of genes leads to a binary response (ovary or testis).He is a pioneer in the relatively new field (actually rebirth) of phenotypic plasticity, or the process by which the environment induces different phenotypes from a given genotype.