Possible and observed pathways to cosexuality and resexualization of U/V chromosomes from a unisexual haploid-dominant ancestor.The existence of sex chromosomes complicates the evolution of cosexuality (hermaphroditism). Four new genomic studies from haploid-dominant plants show commonalities and differences in mechanisms of the evolution of cosexuality, raising questions about the genetics of sexual dimorphism and the fate of cosexual lineages.