“…Furthermore, the coexistence of multiple sex determining loci in a number of species (e.g., cichlids, housefly, zebrafish, seabass) suggests that multifactorial sex determination need not be unstable, provided the sex ratio is balanced (Liew et al, ; Meisel et al, ; Moore & Roberts, ; Roberts et al, ; Vandeputte, Dupont‐Nivet, Chavanne, & Chatain, ; Wilson et al, ). Because sex operates as a threshold trait in which female or male development is triggered when genetic and/or environmental cues surpass some level (Bulmer & Bull, ; Roff, ), the presence of multiple sex determining loci may not necessarily indicate that a system is undergoing a sex chromosome turnover (Beukeboom & Perrin, ; Perrin, ; Rodrigues et al, ).…”