Of Molecules and Sex

Scholars have written tomes on the subject of variation in animal approaches to sex/reproduction (see, for example, Bagemihl, 1999; Bell, 2008). There are lizards (and lots of insects) that don’t use males at all (Crews & Fitzgerald, 1980). Instead females kick-start embryonic development without fertilization, using a process called parthenogenesis (literally “virgin birth”). There are insects that have three sexes, ¹ and there are fish that have four different types of sexual beings.