Asexual clones could quickly dominate populations by dispensing with male production and mating (Bell, 1982). And yet, most known species engage in sexual reproduction, at least sporadically, which has led to many hypotheses on the spread and maintenance of sex (Hartfield & Keightley, 2012). Recent studies have helped to restrict the range of plausible mechanisms selecting for sex given variation in reproductive mode (Archetti, 2022;Brandeis, 2018;Sharp & Otto, 2016), but there remains significant uncertainty about the selective agents operating on reproductive mode under natural conditions (Neiman et al., 2018;Tilquin & Kokko, 2016). Natural selection is ultimately caused by ecological or environmental factors (MacColl, 2011), so accounting for such factors is crucial for any comprehensive theory of sexual reproduction.Yet, the relative fitness of sex under certain environmental conditions depends on its genetic mechanisms. Currently, the most supported mechanisms are (reviewed by Archetti, 2022;Hartfield