“…Copulatory plugs are a prominent feature in many internally fertilizing organisms, including nematodes (Barker, 1994;Palopoli et al, 2008), insects (Rogers et al, 2009), reptiles (Devine, 1975(Devine, , 1977Moreira and Birkhead, 2004), rodents (Voss, 1979;Dewsbury, 1984) and primates (Hartung and Dewsbury, 1978;Dixson and Anderson, 2002). Comparative studies suggest plugs evolved in the context of sperm competition, as a means for males to inhibit remating by females.…”