Abstract
Sperm competition may select for male reproductive traits that influence female mating or oviposition rate. These traits may induce fitness costs to the female; however, they may be costly for the males as well as any decrease in female fitness also affects male fitness. Male adaptations to sperm competition manipulate females by altering not only female behaviour or physiology, but also female morphology. In orb-weaving spiders, mating may entail mutilation of external structures of the female genitalia, which prevents genital coupling with subsequent males. Here, we present a game theoretical model showing that external female genital mutilation is favoured even under relatively high costs of mutilation, and that it is favoured by a high number of mate encounters per female and last-male sperm precedence.
Highlights
Males may evolve traits that shift the remating or oviposition rate of the female from the female’s optimum towards their own due to selection on competitive fertilization success [1,2]
Our model predicts that the evolution of external female genital mutilation (EFGM) can evolve even under relatively high costs of mutilation (α), and that it is favoured by a high number of mate encounters per female (n) and ancestral last-male sperm precedence
There is currently no evidence for EFGM reducing female fitness, this absence of costs may be the result of selection on females for reducing such costs [1,2,17]
Summary
Males may evolve traits that shift the remating or oviposition rate of the female from the female’s optimum towards their own due to selection on competitive fertilization success [1,2]. Defensive adaptations to sperm competition include mate guarding, copulatory plugs, manipulative seminal fluids and internal genital damage. These adaptations can manipulate the female by altering her behaviour or physiology, and her genital anatomy [3]. Examples of male-inflicted damages to female genitalia have been documented in numerous taxa, especially among arthropods [4,5] Most of these genital damages are inflicted internally by the male intromittent organ, and it is debated how these harmful traits have evolved [6,7,8]. It has been described that males inflict external damage to the female genitalia in two species of orb-weaving spiders as a defensive adaptation to sperm competition [9,10]. We present a game theoretical model to explore the conditions under which EFGM can evolve and be maintained
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
