Experimentally induced intrasexual mating competition and sex‐specific evolution in female and male nematodes. (1st October 2020)

• Record Type: Journal Article
• Authors: Stångberg, Josefine; Immonen, Elina; Moreno, Pilar Puimedon; Bolund, Elisabeth
• Is Part Of: Journal of evolutionary biology. Volume 33:Number 12(2020)
• Page Start: 1677
• Page End: 1688
• Publication Date: 2020-10-01
• Subjects: Caenorhabditis remanei -- experimental evolution -- intralocus sexual conflict -- life history -- sexual dimorphism -- trade‐off; Evolution (Biology) -- Periodicals; Biology -- Periodicals; 576.8
• DOI: 10.1111/jeb.13706
• Languages: English
• ISSNs: 1010-061X

Abstract

Abstract: Sexual dimorphism in life history traits and their trade‐offs is widespread among sexually reproducing animals and is strongly influenced by the differences in reproductive strategies between the sexes. We investigated how intrasexual competition influenced specific life history traits, important to fitness and their trade‐offs in the outcrossing nematode Caenorhabditis remanei . Here, we altered the strength of sex‐specific selection through experimental evolution with increased potential for intrasexual competition by skewing the adult sex ratio towards either females or males (1:10 or 10:1) over 30 generations and subsequently measured the phenotypic response to selection in three traits related to fitness: body size, fecundity and tolerance to heat stress. We observed a greater evolutionary change in females than males for body size and peak fitness, suggesting that females may experience stronger net selection and potentially harbour higher amounts of standing genetic variance compared to males. Our study highlights the importance of investigating direct and indirect effects of intrasexual competition in both sexes in order to capture sex‐specific responses and understand the evolution of sexual dimorphism in traits expressed by both sexes. Abstract : Sex‐specific evolution of peak fitness in response to skewed sex ratios, with the ancestral (ANC) population compared to female‐biased (FB) and male‐biased (MB) treatment populations after 30 generations of experimental evolution in Caenorhabditis remanei . We found a significant interaction between sex and treatment, indicating sex‐specific evolutionary responses in peak fitness (λpeak ). Thus, the increased potential for intrasexual competition in the common sex in each treatment leads to opposite responses in the two sexes.