Female-female interactions and context-dependent plasticity of sexual selection

Project: Research project


Competition among females for access to mating opportunities and male mate choice are poorly studied so far. I will use two examples to study this field of sexual selection. Firstly, a native fish species, the common goby (Pomatoschistus microps), in which males defend nests as their territories and take care of their offspring. When nests are rare, females compete for access to males. The second example is an all-female fish, the amazon molly (Poecilia formosa), in which all descendants are natural clones of their mother. Nevertheless, to produce these daughters, females need sperm of closely related males to stimulate egg development. But the male’s genetic material is not passed on to the offspring. In this rare example, males should be choosy because mating with amazon mollies will not increase their reproductive success. It is an unsolved paradox in evolutionary biology how such sexual-asexual complexes may coexist.
Using the common goby as an example for competition among females, I am studying how competition influences mating decisions and how competition and mate choice are affected by environmental factors, resources, and social interactions. Furthermore, I am going to study the function of female sexual signals. The results will contribute to understanding the dynamics of sexual selection and sex roles.
Based upon the sexual-asexual species complex of the amazon molly, I will study how sexually and asexually reproducing, but sperm-dependent, organisms can coexist. Theory predicts that, within few generations, asexual organisms that only produce females should overrun sexual organisms that invest equally in the production of male and female offspring. I will investigate how choosy males, population dynamics, and spatial effects can explain the evolutionary stability of such systems.

Keywords: intrasexual competition, maintenance of sex, mate choice, population regulation, reproductive rates, sexual ornaments, sex ratio, sex role, sexual selection, social interactions.
Effective start/end date01/05/200730/04/2010

ID: 51111066