Sexual selection when fertilization is not guaranteed |
| |
Authors: | Kokko Hanna Mappes Johanna |
| |
Institution: | Laboratory of Ecological and Evolutionary Dynamics, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland. hanna.kokko@helsinki.fi |
| |
Abstract: | Abstract Much of the theory of sexual selection assumes that females do not generally experience difficulties getting their eggs fertilized, yet sperm limitation is occasionally documented. How often does male limitation form a selection for female traits that improve their mating rate? The question is difficult to test, because if such traits evolve to be efficient, sperm limitation will no longer appear to be a problem to females. Here, we suggest that changes in choosiness between populations, and in particular between virgin and mated females, offer an efficient way to test this hypothesis. We model the “wallflower effect,” that is, changes in female preferences due to time and mortality costs of remaining unmated (for at least some time). We show that these costs cause adaptive reductions of female choice, even if mate encounter rates appear high and females only rarely end their lives unfertilized. We also consider the population consequences of plastic or fixed mate preferences at different mate encounter rates. If mate choice is plastic, we confirm earlier verbal models that virgins should mate relatively indiscriminately, but plastic increase of choosiness in later matings can compensate and intensify sexual selection on the male trait, particularly if there is last male sperm precedence. Plastic populations will cope well with unusual conditions: eagerness of virgins leads to high reproductive output and a relaxation of sexual selection at low population densities. If females lack such plasticity, however, population‐wide reproductive output may be severely reduced, whereas sexual selection on male traits remains strong. |
| |
Keywords: | Female choice multiple mating phenotypic plasticity population consequences of sexual selection sequential mate choice sexual selection sperm limitation virgins |
本文献已被 PubMed 等数据库收录! |
|