| 1. |
- Partridge, C, et al.
(författare)
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The effect of perceived female parasite load on post-copulatory male choice in a sex-role-reversed pipefish
- 2009
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 63, s. 345-354
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Tidskriftsartikel (refereegranskat)abstract
- The last several decades of research in behavioral ecology have resulted in a deeper appreciation of post-mating processes and sexual conflict in sexual selection. One of the most controversial aspects of sexual selection is cryptic mate choice. Here, we take advantage of male pregnancy in a sex-role-reversed pipefish (Syngnathus typhle) to quantify cryptic choice based on perceived parasite load and other sources of variance in female fitness. Studies have shown that S. typhle males preferentially mate with females with lower parasite loads and that a male's perception of female parasite load can be altered by tattooing females. We manipulated the apparent parasite load of females in controlled mating experiments to test the hypothesis that post-copulatory sexual selection is dependent on a male's perception of female parasite load in pipefish. Our results provided no evidence for cryptic male choice based on perceived female parasite load. However, we found evidence that eggs from larger females were more likely to result in viable offspring than eggs from smaller females and that the first female to mate with a male transferred more eggs per copulation on average. Overall, our results show that potential for post-copulatory sexual selection does exist in pipefish, but the male's perception of female parasite load does not play a major role in this process.
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| 2. |
- Wedell, N., et al.
(författare)
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Sexual conflict and life histories
- 2006
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472. ; 71:5, s. 999-1011
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Forskningsöversikt (refereegranskat)abstract
- There is burgeoning interest in the costs of mating and in how this leads to sex differences in the optimal mating rate. Here, we attempt to look beyond an exclusive focus on matings to examine the fundamental conflicts that arise out of the fact that sexual reproduction involves investment in offspring by typically unrelated individuals. Conflicts between mates stem from the ever present potential for individuals to reduce their investment relative to that of their sexual partner in order to seek alternative reproductive opportunities elsewhere. All aspects of life histories, the partitioning of time and energy into growth, survival and reproduction, are inextricably caught up in, and moulded by these conflicts of interest, the most profound expression of which is the differentiation between male and female types. This differentiation creates a new set of conflicts because alleles with positive effects on fitness when expressed in one sex may have negative fitness effects in the other. This type of conflict may influence the evolution of separate juvenile and adult life stages as in metamorphosis, although a major outstanding question is why sex limitation does not evolve more rapidly. We review the impact of conflicts of interest between males and females on all aspects of life history, revealing at least as much evidence for sexual conflict over life history traits such as investment in gametes and parental care as there is for conflicts over matings.
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