Wednesday, July 05, 2006

PhD Proposal I: University of Zurich

A while ago, I promised I'd post the abstract of the proposal I submitted to the Forschungskredit Kommittee at the University of Zurich. So, here it is.

Body size is an important phenotypic trait, as it influences a wide range of life-history parameters. Patterns of body size variation, such as Bergmann’s rule, suggest a role for natural selection in shaping this trait. Sexual selection and interactions between sexual and natural selection are also potential forces acting on body size and other morphological traits, and may explain patterns of variation better than natural selection alone. Syngnathid fishes are unique among teleosts in the degree of male parental care and the diversity of mating systems and sexual selection regimes. They provide an ideal model for studying the interactions between sexual and natural selection and the effects of these forces on the evolution of selected traits. I propose to conduct experiments examining sexual and natural selection in the seahorse Hippocampus abdominalis, and to examine the genetic architecture of phenotypic evolution. I will construct a genetic linkage map for this species, using microsatellite markers and incorporating phenotypic variation in body size and other morphological traits, and genotypic variation in male pregnancy genes, in co-operation with Kai Stölting and Prof. Wilson. To study the constraints on sexual selection and interactions with natural selection, I will conduct two series of experiments. The first series will determine the mating system of H. abdominalis, which strongly influences the strength of sexual selection. Behavioural studies of this and other seahorse species have suggested a mating system of strict lifetime monogamy, which I aim to test using molecular genetic methods. The second series of experiments will test the mating preferences of this species, to examine the strength and direction of sexual selection, under two temperature conditions. Seahorses have extreme male parental investment, but do not appear to show sex-role reversal. Therefore, I expect female preferences to be stronger than male preferences, and to change with temperature. The second series will identify other morphological traits that are under sexual selection, which can then be studied in a genetic architecture context using the genetic linkage map. My studies of mating system, mating preference, and genetic architecture will contribute to understanding of this species as well as testing and contributing to theories of sexual and natural selection.

This is the less-than-2500-characters abstract for a 10-page proposal, so obviously it's a little abbreviated. But perhaps it gives a taste of what I hope to do starting in January 2007.

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