Abstract
Sexual selection, is instrumental in the evolution of conspicuous secondary sexual traits in the non-limiting sex of many animal species. It potentially also causes the evolution of reproductive isolation between diverging populations. Despite much progress in sexual selection theory in different branches of biology, a lack of communication between ecologists, behaviourists, geneticists and phylogeneticists has prevented a deeper understanding of its role in the origin of species. Recent models demonstrate that disruptive sexual selection, alone, even without disruptive natural selection, can be sufficient to cause speciation in sympatry, if the genetic architecture of preference and selected traits meets certain requirements, and if a new mutant can overcome the initial hurdle of mate finding by the rare morph. The aim of this programme is to determine the conditions for sympatric speciation by sexual selection in Lake Victoria haplochromine cichlid fish. In a multidisciplinary approach we study the fuII chain at evolutionary processes, leading from choosy mates to the origin of species diversity, and test whether sympatric speciation is possible in this system. To achieve this goal, close collaboration between several research groups is required. The proposed programme combines the Section of Animal Ecology's ongoing research with that of the Section Behavioural Biology and with the Section of Animal Behaviour of the University of Groningen. The latter two groups have a strong background in proximate behavioural mechanisms and physiological ecology. Together we will unravel (I) the functional basis and proximate mechanisms of disruptive sexual selection (II) the genetic architecture of, and developmental processes involved in the formation of mate preferences and traits, (III) the selection dynamics that affect the probability of invasion of a new trait or preference mutant.
Netherlands