Determining the necessity and mechanisms of assortative mating in an adaptively diverging salamander population (Salamandra salamandra)

• Applicant: Professorin Dr. Barbara Caspers
• Subject Area: Evolution, Anthropology
• Term: from 2009 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 135720878

Assortative mating – preferred mating with the own type - is a central theme within the concept of adaptive speciation, as it is required to prevent geneflow between differentially adapted types. Recent studies on a population of the terrestrial fire salamander (Salamandra salamandra) in Germany (the Kottenforst near Bonn) suggest that the adaptation to different reproduction habitats within the small forest initiated a process of adaptive divergence under sympatric conditions. This proposal is aimed to analyse the mechanisms and necessity of assortative mating in this system. We will investigate the degree of assortative mating under seminatural condition, in order to find existing isolation mechanisms. As odour cues are widely used by salamanders for intraspecific communication and sexual recognition, we will analyse in behavioural/genetic based mate-choice experiments whether odour cues are involved in habitat dependent assortative mating. Further, by applying a bioassay approach in combination with high performance liquid chromatography linked with mass spectrometry (HPLC/MS) we are going to analyse and identify involved odour substances chemically. In order to correlate and interpret the results from the assortative mating analysis in a natural context we will determine the degree of sympatry of adaptive types by analysing dispersal, home range size and movement patterns of adult individuals across the Kottenforst over several years. This detailed study is an outstanding approach to analyse mechanisms of assortative mating in a natural setting of an adaptively diverging terrestrial vertebrate species.

• DFG Programme: Research Grants
• Host: Professor Dr. Fritz Trillmich