Poster, IBS 2015 - 7th International Conference of the International Biogeography Society, University of Bayreuth: 08.01.2015 - 12.01.2015
Population differentiation may be a first step towards divergence and potential speciation. The Crassulacean genus Aeonium on the Canary archipelago is a popular example for rapid species radiation on islands. However, while allopatric speciation among islands is well studied, the role of intra-island speciation by topography-driven or ecological differentiation among populations is still unclear. We studied population genetic patterns (ISSR variation) within two island-endemic Aeonium taxa of La Palma (one widespread generalist and one narrow specialist species) to identify potential spatial and/or ecological drivers of population differentiation and possible differences in species evolutionary potentials. Although only low spatial population structures were detected for both species, some clear landscape effects on population differentiation and likely species histories were observable. Also, ecological gradients (especially of precipitation-related variables) could be shown to correlate with allelic patterns of certain genetic loci, especially for the generalist species, indicating potential divergent selection pressures among populations of Aeonium species on the island scale.