How microevolutionary processes that occur at the population level translate into the macroevolutionary patterns of diversification found in nature is a major question in evolutionary biology. Linking these microevolutionary forces and macroevolutionary transitions, however, is not an easy task, given the very different geographic and temporal scales at which the processes occur and the patterns are inferred. Here, we take advantage of an unusual natural system, the species Salamandra salamandra, to study at the population level one of these macroevolutionary transitions, the evolution of a new reproductive mode in a species.
Viviparity, the laying of fully formed juveniles, has independently evolved in almost all the vertebrate lineages, but with very different prevalence among groups. We here aim to use the fire salamander (Salamandra salamandra) as a model system since this species displays an exceptional diversity of reproductive modes. The general mode is ovoviviparity, where females give birth to many small, aquatic larvae, whereas the second, viviparity, is a phylogenetically derived reproductive strategy. Furthermore, ovoviviparous and viviparous populations occur along the continuous range of the species, and contact areas among populations with different reproductive modes occur. This constitutes an unusual natural laboratory in which to study the evolution of the novelty at the population level.
This proposal combines front-line tools to study genetic, morphologic, ecological and physiologic differentiation between viviparous and ovoviviparous populations in S. salamandra. Although ambitious, we capitalize on the research team experience on the study organism and the expertise on the different research tools and techniques that will be employed. The research plan is divided in five tasks organized to take advantage from the distinct skills of the team members. Besides partial results that will be generated in each task, the added value of the proposal is to provide a new analytical framework with which to distil an evolutionary scenario for the evolution of viviparity in the species. This framework will constitute an integrative tool for the study of the mechanistic forces behind the evolution of a new trait, bridging the gap between the study of microevolutionary processes and macroevolutionary transitions.
Funding agency: Fundação para a Ciência e Tecnologia /Programa COMPETE
Budget: 79 336€
Project Code: PTDC/BIA-EVF/3036/2012
Principal investigator: G Velo-Antón