INVASOMICS · Adaptive plasticity as a key for invasion success in disturbed ecosystems

Invasive species are a major constituent of global change, threaten local biodiversity, ecosystem services, and cause serious economic damage. Invasion science has tried to discern the factors that determine whether a non-native population will become invasive or not. Invasive populations are usually depleted in genetic diversity, creating the so-called 'invasion paradox' because traditional perspectives consider high genetic variation to be crucial for rapid adaptation to novel environments. Recent theoretical advances trying to solve this paradox propose that contemporary pre-adaptation to human-altered habitats within the native range or during the transport stage in the introduction can promote invasions. If this is true, introduced populations will exhibit increased adaptive tolerance to a stressor associated with transport, e.g. eutrophication, contributing to their success in the recipient environment. The aim of this project is to understand adaptive mechanisms that promote invasion success in widespread invasive freshwater vertebrate and invertebrate species. I will study the phenotypic differentiation of wild populations of the eastern mosquitofish in an eutrophication gradient, complemented with laboratory ecotoxicology experiments, both in the native (Florida) and invasive (Spain) ranges of the model species. This intraspecific comparison will be supported by the interspecific study of 3 sympatric freshwater amphipod species in Germany to assess potential competitive shifts in the invasive ones stemming from higher tolerances to eutrophication. Including natural populations with such particularly well described invasion histories will show why some populations become invaders and others do not. Current developments in molecular genetics , e.g. ‘-omics’, give an excellent precise tool to investigate the links between the disciplines of evolutionary biology, ecotoxicology, and invasions science and help elucidate the paradox.