Rapid Evolutionary Responses to Radical Habitat Change
How can we assess whether populations have the potential to evolve in response to catastrophic environmental change, such as biological invasions, oil spills, or climate change? To what extent are populations constrained from undergoing an evolutionary response? And would independently derived populations show evidence of parallel evolution? This talk summarizes key results from several studies, including laboratory selection experiments, population genomics, gene expression analyses, quantitative genetics, and comparative physiological studies that document rapid evolutionary responses to catastrophic environmental change. For example, invasive populations are particularly striking in their capacity to extend their ranges into novel habitats. Analyzing populations that can invade, relative to those that cannot, point to the nature of the native range in shaping the evolutionary potential to undergo habitat shifts. This talk will focus on some key adaptations in response to catastrophic change, across hierarchical levels, from population genomic signatures of selection at ion transporter genes to the molecular evolution of catalytic regions in ion transporters that enable functional evolution during habitat change. We have found the same genomic regions under selection across independent habitat invasions, as well as in selection experiments in the laboratory. These results are important for understanding how populations will respond to future environmental changes.