Urban Environments As A Framework To Study Parallel Evolution

Abstract Urban environments represent globally replicated, large-scale disturbances to the landscape, providing an ideal opportunity to study parallel evolution in natural populations on a large scale. In recent years, there has been a rapid increase in the number of studies investigating evolutionary responses of a diverse range of taxa across multiple cities. Although parallel evolutionary responses across independent urban environments will depend on the extent to which urban environments converge on similar biotic and abiotic environments, the extent to which cities are environmentally similar has not yet fully been integrated into studies of urban evolution. This chapter begins by asking: Do species display parallel evolutionary responses across independent urban environments? It then briefly reviews a subset of the environmental factors that have driven parallel responses to cities (heat islands, pollution, and habitat fragmentation) and discusses some of the potential causes of non-parallelism. Finally, it ends with practical considerations for the design of future studies aiming to examine parallel evolutionary responses to urbanization. Understanding the shared and unique features of urban environments and identifying parallel species responses to rapid and ongoing urban development will provide important insight into the ubiquity of parallel evolution in nature.