Rapid evolution in range expansions

Range expansions play a key role in a wide variety of ecological phenomena including invasive species, species reintroductions, and the use of biological control agents. For many years, it was assumed that these expansions played out on short enough time scales that their dynamics were largely governed by ecological processes. However, researchers have recently begun to realize the dramatic role that rapid evolution can play in shaping range expansions. Through the accumulation of high dispersing individuals at the edge of expansion, increased dispersal can evolve, accelerating expansion speed through time. Further, the unique demography of populations at the expansion edge, characterized by low population sizes and repeated founding events, can result in highly variable evolutionary trajectories, thus increasing the overall variance of the expansion process. Using a combination of theoretical models and laboratory microcosms of the red flour beetle, and in collaboration with Ruth Hufbauer, Marianna Szúcs, and Brett Melbourne, we investigate the causes and consequences of rapid evolution in range expansions and the subsequent implications for conservation efforts.

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