Gene flow at a range edge
A field experiment testing whether gene flow rescues or swamps marginal populations
At the edge of a species’ range, gene flow from the range core can either fuel adaptation by importing useful variation or swamp it by overwhelming local selection. Using experimental crosses between core and edge populations of Clarkia xantiana, transplanted back into the range margin, we’re directly measuring the fitness consequences of admixture across the species’ range — and asking whether gene flow helps or hurts populations facing novel conditions.
With Jacob Landis (Cornell).