Genetic variation in dispersal ability may result in the spatial sorting of alleles during range expansion. Recent theory suggests that spatial sorting can favour the rapid evolution of life history traits at expanding fronts, and therefore modify the ecological dynamics of range expansion. Here we test this prediction by disrupting spatial sorting in replicated invasions of the bean beetle Callosobruchus maculatus across homogeneous experimental landscapes. We show that spatial sorting promotes rapid evolution of dispersal distance, which increases the speed and variability of replicated invasions: after 10 generations of range expansion, invasions subject to spatial sorting spread 8.9% farther and exhibit 41-fold more variable spread dynamics relative to invasions in which spatial sorting is suppressed. Correspondingly, descendants from spatially evolving invasions exhibit greater mean and variance in dispersal distance. Our results reveal an important role for rapid evolution during invasion, even in the absence of environmental filters, and argue for evolutionarily informed forecasts of invasive spread by exotic species or climate change migration by native species.
Invasion experiment data
Data collected from experimental laboratory invasions of the bean beetle Callosobruchus maculatus. Data show the post-dispersal densities of beetles in each patch of the one-dimensional invasion array. Columns (in order) are date, start time, end time, population ID, generation (1-10), treatment (0 = spatially sorted, 1 = shuffled), array_patch (the patch number in the dispersal array), array_shift (the cumulative number of patches that the invasion has been shifted towards 0 each generation to ensure that the invasion would fit in the spatial extent of the array), invasion_patch (array_patch + array_shift), N_females (number of females in each patch), N_males (number of males in each patch), N_unsexed (number of unsexed beetles in each patch), and notes.
invasion_experiment.csv
Common garden dispersal data
Data collected from a common garden experiment following experimental laboratory invasions of the bean beetle Callosobruchus maculatus. Data show the dispersal distance of beetles from each replicate population of the invasion experiment. Columns (in order) are date, start time, end time, population ID, common garden generation (1-2), treatment (0 = spatially sorted, 1 = shuffled), replicate (1-3; within-population replicate dispersal trials), sex (0 = female, 1 = male), distance (number of patches dispersed), and notes.
common_garden_dispersal.csv
Common garden fecundity data
Data collected from a common garden experiment following experimental laboratory invasions of the bean beetle Callosobruchus maculatus. Data show the lifetime reproductive success of females from each replicate population of the invasion experiment. Columns (in order) are date that offspring were counted, population ID, common garden generation (1-2), female ID (1-11 for each population), treatment (0 = spatially sorted, 1 = shuffled), and number of offspring produced by each female.
common_garden_fecundity.csv
Dispersal heritability data
Data collected from half-sib breeding design to investigate the additive genetic variance of dispersal distance in the bean beetle Callosobruchus maculatus. Data show the dispersal distance of beetles from each full-sib family. Columns (in order) are date, experiment start time, sire ID, dam ID, offspring ID, replicate (varies for each dam-sire combination depending on the number of offspring the pair produced), sex (0 = female, 1 = male), and distance (number of patches dispersed).
dispersal_heritability.csv