PT - JOURNAL ARTICLE AU - K. Van Petegem AU - Felix Moerman AU - Maxime Dahirel AU - Emanuel A. Fronhofer AU - Martijn L. Vandegehuchte AU - Thomas Van Leeuwen AU - Nicky Wybouw AU - Robby Stoks AU - Dries Bonte TI - Kin competition overrules spatial selection as driver of range expansions AID - 10.1101/150011 DP - 2017 Jan 01 TA - bioRxiv PG - 150011 4099 - http://biorxiv.org/content/early/2017/06/19/150011.short 4100 - http://biorxiv.org/content/early/2017/06/19/150011.full AB - With ongoing global change, life is continuously forced to move to novel areas, thereby imposing rapid changes in biotic communities and ecosystem functioning. As dispersal is central to range dynamics, factors promoting fast and distant dispersal are key to understanding and predicting range expansions. As the range expands, genetic variation is strongly depleted and genetic homogenisation increases. Such conditions should reduce evolutionary potential, but also impose severe kin competition. Although kin competition drives dispersal, we lack insights into its contribution to range expansions, relative to other causal processes. To separate evolutionary dynamics from kin competition, we combined simulation modelling and experimental range expansion using the spider mite Tetranychus urticae. Both modelling and experimental evolution demonstrated that plastic responses to kin structure increased range expansion speed by about 20%, while the effects of evolution and spatial sorting were marginal. This insight resolves an important paradox between the loss of genetic variation and earlier observed evolutionary dynamics facilitating range expansions. Kin competition may thus provide a social rescue mechanism in populations that are forced to keep up with fast climate change.