Evolution of life history and dispersal traits during the range
expansion of a biological control agent
Abstract
Evolutionary theory predicts that the process of range expansion will
lead to differences between core and edge population in life history and
dispersal traits. Selection and genetic drift can influence reproductive
ability while spatial sorting by dispersal ability can increase
dispersal at the edge. However, the context of individuals (e.g.,
population density and mating status) also impacts dispersal behavior.
We evaluated theoretical predictions for evolution of reproductive life
history and dispersal traits using the range expansion of a biological
control agent, Diorhabda carinulata, or northern tamarisk beetle. We
found divergence of fecundity, age at first reproduction, and female
body size between core and edge populations. We also show that density
and mating status influence dispersal and that dispersal increases at
the edge of the range. We demonstrate that theory of evolution during
range expansions applies to the range expansion of a biocontrol agent,
especially when the ecological context is considered.