Meeting Abstract
Dispersal ability varies significantly among individuals, and much of this variation can be described by a suite of co-varying morphological, physiological, behavioural, and life-history traits (dispersal syndromes). While dispersal syndromes have been well-studied within and among populations, our understanding of the evolutionary trajectories of traits associated with dispersal under selection is limited. We used the red flour beetle (Tribolium castaneum) in a laboratory dispersal system to assess how spatial selection processes, for and against dispersal, affected dispersal-related traits. We measured body size, relative leg length, routine metabolic rate, and aspects of movement behaviour over seven generations of artificial selection. Here we will discuss our findings that body size rapidly diverged over seven generations, such that dispersers became smaller and non-dispersers became larger, and that dispersers had a lower metabolic rate. Small individuals were more energetically and biomechanically efficient at climbing, and were therefore the ones that dispersed more. The variance in dispersal rate and movement was maintained even under intensive selection for opposing dispersal behaviours. This indicates that individuals may maximise their fitness by producing offspring that exhibit a variety of dispersal behaviours; a hypothesis that is further supported by the lack of a trade-off between dispersal behaviour and reproductive success.
