Meeting Abstract
A large degree of individual variation in learning ability has been shown to exist in natural populations of many animals; including birds, mammals and insects. Learning ability is heritable and can be rapidly increased through artificial selection and experimental evolution in natural and laboratory environments. This suggests that the observed individual variability in this trait is maintained through a balancing of the costs and benefits of enhanced cognition. Enhanced learning ability could theoretically benefit an animal by facilitating better retention of salient information, by increasing the chances of successful innovation or by allowing for increased survival under conditions of high predation. The costs of increased learning can be developmental, operational or syndromic (e.g. learning-adept individuals could be more prone to sample dangerous environments, increasing sensitivity to predation). As part of a separate experiment investigating the effect of environmental change on the evolution of learning, we evolved replicate populations of Drosophila melanogaster that display enhanced learning ability across a suite of contexts when compared to lab-reared controls. We conducted two experiments to test responses to predation in these populations and their controls. In the first experiment, we filmed individuals from each population type while in the presence of a mantis predator (Tenodera sinensis) and measured fly casualties and avoidance behaviors over time. In the second experiment, we labeled individuals from each population and measured their survival after 3 hours in the presence of the predator. We present data from these experiments to show the effect of learning ability on survival under predation. Our experiments add to our empirical understanding of the costs and benefits of learning ability and of the maintenance of individual variation in this trait in natural populations.
