The impact of rapid evolution on population dynamics in the wild: An experimental test using the green peach aphid (Myzus persicae)

Rapid evolution, occurring within a dozen generations or less, is now commonly observed in nature. Yet, most ecological studies assume that evolution is too slow to impact short-term ecological dynamics. We experimentally tested whether rapid evolution in the green peach aphid (Myzus persicae) impacts its concurrent population dynamics in replicated field populations. We manipulated the occurrence and rate of evolution by creating replicated aphid populations with different amounts of genetic variation in intrinsic growth rate. Within 31 days, or less, the frequency of aphid clones change significantly in the expected direction. This rapid evolution significantly increased the rate of aphid population growth as well as density compared to non-evolving controls. The magnitude of this effect however depends on the rate of evolution. Moreover, we present results from a greenhouse experiment that tests if aphid clonal selection is density-dependent.