PS 7-94 - Experimentally simulating the evolution-to-ecology connection: divergent predator morphologies alter natural food webs

Abstract: The idea that changing environmental conditions drive adaptive evolution is a pillar of evolutionary ecology. But the opposite—that adaptive evolution alters ecological processes—has received far less attention yet is critical for eco-evolutionary dynamics. We assessed the ecological impact of divergent values in a key adaptive trait using 16 populations of the brown anole lizard (Anolis sagrei). Mirroring natural variation, we established islands with short or long-limbed lizards at both low and high densities. We monitored changes in lower trophic levels, finding that web-spider densities decreased on short-limbed, high-density islands, and that plants grew more on islands with short-limbed lizards via an indirect positive effect likely through an herbivore-mediated trophic cascade. Our experiment provides strong support for evolution-to-ecology connections in nature, closing an otherwise well-characterized eco-evolutionary feedback loop.