A stabilizing eco-evolutionary feedback loop in the wild

Eco-evolutionary dynamics are predicted to involve feedback loops, where ecological changes driven by rapid evolution feed back to shape further evolution. However, direct experimental evidence for such loops in the wild is lacking. Here, we show that eco-evolutionary dynamics in a plant-feeding arthropod community involve a negative feedback loop. Specifically, adaptation in cryptic coloration in an abundant stick-insect species mediates bird predation, with local maladaptation increasing predation. In turn, the abundance of arthropods is reduced by predation. Here, we experimentally manipulate arthropod abundance to show that these community-level changes feedback to affect stick-insect evolution. Specifically, low arthropod abundance increases the strength of selection on crypsis, increasing local adaptation of stick insects in a negative feedback loop. Our results suggest that eco-evolutionary feedbacks are able to stabilize complex systems by preventing consistent directional chang..., We conducted an experiment to test whether variation in the arthropod community affects selection on Timema cristinae cryptic morphs. In this context, we manipulated the abundance of arthropods into low- and high-abundance treatments on individual host bushes of Adenostoma fasciculatum in nature. We then transplanted T. cristinae to the same bushes in a 50% ratio of striped and unstriped individuals. We allowed the experiment to run for three days in natural conditions after which we resampled each plant to determine the total number of T. cristinae individuals recaptured and changes in the proportion of each morph.
We used a replicated, randomized block design with two treatment levels: low-abundance (200 arthropod individuals) and high-abundance (600 arthropod individuals). Each of the two treatments was replicated five times within the study site. Experimental bushes were chosen to be approximately the same size and have a similar gross light exposure. The area below and surrounding ..., The data are in a plain text file.