DOI: 10.5061/dryad.bk3j9kdj1
title: Data from: A stabilizing eco-evolutionary feedback loop in the wild

description: 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
 change and therefore increasing resilience.
description: We conducted an experiment to test
 whether variation in the
 arthropod community affects selection on <em>Timema cristinae</em> cryptic morphs. In this context, we manipulated the abundance
 of arthropods into low- and high-abundance treatments on individual host
 bushes of <em>Adenostoma fasciculatum</em>
 in nature. We then
 transplanted <em>T. cristinae</em> 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
 <em>T.
 cristinae</em> 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 experimental bush was cleared
 out of other vegetation in order to minimize dispersal of arthropods to or
 from adjacent plants.
 Thus, we created
 ‘experimental
 islands’ such that any
 change in density or morph
 frequency of
 <em>T.
 cristinae</em> was
 assumed to be from mortality. Our experimental design implements a
 complete randomized block
 design which allowed us to account for possible sources of error intrinsic
 to field experimentation (e.g., differences in light exposure,
 micro-climate etc). Such variations might occur but should be random with
 respect to treatment such that they cannot readily explain treatment
 effects. On March 15,
 2022, we transplanted 40 <em>T. cristinae</em> individuals to each treatment in each block.
 Because we were interested in whether arthropod abundance has an effect on
 color-pattern morph frequency in <em>T. cristinae</em>, we used a 50% ratio of striped and unstriped
 individuals, thus maximizing the potential for evolution and selection. In
 parallel, the arthropods corresponding to each treatment were transplanted
 to the experimental bushes. To ensure that the arthropods were transferred
 to the bushes, we placed the open plastic containers in the middle of the
 plant and let the arthropods move from the plastic container to the plant
 undisturbed. We let the
 experiment run for three days after which we recaptured the surviving
 individuals using sweep nets and examining each experimental bush. Each
 branch of the experimental bush was systematically sampled for
 <em>T. cristinae
 </em>individuals.
 Sampling ceased when no new individuals were collected after at least
 several minutes of extensive searching. In addition, the total number of <em>T. cristinae</em>
 recaptured on each
 experimental bush and the color-pattern of each individual were
 recorded.
description: The data are in a plain text file.