Negative interactions between species can generate divergent selection that causes character displacement. However, other processes cause similar divergence. We use spatial and temporal replication of island populations of Anolis lizards to assess the importance of negative interactions in driving trait shifts. Previous work showed that the establishment of Anolis sagrei drove resident Anolis carolinensis to perch higher and evolve larger toepads. To further test the interaction’s causality and predictability, we resurveyed a subset of islands nine years later. Anolis sagrei had established on one island between surveys. We found that A. carolinensis on this island now perch higher and have larger toepads. However, toepad morphology change on this island was not distinct from shifts on six other islands whose Anolis community composition had not changed. Thus, the presence of A. sagrei only partly explains A. carolinensis trait variation across space and time. We also find that A. carolinensis on islands with previously established A. sagrei now perch higher than a decade ago, and that current A. carolinensis perch height is correlated with A. sagrei density. Our results suggest that character displacement likely interacts with other evolutionary processes in this system, and that temporal data are key to detecting such interactions.

Please see the paper for details.

perch.height.southTwin.csv

This is the 2019 perch height data set for South Twin and the other six islands. dstrb-yes means that the perch heigh of a lizard was likely changed by our presence. Tree height is the total height of the tree that the perch was on. as.int.sex notes whether one or more A. sagrei was "nearby" the perch and what their sex was/were; see main text for definition of nearby.

101207_Mosquito Lagoon_Ecology Morphology_Master.csv

This is the dataset collected in 2010 that is associated with Stuart et al (2014; Science). See the main text for the citation. as.int is, again, whether an A. sagrei was nearby.

2019_toepad.csv & 2019_svl_mass.id.csv

File 1 is the toepad data set for lizards captured in 2019 on South Twin and the six control islands. Each individual gets 2 rows, one for Left side and one for Right. File 2 is the mass, snout-vent length, and confirmed sex of every captured lizard in 2019.

toes_male_female.csv

This contains the lamella count and toepad area of lizards captured in 2010. It contains left side (".l"), right side (".r"), and average (".av"). Morph.good.av values of 1 mean that the toepads were undamaged and images were collected well for both sides. SVL is also in this data set.

catch.effort.southTwin.csv

This is the result of the catch-per-unit effort survey for A sagrei density. One person walked islands for 1 hour in th emorning, noting the sex and perch height of Anolis sagrei.

Dryad_Kamath_etal.R

This is R script that will reproduce all tables, figures, and results from the paper. It calls on the data sets listed above.