DOI: 10.5061/dryad.3nk78
title: Data from: Lizards on newly created islands independently and rapidly adapt in morphology and diet

description: Rapid adaptive changes can result from the drastic alterations humans
 impose on ecosystems. For example, flooding large areas for hydroelectric
 dams converts mountaintops into islands and leaves surviving populations
 in a new environment. We report differences in morphology and diet of the
 termite-eating gecko Gymnodactylus amarali between five such newly created
 islands and five nearby mainland sites located in the Brazilian Cerrado, a
 biodiversity hotspot. Mean prey size and dietary prey-size breadth were
 larger on islands than mainlands, expected because four larger lizard
 species that also consume termites, but presumably prefer larger prey,
 went extinct on the islands. In addition, island populations had larger
 heads relative to their body length than mainland populations; larger
 heads are more suited to the larger prey taken, and disproportionately
 larger heads allow that functional advantage without an increase in
 energetic requirements resulting from larger body size. Parallel
 morphological evolution is strongly suggested, because there are
 indications that, before flooding, relative head size did not differ
 between future island and future mainland sites. Females and males showed
 the same trend of relatively larger heads on islands, so the difference
 between island and mainland sites is unlikely to be due to greater
 male–male competition for mates on islands. We thus discovered a very fast
 (at most 15 y) case of independent parallel adaptive change in response to
 catastrophic human disturbance.
description: Data used for analysis
 of niche breadthData are from
 Gymnodactylus amarali individuals collected from field sites near the
 Serra da Mesa Reservoir in central Brazil. The following column headings
 are used. area: Each field site was either an island created by the
 filling of the reservoir or part of the adjacent mainland site: a unique
 identifier for each field site lizard: a unique identifier for each lizard
 captured as part of the study termite.length_mm: the length of individual
 termites (in millimeters) found in the stomach of lizards used in the
 studyNicheBreadth.csvData used for the analysis of termite lengthData are from Gymnodactylus amarali individuals collected from field sites near the Serra da Mesa Reservoir in central Brazil. The following column headings are used. area: Each field site was either an island created by the filling of the reservoir or part of the adjacent mainland site: a unique identifier for each field site lizard: a unique identifier for each lizard captured as part of the study sex: male, female, or unknown snout.vent.length_mm: the snout-vent length of the individual lizard head.length_mm: the length of the head of the individual lizard mean.termite.length_mm: the mean length of termites found in the stomach of each individual lizardTermiteLength.csvData used for analysis of head lengthData are from Gymnodactylus amarali individuals collected from field sites near the Serra da Mesa Reservoir in central Brazil. The following column headings are used. area: Each field site was either an island created by the filling of the reservoir or part of the adjacent mainland site: a unique identifier for each field site lizard: a unique identifier for each lizard captured as part of the study sex: male, female, or unknown snout.vent.length_mm: the snout-vent length of the individual lizard head.length_mm: the length of the head of the individual lizardHeadLength.csv