DOI: 10.5061/dryad.068b6
title: Data from: When field experiments yield unexpected results: lessons learned from measuring selection in White Sands lizards

description: Determining the adaptive significance of phenotypic traits is key for
 understanding evolution and diversification in natural populations.
 However, evolutionary biologists have an incomplete understanding of how
 specific traits affect fitness in most populations. The White Sands system
 provides an opportunity to study the adaptive significance of traits in an
 experimental context. Blanched color evolved recently in three species of
 lizards inhabiting the gypsum dunes of White Sands and is likely an
 adaptation to avoid predation. To determine whether there is a
 relationship between color and susceptibility to predation in White Sands
 lizards, we conducted enclosure experiments, quantifying survivorship of
 Holbrookia maculate exhibiting substrate-matched and substrate-mismatched
 phenotypes. Lizards in our study experienced strong predation. Color did
 not have a significant effect on survival, but we found several unexpected
 relationships including variation in predation over small spatial and
 temporal scales. In addition, we detected a marginally significant
 interaction between sex and color, suggesting selection for substrate
 matching may be stronger for males than females. We use our results as a
 case study to examine six major challenges frequently encountered in
 field-based studies of natural selection, and suggest that insight into
 the complexities of selection often results when experiments turn out
 differently than expected.
description: Holbrookia maculata
 processing dataThis file contains data
 for all Holbrookia maculata used in the study, including individual
 capture date/location, morphology data, trials each individual was
 included in, and whether the individual survived the
 trials.hmaculataprocessingdata.csvEnclosure recapture dataThis file contains recapture data for individual enclosure replicates. For each enclosure replicate, data are included on when the trial was run, which enclosure the trial was run in, and the number of substrate-matched and substrate-mismatched lizards that were recaptured.enclosuredata.csvThermal preference dataThis file contains data from thermal preference trials. Thermal preference trials were 90 minutes long, and we recorded data at 30 minute intervals throughout trials. For each lizard in the thermal preference trials, data are included on the lizard body temperature and distance of the lizard from the light source at each data collection point.thermalpreference.csvSpectrometer data 2011This file contains spectrometer data for painted and unpainted Holbrookia maculata collected in 2011. For each individual lizard that we measured with the spectrometer, data are included on percent transmittance at each wavelength when the lizard was unpainted, as well as after the lizard was painted.specdata2011.csvSpectrometer data 2012This file contains spectrometer data for painted and unpainted Holbrookia maculata collected in 2012. For each individual lizard that we measured with the spectrometer, data are included on percent transmittance at each wavelength when the lizard was unpainted, as well as after the lizard was painted.specdata2012.csv