DOI: 10.5061/dryad.b8gtht7j6
title: Data from: The adaptive role of melanin plasticity in thermally variable environments

description: Understanding the evolution of adaptive plasticity is fundamental to our
 knowledge of how organisms interact with their environments and cope with
 environmental change. Plasticity in melanin pigmentation is common in
 response to variable environments, especially thermal environments. Yet,
 the adaptive significance of melanin plasticity in thermally variable
 environments is often assumed, but rarely explicitly tested. Furthermore,
 understanding the role of plasticity when a trait is responsive to
 multiple environmental stimuli and plays many functional roles remains
 poorly understood. We test the hypothesis that melanin plasticity is an
 adaptation for thermally variable environments using Hyles lineata, the
 white-lined sphinx moth, which shows plasticity in melanin pigmentation
 during the larval stage. Melanin pigmentation influences thermal traits in
 H. lineata, as melanic individuals had higher heating rates and reached
 higher body temperatures than non-melanic individuals. Importantly,
 melanin pigmentation has temperature specific fitness consequences. While
 melanic individuals had an advantage in cold temperatures, neither
 phenotype had a clear fitness advantage at warm temperatures. Thus, the
 costs associated with melanin production may be unrelated to thermal
 context. Our results highlight the importance of explicitly testing the
 adaptive role of plasticity and considering all the factors that influence
 costs and benefits of plastic phenotypes across environments.
description: # Data from: The adaptive role of melanin plasticity in thermally variable
 environments ## Description of data The data can be found in three files.
 The first file, “Exp1_ThermalTraits.csv” contains the data used for the
 first experiment. Below is a description of all variables. ID = individual
 larval label Devo_Day = The developmental day that the individual was
 tested (with Day 0 being the day that the egg was laid). All individuals
 are in the 5th (final) instar. Weight = Larval mass in grams Melanism =
 Melanin level (max and min refer to melanic and non-melanic Ambient =
 Ambient temperature under the light in degrees C Initial_temp = Body
 temperature of the larva at minute 0 in degrees C 4 = Body temperature of
 the larva at minute 4 in degrees C 24 = Body temperature of the larva at
 minute 24 in degrees C Rate_4 = Linear heating rate of larva over first 4
 minutes ((4-Initial Temp) / 4) measured as degrees C/ minute Rate_24 =
 Linear heating rate of larva over first 24 minutes ((24-Initial Temp) / 4)
 measured as degrees C/ minute Temp_Excess = Larval body temperature above
 ambient temperature (24-Ambient) measured as degrees C The second file,
 “Exp2_FitnessTraits.csv” contains the data used for the second experiment.
 Below is a description of all variables. ID = individual larval label
 Melanin = Melanin level (maximum and minimum refer to melanic and
 non-melanic Melanin_Percent = quantitative measure of melanin that was
 done for a subset of individuals (measured as percent area with melanic
 pixels, as explained in the text) Block = experimental block (due to space
 constraints experiment was conducted over 2 blocks) Treatment =
 temperature treatment (cold vs warm) Family = full sibling family
 designation Light position = whether larvae were placed under lights in
 the front, middle, or back of the chamber Initial_weight = Mass of larva
 at beginning of 5th instar (grams) Peak_weight = mass of larva at peak
 weight (grams) Development = number of days in 5th instar Growth_Rate_2to4
 = growth rate from days 2-4 of the 5th instar, measured as grams/day
 Growth_Percent_2to4 = growth percentage from days 2-4 of the 5th instar,
 measured as growth rate/ initial weight Growth_Rate_Total = growth rate
 from day 2 to final day of 5th instar, measured as grams/day
 Growth_Percent_Total = growth percentage from day 2 to final day of the
 5th instar, measured as growth rate/ initial weight Pupal_Weight = pupal
 mass (grams) Survival = binary measure of survival (for tallies see
 "Survival" file) Empty cells in this file indicate that an
 individual did not survive until that particular measurement. For example,
 if a larva died during the experiment and did not pupate there will not be
 a measurement for pupal weight. The third file, “Survival” is a simple
 summary of the survival among the four treatment groups. ## Code/ Software
 All statistical analyses and data figures were run in R. R file
 “Melanin_Adaptation.R” is included and can be run to replicate results
 once the data files are downloaded.