Best of both worlds: Acclimation to fluctuating environments confers advantages and minimizes costs of constant environments
Data files
Jan 30, 2024 version files 31.96 KB
-
best_of_both_worlds_data_FE_20072023.csv
-
meta_best_of_both_assay_times.csv
-
README.md
-
README.txt
-
sprint_assay_order_check.csv
Abstract
- Thermal acclimation is often considered critical in organismal responses to novel thermal conditions. Our understanding of the physiological implications of acclimation is largely derived from lab studies with simplified thermal regimes that fail to account for any variation that animals would experience naturally (i.e. diel variation). As such, constant temperature acclimation experiments may produce a flawed understanding of acclimation in the wild.
- To fill this gap, we acclimated lizards (Amphibolurus muricatus) under three thermal regimes (Hot Constant, Cold Constant and Alternating) and compared their physiological responses (Metabolic Rate, Sprint Speed, Thermal Preferences and Thermal Limits).
- We found that animals maintained constantly at hot temperatures (preferred temperature, 35°C) gained sprint performance increases, not seen in those maintained constantly at cold temperatures (20°C), yet suffered costs to growth (in younger animals) and maintenance (mass loss in older animals). Animals maintained at alternating temperatures (12 hr 20°C; 12 hr 35°C) had performance benefits matching animals in the hot treatment, without experiencing reductions in juvenile growth and adult mass.
- Animals acclimated under hot temperatures showed a significant lower preferred and voluntary maximum temperatures compared to animals acclimated under a cold temperature regime.
- We found no impact of acclimation treatment on behavioural thermal limits or Standard Metabolic Rate.
Overall, we show that alternating between access to preferred temperatures and having periods of energetic rest confer the greatest benefits for our animals. These results highlight the importance of natural body temperature variation for enhancing overall ectotherm performance and physiology, and the costs of novel thermal environments that fail to provide this variation.
README: Best of both worlds: Acclimation to fluctuating environments confers advantages and minimizes costs of constant environments
https://doi.org/10.5061/dryad.tdz08kq31
Dataset contains information on lizards that underwent three acclimation treatments (Hot, cold, fluctuating) and presents phenotyping data for metabolic rate and sprint performance across five temperatures as well as thermal preferences and behavioural thermal limits. Animals were found to shift phenotypes in response to treatment with animals under fluctuating regimes having the benefits of accessing hotter temperatures with lower putative costs.
The attached R files contain code to perform the analysis presented in the manuscript.
Description of the data and file structure
Methodological Information
==========================
* Methods of data collection/generation: see manuscript for details
Description of the data and file structure
==========================
File Summary
* 4 Files in total, 3 .csv files and 1 RMD.
- best_of_both_worlds_data_FE_20072023.csv
- meta_best_of_both_assay_times.csv
- sprint_assay_order_check.csv
- Best_of_both_worlds_revised_final.Rmd
File/Folder Details
===================
Details for: best_of_both_worlds_data_FE_20072023.csv
---------------------------------------
* Description: Primary dataset used for analysis including all physiological phenotyping data and experimental information.
* Format(s): .csv
* Dimensions: 40 rows x 69 columns
* Variables:
- ref : a reference number for each line
- animal.id: animal identification number
- batch: animal experimental block number (1 - 12)
- treatment: Animal treatment group; 35.constat = Hot Constant, 20.constat = Cold Constant, 35.20.flip = Alternating. See manuscript for more details.
- age.class: Age of animals at time of experiment. See Manuscript for details of age class breakdown.
- sex: genetic sex; F = female; M = male
- start.mass.g.: Mass prior to acclimation treatment in grams
- metabolism.mass.g.: Mass of animals when undergoing metabollic assays in grams.
- home.cage: Housing outside of the experimental treatments that animal where animal was housed.
- acclimation.start: Start date of acclimation treatment
- acclimation.finish: finish date of acclimation treatment
- metabolism.date: Date of metabolism assay
- sprint.1.date: Date of first sprint assay
- sprint.2.date: Date of second sprint assay
- thermal.preferance.date: Date of thermal preference assay
- metabolism_chamber_size: Size of metabolic chambers (ml) used for different sized lizards
- metabolism.15: Rate of C02 produced (in ml per minute) by animals at 15 degrees Celsius
- metabolism.22: Rate of C02 produced (in ml per minute) by animals at 22 degrees Celsius
- metabolism.29: Rate of C02 produced (in ml per minute) by animals at 29 degrees Celsius
- metabolism.34: Rate of C02 produced (in ml per minute) by animals at 34 degrees Celsius
- metabolism.39: Rate of C02 produced (in ml per minute) by animals at 39 degrees Celsius
- sprint.max.15: Maximum sprint speed of lizards (m/s) at 15 degrees Celsius
- sprint.max.22: Maximum sprint speed of lizards (m/s) at 22 degrees Celsius
- sprint.max.29: Maximum sprint speed of lizards (m/s) at 29 degrees Celsius
- sprint.max.34: Maximum sprint speed of lizards (m/s) at 34 degrees Celsius
- sprint.max.39: Maximum sprint speed of lizards (m/s) at 39 degrees Celsius
- Tpref: Preferred temperature range of lizard calculated as the median of all values recorded whilst in the thermal gradient
- tpref_mean_of_qrt_range: Preferred temperature range of lizard calculated as the median of all values within the 1st and 3rd quartile of values recorded whilst in the thermal gradient.
- TSet: The select temperature range calculated as the range between the 1st and 3rd quartile of values recorded whilst in the thermal gradient.
- VTmin: The single lowest value in degrees Celsius recorded in the thermal gradient for each animal.
- X25Quart: The 1st quartile of values for each animal from temperature records in the thermal gradient.
- X75Quart: The 3rd quartile of values for each animal from temperature records in the thermal gradient.
- VTmax: The single highest value in degrees Celsius recorded in the thermal gradient for each animal.
- Tpant: The value in degrees Celsius at which an animal began to pant.
- Escape.Temp: The value in degrees Celsius at which an animal began to to display escape behviour from heat source (See manuscript)
- tpant.valid: If the assay met criteria for inclusion y = Yes, n = no. See manuscript for inclusion details.
- thermal.pref.valid. : If the assay met criteria for inclusion y = Yes, n = no. See manuscript for inclusion details.
- comment.metabolism: Comments on the metabolism assay
- comment.sprint: Comments on the sprint assay
comment.thermal: Comments on the thermal assay
Note: NA values represent an absence of data due to equipment failure, failing to meet inclusion criteria (e.g. animals would not run for sprint assay) or unplanned researcher absence. Refer to manuscript for further details.
Details for: meta_best_of_both_assay_times.csv
---------------------------------------
* Description:Dataset used for supplementary analysis to validate no signficant effects of circadian rhythm on measured metabolic rates. See supplementary materials of manuscript for detailed methods.
* Format(s): .csv
* Dimensions: 61 rows x 7 columns
* Variables:
- batch: animal experimental block number (1 - 12)
- date: Date of metabolism assay
- temperature: Temperature of assay in degrees celsius
- measurement_time_24hr: Time of day that measurement occured in 24hr time
- measurement_time_12hr: Time of day that measurement occured in 12hr time with AM and PM.
- order : THe order of assay temperatures, with 1 = first assay and 5 = final assay.
- after_sunset: If measurements occured after sunset (y = yes, n = no). See supplemntary material details about determining sunset times.
Details for: sprint_assay_order_check.csv
---------------------------------------
* Description:Dataset used for supplementary analysis to validate no signficant effects of exhaustion on lizard sprinting performance. See supplementary matrials of manuscript for detailed methods.
* Format(s): .csv
* Dimensions: 59 rows x 5 columns
* Variables:
- batch: animal experimental block number (1 - 12)
- temperature: Temperature of assay in degrees celsius
- assay_day: Wheather tempeartures were assayed on the first day =1, or the second day = 2.
- day_order: The order of temperatures assayed on each assay day. 1 = first temperature assayed that day, 2 = Second temperature assayed that day, 3 = Third temperature assayed that day.
- total_order: The total order across both days of temperature assays.
Sharing/Access information
All data was derived from experimental procedures and not present on other public repositories.
Code/Software
Details for: Best_of_both_worlds_revised_final.Rmd
---------------------------------------
* Description: Code used to perform the analysis presented in the manuscript including the generation of thermal performance curves (TPCs) and subsequent analysis.
* Format(s): .RMD
* Version: Run in R v. 4.0.2
* Required Packages: See RMD file for all packages not included in base R that are required to repeat the analysis.
Methods
Data was collected using standard methods of closed system respirometry, sprint performance, thermal preferences and limits.
Processed in Kinovea (sprint), Warthog (SMR), Excel (Thermal Preferences). Data wrangling and analysis in R.