DOI: 10.5061/dryad.280gb5mvk
title: The influence of incubation temperature on offspring traits varies across northern and southern populations of the American alligator (Alligator mississippiensis)

description: Maternal provisioning and the developmental environment are fundamental
 determinants of offspring traits, particularly in oviparous species.
 However, the extent to which embryonic responses to these factors differ
 across populations to drive phenotypic variation is not well understood.
 Here, we examine the contributions of maternal provisioning and incubation
 temperature to variation in hatchling morphological and metabolic traits
 across four populations of the American alligator (Alligator
 mississippiensis), encompassing a large portion of the species’
 latitudinal range. Our results show that whereas the influence of egg mass
 is generally consistent across populations, responses to incubation
 temperature show extensive population-level variation in several
 fitness-related traits, including mass, head length, head width, and
 residual yolk mass. Additionally, the influence of incubation temperature
 on developmental rate is greater in northern populations, while the
 allocation of maternal resources towards fat body mass is greater in
 southern populations. Overall, our results suggest that responses to
 incubation temperature, relative to maternal provisioning, are a larger
 source of interpopulation phenotypic variation and may contribute to the
 local adaptation of populations.
description: Common garden incubation experiment. Alligator eggs were
 collected and incubated in a cross-foster design across two temperature
 treatments (29.5°C and 33.5°C). After hatching, neonates were raised in
 common garden conditions for ten days.
description: # The influence of incubation temperature on offspring traits varies
 across northern and southern populations of the American alligator
 (Alligator mississippiensis) Alligator eggs were collected, weighed and
 measured from four populations and incubated under one of two temperature
 treatments: a constant male-promoting temperature (33.5C) and a constant
 female-promoting temperature (29.5C). At hatch, neonates were measured and
 raised for ten days in common garden conditions. Hatchlings were then
 euthanized to obtain additional tissue measurements.  ## Description of
 the data and file structure **Smaga_et_al_2023_ecol_evol_data** - A .csv
 file containing phenotypic measurements. Blank values indicate missing
 data (n/a) from the experiment. Column names are as follows, with units in
 parentheses: * edd_ID - individual egg ID * site - population egg was
 collected from * clutch - clutch number egg originated from by site
 abbreviation * temp - incubation temperature treatment (degrees celsius) *
 egg_mass - initial egg mass (g) * st15_to_pip - incubation duration from
 st15 of development until pipping (days) * mass - mass at hatch (g) * svl
 - snout vent length (cm) * tg - tail girth at the cloaca (cm) * hl - head
 length (mm) * hw - head width (mm) * bmi - body mass index, calculated as
 mass/2*svl (g/cm^2) * delta_mass - change in mass over 10 days (g) *
 delta_svl - change in svl over 10 days (cm) * delta_tg - change in tg over
 10 days (cm) * delta_bmi - change in bmi over 10 days (g/cm^2) * res_yolk
 - mass of residaul yolk (g) at 10 days post hatch * fat_body - mass of fat
 body (g) at 10 days post hatch **Smaga_et_al_2023_ecol_evol_hatch_counts**
 - A csv file containing survival and hatch rates by temperature, clutch
 and site. Column names are as follows, with units in parentheses: * site -
 population egg was collected from * clutch - clutch number egg originated
 from by site abbreviation * id - individual egg identifier * temp -
 temperature treatment egg was incubated at (degrees celsius) * hatch -
 whether an egg hatched (1 = yes, 0 = no) * ten_day - whether an individual
 survived the 10-day post-hatch period (1 = yes, 0 = no)
 **Smaga_et_al_2024_ecol_evo_stats.R** (Zenodo-Software) - Simplified R
 script for the models utilized in the analyses, using R (version 4.4.0) in
 RStudio.