The Influence of Incubation Temperature on Offspring Traits Varies Across Northern and Southern Populations of the American Alligator (Alligator mississippiensis)

Authors

Christopher R Smaga
Samantha L Bock
Josiah M Johnson
Thomas Rainwater
Randeep Singh
Vincent Deem
Andrew Letter
Arnold Brunell
Benjamin B Parrott

Publication Date

2-1-2024

Journal

Ecology and Evolution

Abstract

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 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 population-level variation in several traits, including mass, head length, head width, and residual yolk mass. Additionally, the influence of incubation temperature on developmental rate is greater at northern populations, while the allocation of maternal resources toward fat body mass is greater at 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.

Keywords

developmental plasticity, life history, maternal provisioning, temperature‐dependent sex determination

Comments

Data Availability Statement

PMID: 38371857