CONCLUSIONS:
Overall, we found extensive variation in the influence of incubation
temperature on morphological and metabolic phenotypes across populations
of alligators. In contrast, the influence of maternal provisioning on
hatchling traits was mostly consistent across populations. While the
adaptive value of variable plastic responses to incubation temperature
was not explicitly tested, latitudinal patterns of some traits (i.e.,
incubation duration) may imply local adaptation. Nonetheless, variation
in the influence of incubation temperature on other traits suggests that
selection can act on those relationships, allowing populations to become
locally adapted and respond to changing environmental conditions.
However, the mechanisms responsible for differential responses to
incubation temperature are not known, including the extent to which they
are driven by genetic differences or other components of the
developmental environment. Determining the causes of these differences,
including the developmental mechanisms involved, would provide important
insight into how components of the developmental environment and
embryonic responses to them influence intraspecific variation and may
contribute to adaptive evolutionary change.