Local adaptation to thermal gradients could cause populations in different parts of the range to respond differently.
In reality, adaptation to thermal stress, if it occurs on 100-year time scales, will likely not be linear.
Local adaptation to thermal gradients can cause populations in different parts of the geographic range to exhibit different responses to temperature variation [12] [18].
This suggests that either local adaptation or thermal acclimation in these species leads to a constancy in aerobic scope at the prevailing summer temperature.
Here we tested the hypothesis that differences in patterns of gene expression play a role in adaptation to thermal stress.
The only other recent study dealing with long-term adaptation to thermal challenge concerned C. gigas (3 months, 24 °C) [ 4].
However, few studies have identified the underlying molecular mechanisms that have led to conspecific adaptation to thermal conditions.
Latitude has been suggested as a potential gradient for local adaptation to thermal stress in mosquitoes [ 142].
The transcriptome resource from this study will aid future investigations of cold adaptation and thermal response of polar ectothermic species.
Still, given the low number of replicates, the geographic patterns described here should be treated as a suggestion, not a solid proof of local adaptation to thermal environment.
