Constitutive up-regulation of Turandot genes rather than changes in acclimation ability is associated with the evolutionary adaptation to temperature fluctuations in Drosophila simulans.

•Evolutionary adaptation to fluctuating temperatures was studied in D. simulans.•We found no evolved difference in the acclimation response to increased temperature.•No circadian controlled change in heat resistance was observed for the evolved lines.•Increased expression of Turandot genes suggests a role for temperature fluctuations.