Answer:
Both of the previous answers provide equally strong evidence that this is not a case of evolution.
Explanation:
A change in the phenotype of an organisms does not mean it is evolving. Humans can adapt to different climates or altitude. If one is getting to much sun skin may become darker but if you are barely getting sun your skin becomes lighter. Gene expression is influenced by the environment but this does not mean the species is evolving. On top of it the experiment shows phenotype changes in hot or cool temperature this implies that the phenotype is influenced by the temperature.