Perhaps Chuck has not understood that Kettlewell did his experiments in 1955 and that the experiments were the first ever on this topic. So of course his results were used for teaching purposes, until Grant’s observations on Geospiza fortis were the better example. Since when is it required that the first experiment in a field is for all eternity? And in fact, the result stands: the peppered moth morphs are undermeasurable visual selection by bird predators.