> They proposed that we genetically engineer a species of cat that changes color in the presence of radiation, which would be released into the wild to serve as

> They proposed that we genetically engineer a species of cat that changes color in the presence of radiation, which would be released into the wild to serve as living Geiger counters. This would seem to fail as a long-term plan due to genetic drift and natural selection. Presumably, there is no reproductive advantage to the cat in expressing fur color that indicates radiation. In the absence of selective pressure, the phenotype will gradually disappear as the radiation expressing cats mix with non-expressing cats. Since humans won't be actively maintaining the phenotype in the population against genetic drift (the opposite, in fact, since they avoid the cats) then over hundreds or thousands of years there will be no indicator cat phenotype.