Answer:
No, these exceptions do not discredit natural selection.
Explanation:
Natural selection tends to favour those organisms which are better adapted to live in an environment. But it does not completely remove the other organisms from the world that are less adapted to live in an environment. Usually, the number of these organisms that are not favoured by natural selection is very less as compared to the number of organisms which are favoured by natural selection. As we see, the number of albino animals is far lesser as compared to their wild-type animals.