Biology is very complex and contrary to public believe generally wasteful and not efficient and also not beautifully designed and in harmony but messy, and so i

Biology is very complex and contrary to public believe generally wasteful and not efficient and also not beautifully designed and in harmony but messy, and so is genetics. The chance that a single random base pair mutation (not a gene) actually gets activated/expressed and forms a functioning protein that is even advantageous for survival and gets passed down to descendants is tiny. Cancer or a rare genetic condition is much more likely.