I think it's more useful to think of natural selection as acting (probabilistically) on populations of genomes, not individuals. The feedback is individual, but the "gradients" are at the population level. It's not a perfect analogy but e.g. there are formal correspondences like this one: https://www.nature.com/articles/s41467-021-26568-2
An interesting fact that I wasn't aware of until I read it recently is that our genes constrain the chance of mutations in critical areas of the body, which shifts the landscape.
Mutation resistance is itself the result of mutation (i.e. evolution), and isn't anything particularly special among humans. And it's not just critical areas; every cell in your body has enzymes that prevent mutation, both before and after a given replication.
Yeah, that's interesting, I guess it's also a simplification to think of an organism as a single genome. The reality is much more complicated! (lichens come to mind as examples of even more genetic diversity housed in a single organism, or even gut bacteria in humans maybe?)
