Good question. I feel natural selection works in more ways than just "survival of the fittest" sense of the term.
For example, for millions of years our bodies have become adept at precisely the amount of gravity Earth pulls on our bodies. Whether or not that has affected the species ability to reproduce, or if it's consequential to our ability to live comfortably in space, is another question, but I feel there are more ways evolution has affected our genes (to be more perfectly adapted to Earth's environment) than we may realize.
For example, for millions of years our bodies have become adept at precisely the amount of gravity Earth pulls on our bodies. Whether or not that has affected the species ability to reproduce, or if it's consequential to our ability to live comfortably in space, is another question, but I feel there are more ways evolution has affected our genes (to be more perfectly adapted to Earth's environment) than we may realize.