An average person of your race is probability your cousin if you look back 15 generations. If it were not for in-breeding, the number of grandparents you would have 32 generations back would be 4 billion. Environment and heredity combine to shape a person. Identical twins separated at birth show heredity can play the far larger role. When an environment is extreme it is much more important, but usually its effect is small.
Evolution occurs in two ways, mutation and natural selection.
Although mutations are necessary for the changes which natural selection selects from, mutations are not what cause the most noticeable changes. Even with the extra radiation and tradagenic toxins, selective evolution is all that has effected us much in the last 6000 years or so. Like some bird s plumage, beauty seems extravagant for a miser like evolution. Part of its value, like money, is that it is agreed to have a value. Because everyone wants beauty, the best get it.