No, everyone who breeds passes on their genes. The “better adapted” (to what?) could be killed in a fire before they reach puberty, and people with hereditary diseases have kids.

It only has to be good enough to survive to puberty and birth, puberty and birth. Whatever it is you’re thinking of as some kind of superior gene would only affect humanity if it were passed on by millions of people who had it, and it proved to be such a boon it meant they could have kids while others can’t.

There is currently no natural pressure on humans to not have kids. There is nothing, technically speaking, preventing me from having a baby with a supermodel, an athlete, a wheelchair user…