Survival of the fittest ---- Group

Human species has dominated the planet since they came into existance. We are a species like none other. Looking at the human society purely from a scientific prospective, we find a very high survival rate. We dont have any natural predators and the danger to our life is mostly from mocirobes and ourselves.
This I believe goes against Survival of the fittest. Darvin said the ones most fit to survive the current conditions will dominate. Human species seems to disagree. Everyone of the species has the oppertunity to create offsprings. They need not be the fittest, neither physically or mentally. Our species progressed because of our intelligence and adaptiveness.
We were able to use our skills and mental powers to first adapt to the sorrounding and then later change the sorroundings to fit our needs. Now we have covered the entire planet. The question is who all survived. And the answer is everybody. The requirement for survival could have been ability to think, ability to adapt to the environment, the ability to fight some desiese. But as a group we made certain that none of it mattered. Some of us might have had resistance to some desiese, the ones with brains made certain we could reproduce it so that everyone survived and the ones physically fit kept us entertained.
So what about evolution. Are we still evolving? Maybe we are. But it is different from the kind of evolution that we might have once had, atleast in the rate if not the kind itself.
During our initial evolution, our aim always was to survive, against nature and predators. Now neither is a problem. We have developed enough to either negate the effects of environment or to remove it completly. As all can have offsprings so the intelligence quotient has more or less stagnated.
Physically are we changing? Other than surgical removal of certain parts of our body which we might no longer need, we dont really do any changes to the physic itself internally. Externally, we have peoples with all sizes and forms. Thin, fat, well toned, malnurished. Even different species of the same species and mixed breeds. And all of them surivive and have off springs.
So as a group, the Human species has made certain everyone survives and maybe even put a break on evolution.