This sounds terribly harsh but I ask this on a purely scientific basis. I am by no means a doctor so take this question for what it is.

I know medical science has advanced leaps and bounds in the past few centuries, as has the life expectancy of the world. These advances has allowed people that normally would not have made it to survive and live their lives. These people pass on these possible defects to their offspring thereby perpetuating the problems. We evolved to where we are by having a "survival of the fittest" where the weak and sickly die out not to have their genes passed on to future generations. By keeping alive all the unhealthy persons and curing diseases with medicine are we going to reach a time where our medical science will not be able to make up for our incompetence as a species?

The same reason doctors and farmers don't like to use the strongest antibiotics and pesticides, because eventually the bacteria and insects evolve and overcome them. Forcing us to make stronger and stronger antibiotics and pesticides.


Without the "defect" people dying out there is no evolution and would we actually devolve to a point where we can no longer sustain ourselves to a point were we could easily be wiped out by a massive virus outbreak or a similar circumstance?