This is a really interesting thing to think about and something that science nerds like me like to think about. What about genetic disorders like autism and down syndrome? Have these disorders become more frequent because we nurture and make life for these people normal enough that they are actually able to reproduce and pass on their genes in some situations. If they never reproduce than they do not really figure into evolution because evolution only takes place on heretable traits that are passed on from generation to generation. If the traits are not passed on through reproduction (in the case of organisms that use sexual reproduction like humans) than it wouldn't have a fact in evolution. Crazy stuff to think about. A member of any of the other species in our genus Homo that had a genetic disorder definitely would not have had the same chances of reproducing as members of our species.

Yeah, I am definitely not suggesting that we limit who can reproduce. And I am happy that you are not suggesting that I suggested it ha ha. Going down the road of controlling stuff like that is a slippery slope to all kinds of nastiness. Thinking about the processes and how we got here is a very interesting thing though.

Selective breeding to many degrees has served mankind well over the millenium.  Without it we never would have what we now know as the domesticated dog breeds we enjoy today.  In primiative times those dogs who displayed undesireble traits were culled to ensure we engineered the domestic dog to our needs.  Same goes for other domestic animals and livestock too.  I do worry the practice could one day be carried over to humans on a widespread field.  The movie Gattica really scared me to think what man is capable of doing to other humans. But then again when you look at countries like developed western European countries, Japan, China, their birth rate is unacceptably low.  Europeans will be nearly extinct in the next 100 years if they don't start breeding again.  The birth rate here has dropped pretty significant, but at least Americans are still having kids, even if it is one kid.  Sadly many Americans have replaced having real children with having lap dogs instead and if that continues to become the norm we are going to be in real trouble.

Well, from what I see in nature in general, species have a way of trying to protect the weak and injured.  Sure, the predators target these animals, but with the young ones and others that cannot defend themselves, the stronger and bigger animals will help out, especially in a pack mentality.  Look at herds like elephants, water buffalos, etc.  They aill circle around the youngsters and protect them from the lions.

Maybe it does not translate across the board, but it's similar.   I don't think it is hurting the overall survival of our species to be protecting these people.  I think as we have evolved, as humans, we have developed the cognitive ability to think, reason, feel compassion, etc.  I don't think there is anything wrong with that.