Quote Originally Posted by ataraxis View Post
We are growing taller, healthier, smarter, and ability to live much longer. This is all due to better nutrition and eventually leading to better genes which are being passed on. [/b]
It doesn't work like that. We are just realizing the potential that was already in our genes, not improving genes and passing on traits. That is Lamarckian evolution which has been disproved, not natural selection.

By saving individuals that would otherwise die, and with their subsequent reproduction, of course this increases the percentage of otherwise detrimental genes in the population. However, this also allows some possibly beneficial genes that these individuals may be carrying to be propagated as well. If some of their offspring inherit the "good" genes but not the "bad" genes, they and the population have benefitted. Think about if Stephen Hawking had a smart kid that didn't have the tendency to get the disease that he has.

OK, so the population expands and the weaker individuals survive and breed when times are good. This can be applied to any population, not just our current situation--humans are just an extreme example of this. Ultimately, there will be a contraction of the population due to die-off of some kind. In that case, the individuals who are the most fit for the new environment will be the ones to survive. This may include some individuals who were the product of the previous "good times" that allowed for even the weak to live, and who gained beneficial mutations from their less-than-perfect ancestors.

So, even tho there are traits amongst us that would have been selected against in a natural environment, it doesn't matter. It's not like they dilute the good genes so much that if some catastrophe causes natural selection to start working again, everyone will die. And it can allow for beneficial mutations that would otherwise have been lost to accumulate.