let's not miss out on the genetics factor while we're at it. There are people who are prone to certain illnesses and even though 2 people are tested to determine whether they are prone to a disease or not, and they both turn out positive, they still go ahead and have kids. This....damages (for lack of a better term) the gene pool allowing those with the genes prone to illnesses to continue to reproduce.
When natural selection was allowed to take its course, those who were prone to disease, died off. Leaving those with a natural resistance to disease to reproduce and strengthen the gene pool. Now with modern medicine we have eliminated this natural selection.
There was a joke video going around youtube about a wealthy intelligent couple not being able to have kids and then an idiot family living in a trailer having 10......
This has a dramatic/exponential impact on our environment as well. Think of it this way: if natural selection were allowed to do its thing, there'd be less air pollution due to less people requiring cars, electricity, natural resources etc.
No insult to bliss, but if we allowed those who got cancer to die off, eventually no one would get cancer any more. Same as all other supposedly "incurable" diseases......
Substitute "cancer" for baldness. How many families do you know where every male in the family over 30 is bald or losing their hair? I've been close to families where everyone is healthy and they've never had any serious illness. As far as I know, anyone for 3 or 4 generations have all just died of old age......
Oh yeah, one BIG factor no one has mentioned yet:
Background radiation. How many nuclear tests have been done above ground? Anyone remember this big radioactive cloud after chernobyl? Or the recent radiation dump caused by japan's reactor going critical?
Anyone ever watched a NASA launch? Look at all the SHIT (highly toxic) that those rockets create and with the space shuttle, most of that just falls into the ocean (where it enters the food chain).
I mean really, they are finding so many species of fish with extremely high mercury poisoning.....