Are we now going against nature in our reproductive habits?

Question

Nature uses differential reproduction and differential survival to eliminate all deleterious mutations thereby to keep the species healthy and vigourous. Apparently human species is moving against this by practising monogamy etc.

Answer 1

I don't believe we are going against nature. there are alot of species that mate for life we just happen to be one of them (well some of us)

Answer 2

Sure, but not just monogamy. We're also going against nature by keeping the sick, feeble and elderly going as long as possible with drugs, machines and lots of care (in the wild, they'd be left to die). I'm not audacious enough to say this is wrong exactly, but it ain't natural.