As population pressures continue to increase in our modern consequence-insulated environment, the evolutionary drive to stem the population growth will become manifest the way it always has in the absence of plague or famine: through war, mass murder, and genocide. But first, divisions must be found and claims must be staked in order to have something to fight over.
A few years ago, I was having a political discussion with a professional acquaintance. He's older and conservative, wealthy and considers himself self-made even though he started his business with his father's money. But I still respected him, and our conversation was civil and intellectual. He considers himself a libertarian and was, as always, complaining about big govt and taxes. So I asked him, what do you want from govt? You're not anarchist, right? Of course not, he said. So what do really want from govt? And he said (and yes I do quote) that what he wanted was for the govt "to put more people to sleep." I was a little confused, and asked if he meant the death penalty for criminals. To which he agreed, but then he said, "more than that... some people just don't belong here.. they're a drag on society, and I think that the govt should be able to put them to sleep." I was a little taken aback by this, but recovered and said, I feel certain that the people that you want the govt to put to sleep won't think that that's the actions of a small govt.
We've never had another political conversation since.