um actually the ethnicities I personally dislike are R-selected.

r and K selection models just refer to the relative number of offspring produced each generation and the number that make it to maturity; it's not really adequate to explain what happens when a species crosses over the carrying capacity line. It's also not particularly useful for a species (like ours) that's operating outside of ecological boundaries. Overpopulation is not an issue per se because we can't assume that each individual in the human population is consuming roughly equal amounts of resources, so population growth doesn't necessarily predict resource consumption growth.

I don't really think this logic works under capitalism and the existence of modern farming. In any case, K selection implies the immiseration of millions after we've fucked the climate and drank all the water

What happens when humans are consuming the planet's resources faster than the replenishment rate. It's a concept called overshoot and we are currently in overshoot.