It's not about species as a whole. It's about the genes. The genes need time to propagate. You cooperate, you'll likely stay alive longer. You don't do risky shit, you'll probably stay alive longer. You don't do anything, you'll probably die but not because of risk but inaction. You fuck like crazy and be risky, you might die at 23, but your genes might have propagated. Your kids might have the same tendencies and risky behavior, so you might preselect your offspring for early death but still propagate. Your dna stays alive, even if your 'key to success' is to die young. (For example)

There are all kinds of variations possible. Competition can be a selector, but not necessarily a sensible one for many circumstances. Being good at climbing may be a useful selector if you live in the mountains, but may fail to deliver benefit in other cases.

This isn't a zero sum game. You all may survive way better, easier, in a more comfortable and pleasant society by simply cooperating.

Let's be clear, *nothing* about natural selection *requires* greed or "at-the-cost-of-everyone-else" attitude. That's not how natural selection operates. (Please note that 'evolution' is merely about genes changing therefore opening up to change.)

As a side-note: see Darwin Awards. 😋