Evolutionists like Dawkins pose that most organisms are in fiercest competition with members of their own species. You and I compete for identical resources: mates, jobs etc.
Other species have mostly arranged not to kill one another in these competitions. E.g. vipers & komodo dragons don't bite while wrestling. Walruses get pretty ripped-up, but usually don't die.
Ganging up to kill seems to be mostly a primate thing.
Male lions will kill cubs fathered by another male without remorse. It is not the same as our primate instincts of war, but remarkably close to ethnic cleansing.
