You don't even need that hypothetical for it to make sense. Look up how chimpanzees fight against each other for territory. It's survival of the fittest over millions of years, simple. Cold weather in the north, requiring the development of technology for survival, learning how to use fire to cook clean food, learning how to use alcohol to purify water, etc. We split from chimpanzees millions of years ago, and chimpanzees can only survive in very lush jungle areas because of the food sources they rely on, which is why they're endangered.