I can picture protohumans having a use for larger canine teeth but what would they need significantly larger molars for?
It's not really about need, it's about just one of those things. :') As omnivores, humans eat a very wide variety of foods, and so we have a wider variety of less specialized dentition. :') Hey, I'm 46 and that's the first time I'd used dentition in a sentence. And that was the second. Oooh, witnessing history here, I'm all a-tingle.