I think in the context of machine learning the brain's ability to model the real world has evolved and a better model for the world represents a survival advantage. I don't know too much about how the brain actually models reality (and I don't know if anyone does) but the theory of machine learning still applies in the sense that each individual brain of each animal is a model and if you have a model that is too complex it will generalize poorly and therefore the owner of that brain is likely to do poorly in the real world.

It's very interesting in the sense that the totality of brains over time is essentially a sort of supervised learning with huge amounts of input data.