One might be tempted to assume that if the human specie evolved as so blatantly non-Bayesian, yet survived and took over the world, then Bayesianism is probably incorrect. Because if it was, then surely any specie that would have evolved Bayesianism would have taken over the world instead of us. If we have this in mind, that should take care of the "be vs ought" fallacy, because what ought to be, would be.

I reject this argument however, mainly because Bayesian calculations are simply intractable. Even when they are, "Yikes! A tiger!!" is way more effective at Darwinism than the more explicit "Yellow, stripes, feline shaped, looking at me, big, danger so let's -AHRRGH CRUNCH GULP". And the fair amount of false positives that the emotional quick guess generates probably wasn't very harmful in the ancestral environment.