What the World Needs Now: Smarter Flies?

Actually, yes. According to this NYTimes article on animal learning, some scientists bred flies to be smarter. That's a revelation--flies do learn. And then they determined that smarter flies had shorter lives. The general argument is that while there are benefits to being able to learn, there are also costs. (As Robert Heinlein would say, there's no such thing as a free lunch.) It's not quite clear where the costs come from, though if the young have to learn by experience, they're more vulnerable than if they were hard-wired. And brains are costly in terms of energy. (That's why there are so few in evidence these days.)