Q. SO BIG BRAINS ARE NOT ALWAYS AN ADVANTAGE?
A. Bigger is better if you want to produce enormously complicated behavior. But in evolution, brains evolve by selection. There always is pressure on animals to produce behaviors for as little energy as possible. And that means for many animals, smaller brains are better because they won’t waste energy.
You know, there’s this pervasive idea in biology that I think is wrong. It goes: we humans are at the pinnacle of the evolutionary tree, and as you get up that tree, brain size must get bigger. But a fly is just as evolved as a human. It’s just evolved to a different niche.
In fact, in evolution there’s no drive towards bigger brains. It’s perfectly possible that under the right circumstances, you could get animals evolving small brains. Indeed, on some islands, where there’s reduced flora and fauna, you’ll see smaller versions of mainland species. I would argue that their brain size has been reduced because it saves energy, which permits them to survive in situations of scarcity. They also might not need big brains because they don’t have natural predators on the islands—and don’t have to be as smart because there’s nothing to avoid.
also...
-- there’s this idea that nature moves inexorably towards bigger brains and some people find it very difficult to imagine why if you evolved a big brain — as ancient hominids had — why you would ever go back to a smaller one. But evolution doesn’t really care. This smaller brain could have helped this species survive better than an energy-consuming bigger one. The insects have shown us this.
im going to cite in mla format...just in case.
Dreifus, Claudia. "A Conservation with Jeremy Niven- Insects as Model Animals." New York Times 13 July 2010. Web. 13 July 2010.
