Humans Are Becoming Dumber. Or Not.
It's easy to think that evolution has a purpose, that it optimizes design in some predictable, self-evidently appealing way. On the grand scale, this is probably true: evolution filled a dead, ammonia-choked Earth with biological processes that run on water and sunlight, and should keep going for the next few billion years. On a narrower scale, though, evolution's outcomes aren't necessarily for the better. They might even be for the worse.
Take human intelligence. According to geneticist Gerald Crabtree of Stanford University, humanity is, for reasons involving the genetic architecture of intelligence and the nature of modern life, becoming emotionally and intellectually dumber. Crabtree thinks we reached a peak several thousand years and have declined ever since.
This is, to be sure, just a hypothesis unsupported by data, and one that's received much criticism. But even if Crabtree is wrong, his argument makes for an enjoyable read.
"A hunter–gatherer who did not correctly conceive a solution to providing food or shelter probably died, along with his/her progeny," wrote Crabtree in Current Biology, "whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate."
Image: Eliot Phillips/Flickr