Is the human brain still evolving?

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When we daydream about the future, we tend to focus on the fabulous belongings we're going to have. Jet packs, flying cars, weapons to kill aliens, cell phones that make today's sleek models look clunky -- you name it, we're going to have it. We don't tend to focus, however, on who we'll be in the future. Most of us probably picture ourselves exactly the same, though maybe thinner, as surely we'll all have robot personal trainers by then. While we see the world's technology evolving to meet our needs, we may not think about how we ourselves might be evolving.­

­The story of evolution up to this point explains how we became the upright walking, tool-using homo sapiens of today. The turning point of this story so far concerns cranial expansion. About 2.5 million years ago, hominids started out with a brain weighing approximately 400-450 grams (approximately 1 pound), but around 200,000 to 400,000 years ago, our brains became much bigger than those of other primates [source: Kouprina et al.]. Now, we humans walk around with brains tipping the scales at 1350 to 1450 grams (approximately 3 pounds) [source: Kouprina et al.].

­As humans, we enjoy a much larger neocortex. This area of the brain is the key ingredient that separates us from other species -- it allows us to do our deep thinking, make decisions and form judgments. And while our brain has served us well so far, it certainly has a few defects we wouldn't mind eliminating, like disease, depression and the tendency to make drunken phone calls at 2 a.m. to an ex-boyfriend. But until recently, scientists thought that we were done evolving, that we had reached a sort of evolutional apex. Now, though, some researchers think that we're not quite done.

Could our brains be evolving right now? Could we gain the intelligence to make our dreams of the future come true, or will we return to the hominid state of yesteryear? Go to the next page to find out if brain evolution is possible.