Human beings rule the animal kingdom when it comes to intelligence and emotional complexity, but our top-dog position might not be as stable as we think, at least when compared to our ancestors. Some researchers postulate that we may be regressing evolutionarily to a more, well, dumb state. Their argument: Our intellectual and emotional capabilities may be slipping away. The intricate web of genes that endow us with our brain power is particularly susceptible to mutations, and at the same time, our Snookie and Real Housewives-ridden society isn’t selecting against those deleterious changes. It’s not easy being smart, the researchers point out in a statement. In order for us to maintain our brains, we need optimal functioning of thousands of genes. Back in the day, our hunter-gather ancestors required intelligence for their ability to outwit potentially dangerous prey and survive in harsh environments, which exerted a selective pressure on the genes required for intellectual development. At this point, the researchers postulate, human intelligence probably peaked. From there, it was a slippery slope. Agriculture led to urbanization, so the evolutionary drive that weeded out mutations tied to intellectual disabilities likely lessened as life challenges softened and the margins of survival widened. Around 2,000 to 5,000 genes are required for intellectual ability, the researchers think, and over the past 3,000 years—about 120 generations—statistics say we’ve probably all sustained two or more mutations that dragged down our intellectual bar. Read more: http://blogs.smithsonianmag.com/sma...etting-intellectually-and-emotionally-stupid/
