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.
But the future will probably come to the rescue, the researchers think. Our intelligence loss is quite slow compared to society’s rapid advances, so not-too-distant technologies should eventually reveal each of the millions of human mutations that can compromise intellectual functions. ”At that time, we may be able to magically correct any mutation that has occurred in all cells of any organism at any developmental stage,” the researchers speculate. “Thus, the brutish process of natural selection will be unnecessary.”
In the meantime, we should probably get busy putting our remaining intelligence quotas to use in order to devise those smarts-saving technologies.
Artículo original en el Smithsonian.com