I'm not a big SF fan but that story is the first thing that came to mind. The premise is that we're getting dumber because the dumber segments of the population are indiscriminately breeding faster, and there's probably some real truth to that.
The interesting counterpoint is that IQ scores have generally been increasing over generations, to the point that IQ tests have to be revised once in a while, a phenomenon sometimes called the Flynn effect. But this effect is far too rapid to be genetic in origin, and there's some evidence that it's flattened out in developed countries. Among the explanations for it, the most likely IMHO is a combination of better test-taking proficiency as a result of better education, and environmental improvements, particularly the reduction of neurotoxins in the environment (elimination of lead from lead paint and gasoline, reduction of other heavy metals from coal emissions, etc.). So it has nothing to do with long-term evolutionary improvement of intelligence.
said by ekster:
"You don't get Stephen Hawking 200,000 years ago. He just doesn't exist," Hills told LiveScience. "But now we have people of his intellectual capacity doing things and making insights that we would never have achieved in our environment of evolutionary adaptation."'
He existed, he just wasn't relevant. Adaptive evolution through natural selection is the only kind of evolution there is. We live in a cocoon of civilization that has brought human biological evolution to pretty much a dead halt. We get occasional geniuses like Einstein and Hawking, but they have no evolutionary advantage.--
"Everyone is entitled to their own opinion, but not their own facts."
Daniel Patrick Moynihan