You don't want to confuse 'stronger and smarter' with 'the fittest.' Chickens aren't particularly strong and aren't particularly smart. I suspect whatever wild cousins they have beat them out on both strength and intelligence, yet good luck matching the numbers of domesticated ones. Of course, Louis has already suggested the very concept of 'the fittest' may not mean much, since its definition is pretty circular. Anyhow, strength and intelligence are not necessary for biological success. Successful reproduction is the measure.

Ajax
You mean faster reproduction as well. And im talking about how people are growing taller, supposedly smarter, etc.

But i walk into my calculus class and i'm not so sure.

Basically im saying weaker genes are being passed along because of science. Now this isnt a bad thing all people deserve to live but the results are what they are. Even reproduction isnt fail safe with tihngs like artificial insemination.