We often try to give examples of evolution occurring right now, in order to answer the proposition from creationists that no one ever saw evolution happening. The commonest example we give is the development of antibiotic resistance in bacteria. However I recently saw a comment on a blog as follows: The blogger had taught a group of medical students that MRSA came about because of evolution in response to the selection pressures of antibiotic use, when a member of the group stood up and said 'That's a lie!' I asked her how she thought MRSA happened - 'It is a punishment from god'.
A better example might be within the ranks of evangelicals themselves (as the above story suggests). Intuitively it seems that the evangelicals are getting stupider and stupider, and evolutionary theory can certainly explain why this is happening. If you started off with a group of, say, 1000 people, who were suddenly converted to some new religion. If the group had the usual bell-shaped curve of intelligence (and I realize that this is a big if, but stay with me) then evolution within the group would begin almost immediately. The smarter members of the group would very soon realize that what they were being told about golden tablets or beings from another world was completely crazy, and they would leave. The average IQ of the group would then fall.
The dumbest members of the group would start believing crazier and crazier things -- virgins in heaven, spaceships behind comets -- and as a result some of the now smartest ones would leave. Conversely, as the beliefs became more and more mad-brained, new members from outside would inevitably be dumber and dumber.
Round and round the feedback cycle would go, the religious would become more and more addlepated, more resistant to any kind of rational thinking from outside, the intelligent would become atheists.
Just a theory of course, but it seems to fit the facts does it not?
David Horton's Watermelon Blog on the other hand just keeps getting more and more intelligent, as more and more smart readers arrive.