How to Become a Whale

Certain Darwinian explanations remind me of a favorite Monthy Python skit, "How To Do It." As a peppy, earnestly grinning host of a mock children's TV program, John Cleese opens up:

Well, last week we showed you how to be a gynaecologist. And this week on "How to Do It" we're going to learn how to play the flute, how to split the atom, how to construct box girder bridges and how to irrigate the Sahara and make vast new areas cultivatable.

First, though, Cleese introduces Eric Idle as...