Joined: May 2002
Don't think this has been posted before:
Dean, Anthony (1998). The Molecular Anatomy of an Ancient Adaptive Event. American Scientist, 86(1), p. 26.
Not long ago after the first living organisms appeared on earth about 3.5 billion years ago, they started undergoing mutations and adaptations. One of the very earliest of these created two enzymes, each with distinct but related functions, where only one previously existed. Using a combination of the modern techniques of structural biochemistry and protein engineering, combined with molecular phylogeny, the author recreates the story of this very ancient event.
The article is about the origin of two ancient proteins from a common ancestor (enzymes that handle NAD or NADH) and is quite detailed but also written for the nonexpert. I believe Ken Miller has used the technical paper it was based on as an example. It is now freely online at American Scientist.
Adding this also to the EvoWiki page on the evolution of new information.