Rock Doc

My brother likes to build buildings in his free time. He has a couple of timber-frame structures on his property that he put up over the years, and now he’s working on a more traditional “stick” building made of 2x6’s and 2x4’s. One thing all of his efforts have in common is that they begin as drawings and become blueprints. And even though he’s built with quite different approaches over the years, all his buildings have some things in common: windows, doors, and stairs to name just a few.

Many scientists would say that life on Earth also has a complex but single blueprint. Many animals are “b...