The Panda’s Thumb

Stephen Jay Gould’s essay by the same name describes the unusual bone structure of the gentle animals.  Pandas do not actually have opposable thumbs, but rather one of their wrist bones is shaped in such a way that it looks like a thumb.  Since the ankle bones are also shaped like this, and the shape of ankle and wrist bones is controlled by the same gene, it appears this “thumb” was a result of random mutation.

The advantage that comes with the “thumb” is that pandas can eat their food of choice, bamboo, with an efficiency other animals cannot match.

Watch for this pattern: evolution is pretty much always driven by food or sex.