Perhaps just another example of genetic information, that is programmed in, but not used. Unused genetic info is found mostly in simpler creatures who have much of the same genetic info as humans. For example the sea urchin has the genetic info for a complex eye, and a sophisticated immune system. Isn't it interesting that this genetic info is found in the fossil record in the sea urchin 500 million years ago, yet the info was not expressed until hundreds of millions of years later in more complex creatures. Common designer?