Richard Dawkins

What do cells do when they see a broken piece of DNA? Cells don't like such breaks. They'll do pretty much anything they can to fix things up. If a chromosome is broken, the cells will repair the break using an intact chromosome.

The leg system of the beach animals works because of a combination of certain lengths of tubes. Because of the proportion of lengths, the animals walk smoothly. You could say that this range of numbers is their genetic code.