Unless you have an identical twin, there’s no one else in the universe with the exact same DNA as you. If life has a sanctuary, it’s within the nucleus, which contains our DNA… the ancient scripture of our genetic code. And it’s written in a language that all life can read. DNA is a molecule shaped like a long twisted ladder or double helix. The rungs of the ladder are made of four different kinds of smaller molecules which make up the letters of the genetic alphabet.
Particular arrangements of those letters spell out the instructions for all living things, telling them how to grow, move, digest, sense the environment, heal, reproduce. The DNA double helix is a molecular machine with about 100 billion parts called “atoms.” There are as many atoms in a single molecule of your DNA as there are stars in a typical galaxy. The same is true for dogs and bears and every living thing. We are, each of us, a little universe.
Tune in to Cosmos: Some of the Things That Molecules Do tonight at 10P on National Geographic Channel.