The+Universal+Tree+of+Life

The Universal Tree of Life Have you ever been to Disneyland? If so, did you see the Lion King version of the tree of life? (If not, here's a picture.) Well, however beautiful that tree of life is, it is nothing compared to the actual thing.

Scientists in the 1960s discovered something that links all life forms together. They found that every form of life shares one thing: a genetic code. If every living thing has something in common, the reasonable conclusion would be that there was a single origin of life from which everything branched out of.

There are two criteria scientists use to demonstrate the branching pattern of said tree: regions of DNA must be able to be sequenced, and they must have evolved so very slowly that similar structures can be seen in even the most distant organisms.

The book tries to make to main points about the tree of life.
 * 1) The tree of life consists of three huge domains: Bacteria, Archaea, and Eukarya.
 * The domain Bacteria houses most prokaryotes.
 * The domain Archaea has a large variety of prokaryotic organisms that live in many different places.
 * The domain Eukarya holds all organisms that have cells which contain true nuclei.
 * 1) And the early history of said domains is not clear.