““We humans look rather different from a tree. Without a doubt we perceive the world differently than a tree does. But down deep, at the molecular heart of life, the trees and we are essentially identical. We both use nucleic acids for heredity; we both use proteins as enzymes to control the chemistry of our cells. Most significantly, we both use precisely the same code book for translating nucleic acid information into protein information, as do virtually all the other creatures on the planet.* The usual explanation of this molecular unity is that we are, all of us—trees and people, angler fish and slime molds and paramecia—descended from a single and common instance of the origin of life in the early history of our planet.””