"We are related not only to every living thing, but also to every thing that ever lived."
"The geologic time scale on the Great Tree of Life begins at the center bottom, at Earth's birth, more than four thousand million (4 billion) years ago. As you move away from this center point toward the outer margin of the tree, geologic time gets younger and younger, until at the outer curved edge of the tree you arrive at the present day. Times on the geologic time scale are shown at the base of the diagram in millions of years before present. These are traced through the tree of life along curved, dashed time lines. All points on a curved, dashed time line are of the same age. For example; any point on the dashed time line labeled '1000' represents a time 1000 million years (that's equal to one billion years) in the past. Similarly, any point on the outer margin of the tree represents time today. Any point on the tree of life can be placed in geologic time by using these curved time lines."
Fantastic diagram, Joan! That's a keeper.