The "Tree of Life" is a
biological term reflecting the shape of
evolution through the
passage of time. It begins with the
trunk, the
universal ancestor of life on earth; splits into its major branches,
animals,
plants,
fungi and so on; splits again into smaller branches,
mammals,
birds,
reptiles, and
amphibians within the
vertabrates; all the way out to the very tips of the branches which represent each individual
species.
The Tree of Life represents evolution unfolding through time; the most ancient life begining at the trunk, and the most recent in the twigs.