The varied life on earth is so complex in its interaction with the environment and amongst itself that often we do not
know where the organism ends and the environment begins. Such is the extreme complexity that some biologists consider
it more logical to think of the planet as a living organism. This is the Gaia Theory. It is instructive to think of the
living planet in terms of a giant cell; the complexity of a cell being an excellent metaphor for the living planet.
Then, we may also speculate the earth-cell to divide !