paraII: It works in reverse, too, for the inanimate portion of Earth is shaped and molded by life.
The enormous ocean reefs are formed by coral.
The nature of the atmosphere has been changed by plant activity
•etween 2 billion and 3 billion years ago, portions of the surface water, bathed by the energetic radiation from the sun, developed complicated compounds in organization sufficiently versatile to qualily as what we call "life". Life forms have become more complex and more various ever since.
Cells in those organs that suffer constant wear and tear—as in the skin or in the intestinal lining—grow and multiply all life long. Other cells, not so exposed, as in nerve and muscle, do not multiply at all in the adult, under any circumstances. Still other organs, ordinarily quiescent, as liver and bone, stand ready to grow if that is necessary to replace damage. When the proper repairs are made, growth stops.
