• The plow is one of the most ancient and most valuable of man's inventions; but long before he existed the land was in fact regularly plowed, and still continues to be thus plowed by earthworms. It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.

    Charles Darwin (1884). “Darwinism Stated by Darwin Himself: Characteristic Passages from the Writings of Charles Darwin”