In a sense, evolution adheres to the classic twelve-step program: it takes things one day at a time. It does not strive for perfection; it does not strive at all. There is no progress, no plans, no scala natura, or scale of nature, that ranks organisms from lowly to superior, primitive to advanced.
Woman: An Intimate Geography (ed. Houghton Mifflin Harcourt, 1999) - ISBN: 9780547344997