History of Medicine Rewriting the Book of Nature Charles Darwin and Evolutionary Theory Charles Darwin’s vision—“from so simple a beginning, endless forms most beautiful and most wonderful have been, and are being evolved”—now forms the foundation of the biological sciences. Radical in sweep, Darwin’s idea of naturally innovating and endlessly changing webs of life undercut all previous sciences. Darwin was instantly seen as a potent sign of a new science, a new way of conceiving the world. His theory was an immediate threat not just to those who were wedded to an older conception, but to all who relied on a given and settled order for meaning and for power. Emerging just as liberal reforms in western society seemed headed for radical explosion, just as technological change provided a social and economic motor that sped up life beyond all imagining, changes in science portended changes in society: “things fall apart; the center cannot hold.” Evolutionary theory laid bare deep connections within the living world—and implicated humanity as deeply as any species. Darwin rewrote the book of nature, and forced us to rethink our own place within it. That Darwin’s thought could be so fertile should not surprise us. On the Origin of Species evoked life in all its intricacy, fecundity, and creativity. This is the world that Darwin explored and surveyed, described and explained—his enduring legacy to science, and to us. 29 June 2011