The year 2009 marked the 200th anniversary of Charles Darwin’s birth and the 150th anniversary of his most influential publication (Darwin, 1859). Darwin transformed the biological sciences in much the same way that Nicolaus Copernicus, Galileo Galilei, and Isaac Newton had transformed the physical sciences—by demonstrating that the universe operates according to natural laws that fall within the purview of rational scientific inquiry. In 1543, Copernicus published De revolutionibus orbium celestium (“On the Revolutions of the Celestial Spheres”) which challenged conventional wisdom that the Earth was the center of Creation, and instead promoted the idea that natural laws govern the motion of physical objects in the universe. More than three centuries later, in The Origin of Species, Darwin developed the equally revolutionary concept that a natural but nonrandom process—natural selection—can yield biological adaptations that otherwise exude the superficial aura of direct craftsmanship by an intelligent agent.
This book is the outgrowth of the Arthur M. Sackler Colloquium “The Human Condition,” which was sponsored by the National Academy of Sciences on December 11–12, 2009, at the Academy’s Arnold and Mabel Beckman Center in Irvine, California. It is the fourth in a series of colloquia under the umbrella title “In the Light of Evolution.” The first book in this series was titled In the Light of Evolution, Volume I: Adaptation and Complex Design (Avise and Ayala, 2007). The second was In the Light of Evolution, Volume II: Biodiversity and Extinction (Avise et al., 2008). The third book—In the Light of Evolution, Volume III: Two Centuries of Darwin (Avise and Ayala,