Sean Carroll in Preposterous Universe:
One of the brilliant achievements of Darwin’s theory of natural selection was to help explain apparently “purposeful” or “designed” aspects of biology in a purely mechanistic theory of unguided evolution. Features are good if they help organisms survive. But should we put organisms at the center of our attention, or the genetic information that governs those features? Arvid Ågren helps us understand the attraction of the “selfish gene” view of evolution, as well as its shortcomings. This biological excursion has deep connections to philosophical issues of levels and emergence.