Over the course of five editions, the ways in which biology is taught have dramatically changed. We have seen a shift away from the memorization of details, which are easily forgotten, and a movement toward emphasizing core concepts and critical thinking skills. The previous edition of Biology strengthened skill development by adding two new features, called CoreSKILLS and BioTIPS (described later), which are aimed at helping students develop effective strategies for solving problems and applying their knowledge in novel situations. In this edition, we have focused our pedagogy on the five core concepts of biology as advocated by "Vision and Change" and introduced at a national conference organized by the American Association for the Advancement of Science.