With a new open, student-friendly layout and more media integration, the Fourth Edition of Biology of Humans: Concepts, Applications, and Issues continues to personalize the study of human biology. Its conversational writing style, stunning art, abundant applications, and learning tools develop your critical-thinking skills. The authors provide a conceptual framework to help you understand how our bodies work, and to deal with issues relevant to human health in today's world. You'll gain an appreciation for the intricacy of the human body and the place of humans in the ecosphere. This new edition is available with MasteringBiologyr.