Book excerpt: Human Biology, Sixth Edition, provides students with a clear and concise introduction to the general concepts of mammalian biology and human structure and function. With its unique focus on health and homeostasis, Human Biology enhances students' understanding of their own health needs and presents the scientific background necessary for students to think critically about biological information they encounter in the media. The completely revised content and exceptional new art and photos provide students with a more user-friendly text, while excellent learning tools maximize comprehension of material.