Cecie Starr and Ralph Taggart are among the most successful authors in introductory, biological science instruction because of their lively approach, engaging writing style, current coverage of the breadth of biology's topics, and their unique illustrations. In this Tenth Edition of Biology: The Unity and Diversity of Life, the authors use the important connections among molecular structure, biological function, and evolution to encourage student understanding instead of memorization. For example, Chapter 1 includes a preview of life's unity and diversity with an evolutionary perspective. Similar sections in Chapters 3, 5, and 6, on the structure and function of enzymes and other molecules, prepare students for chapters on cell structure and metabolism, genetics, evolution, anatomy, and physiology. This background prepares students to understand the power of comparative molecular studies in clarifying evolutionary relationships. Connections essays (28 in all) focus on this new integration of molecular structure, function, and evolution. The first essay (1.4) answers an important question: How can life display both unity and diversity? It shows how the theory of evolution by natural selection connects the two. Other essays consider evolutionary interplays between infectious agents and their hosts; cloning and genetically engineered mammals, the evolution of life over the past 3.8 billion years, and archaeopteryx and the ancestry of whales (to show that interpreting the past scientifically requires an intellectual shift). Improvements in the media package meet the high standards instructors have come to expect. There is a new version of the complimentary Interactive Concepts in Biology Student CD-ROM with nearly 800 interactions to clarify and reinforce key concepts. For instructors, there is a Multimedia Manager with art and graphics from the text already in PowerPoint format, as well as CNN Today video clips (294 in all), now available digitally.