Biology, 7th Edition

Book Preface

Charles Darwin described evolution as a process of “de-scent with modification.” It is a phrase that also fits the continuing evolution of BIOLOGY. This Seventh Edition s our most ambitious revision of the book since its origin— a new textbook “species” with several evolutionaI)1 adaptations shaped by the changing environment of biology courses and by the astonishing progress of biological research. But these adap-tive modifications are still true to the two complementary teaching values at the core of every edition of BIOLOGY. First, we are dedicated to crafting each chapter from a framework of key concepts that will help students keep the details in place Second, we are committed to engaging students in scientific in-quiry through a combination of diverse·examples of biologists’ research and opportunities for students to practice inquiry themselves

These dual emphases on concept building and scientific in-quiry emerged from our decades of classroom expe1ience. It is obviously gratifying that our approach has had such broad ap-peal to the thousands of instructors and millions of students who have made BIOLOGY the most widely used college sci-ence textbook. But with this privilege of sharing biology with so many students comes the respons扭lity to continue im-proving the book to serve the biology community even better As we planned this new edition, we visited dozens of campuses to hear what students and their instructors had to say about their biology courses and textbooks. What we learned from those conversations about new directions in biology courses and the changing needs of students informed the many im-provements you’ll find in this Seventh Edition of BIOLOGY

We have restructured each chapter to bring its key concepts into even sharper focus

The discovery explosion that makes modern biology so excit-ing also threatens to suffocate students under an avalanche of information. The past few editions of BIOLOGY set the deta让s in a context of key concepts, typically ten to twenty per chap-ter. In this new edition, we have taken the next evolutionary step of restructuring each chapter to help students focus on fewer, even bigger ideas— typically just five or six key con-cepts per chapter. A new Overview section at the beginning of each chapter sets an even broader context for the key concepts that follow. And at the end of each of the concept sections, a Concept Check with two or three questions enables students to assess whether they understand that concept before going on to the next. Answers to the Concept Check questions are located in Appendix A, as are the answers to the Self-Quizzes from the Chapter Review at the end of each chapter In our ongoing interactions wi.th students and instructors, they have responded enthusiasti ally to our new organization and pedagogy. Compared to other textbooks, including earlier editions of our own, students have found the new chapter structure and design of BIOLOGY, Seventh Edition, to be more inviting, more accessible, and much more efficient to use. But in achieving these goals, we have not compromised the depth and scientific accuracy the biology community has come to expect from us

New “Exploring Figures” provide efficient access to many complex topics

Mogyis a visual science. Thus we have always authored BIOLOGY’s graphics and narrative side by side Lo coordinate å½’rmessage. ln the Seventh Edition, this text-art integration reaches its next evolutionary level with a new「eaturecalled “Exploring Figures.” Each or these large figures is a learning unit that brings together a set of related illustrations and the text that describes them. The Exploring Figures enable stu- In Exploring Figures, art, photos, and text are fully integrated dents Lo access dozens of complex topics much more effi-ciently, now that the textual and visual components have merged. The Exploring Figures represent core chapter content, not to be confused with some textbooks'”boxes,” which feature content that is peripheral to the now of a chapter. Modern bi-ology is challenging enough without diverting students’atten-tion from a chapter’s conceptual storyline. Thus, each Explor-ing Figure is referenced in the main text body where it fits into the development of a concept, just as the text points students Lo all the other supporting figures at the appropriate places in the narrative