Preface
Since the First Edition of Principles of Life was published, the surge in biology education research and the availability of resources for teachers continues to create excitement among the teaching community. Just as the First Edition appeared, the American Association for the Advancement of Science (supported by the National Science Foundation) published Vision and Change in Undergraduate Biology Education: A Call to Action. This report endorsed teaching core concepts and core competencies, and promoted the active involvement of students in problem-solving activities. When the First Edition of Principles of Life was published, it offered a radically new approach to teaching introductory biology that aligns with the goals put forward in the Vision and Change report (see below).
Principles of Life emphasizes mastering major concepts in biology through active learning, problem solving in realistic scenarios, and understanding rather than memorization. Now other textbook authors are beginning to follow our lead. We are proud that Principles of Life has helped to usher in this change in the way biology courses are taught, and we intend to continue to develop our book as the leading vehicle for this new approach to biology education.
We are standing at an important crossroads in biology education, and many recent efforts have converged to produce an opportunity for lasting change in the way that instructors teach introductory biology. The validity of our approach in Principles of Life is supported by numerous reports and studies published by education agencies and national study groups since the turn of the millennium. In particular, two major reports have encouraged this change: the Vision and Change report mentioned above and BIO2010: Transforming Undergraduate Education for Future Research Biologists, sponsored by the National Institutes of Health and the Howard Hughes Medical Institute. These reports recommended focusing on core concepts and competencies, teaching students through active learning rather than memorization, and improving the integration of statistical and computational approaches. At about the same time, the College Board was redesigning the Advanced Placement Biology course with the same objectives. In Principles of Life, we have used our experience as authors and educators to implement these recommendations in a new approach to teaching introductory biology.
The Vision and Change report (2011) identified five “core concepts for biological literacy” that should be integrated throughout the curriculum. These core concepts center around the themes of:
In the Second Edition of Principles of Life, we have worked to ensure that these five core concepts are stressed and reinforced throughout the text, problems, media links, and other activities. To help students build bridges between different portions of the course and areas of knowledge, we have provided Links throughout the book. Using these Links, students can see, for example, that information they learn about molecular or cell biology is connected to topics in evolution, diversity, physiology, and ecology.
In addition to urging a focus on core concepts, the Vision and Change report argued that students need to cultivate certain core competencies to become successful scientists. Students should be able to:
Students are encouraged to practice these core competencies throughout the Second Edition of Principles of Life. Every chapter contains Apply the Concept exercises, which give students opportunities to practice working with data. These problems tie in with our Making Sense of Data: A Statistics Primer (Appendix B), which helps students understand why and how biologists draw conclusions from biological data, and thus helps them develop quantitative reasoning skills. We have also added more online Animated Tutorials and Activities, which include opportunities for students to use modeling and simulation modules to further reinforce their understanding of concepts. By engaging in these activities, students also learn about the importance of biological concepts and analyses for addressing societal issues and challenges.
Prior to our launch of the First Edition of Principles of Life, introductory biology textbooks for science majors presented encyclopedic summaries of biological knowledge. We believe that students who spend their time diligently memorizing myriad details and vast terminology actually retain fewer of the concepts that are the foundation for further study in advanced courses. In Principles of Life, we take the opposite approach: we promote understanding over memorization. Details are important, but no modern biology textbook can begin to cover all the information biologists have learned to date, and students today have many other ways to access the details as they need them.
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To help us create this new breed of biology textbook, in 2009 our publishers Sinauer Associates and W. H. Freeman brought together an Advisory Board of 20 leading biology educators and instructors in introductory biology from throughout North America. During an intensive meeting of the authors and the Board, dynamic discussions led to the solidification of the core concepts we believe are essential for teaching introductory biology. The book took shape, and the Advisory Board members then reviewed the emerging chapters and provided considerable feedback at every stage of the book’s development. The result was a book that showcased the logical structure of scientific investigation, including lab, field, and computer modeling approaches. Principles of Life helped students apply the concepts they learn by providing opportunities for them to analyze original data in every chapter. In this and many other ways Principles of Life incorporated inquiry-based approaches that encourage active learning.
The First Edition of Principles of Life was widely adopted and well received. Adopters and reviewers praised the approach, and encouraged us to expand the effort to include even more problem-solving opportunities for students and more examples of the experiments that have formed the basis of our understanding. For the Second Edition, all chapters underwent extensive between-edition review by experts in each respective subdiscipline, and the chapters were revised accordingly. We now provide more references to original data and analyses so that students and instructors can easily explore the original experiments in greater depth. Moreover, we have expanded opportunities for students to apply what they have learned by using real data and examples, and have better integrated and explained the concepts of statistical analysis of data. We have included links to online videos (the new Media Clips) that help students to appreciate the relevance of what they have learned and to enjoy the excitement of biology.
Each chapter of Principles of Life is organized into a series of Concepts that are important for mastering introductory biology. We have carefully chosen these concepts in light of feedback from our colleagues, from the Advisory Board, and from the numerous reports examining introductory biology. Concepts are elaborated upon, but not with the extensive detail found in most introductory texts. Principles of Life is focused; it is not meant to be encyclopedic.
Students learn concepts best when they apply them to practical problems. Each chapter of Principles of Life contains exercises, called Apply the Concept, that present data for students to analyze. Each of these exercises reinforces a concept that is central to that chapter. Science students need to understand basic methods for data presentation and analysis, so many of these problems ask students about statistical significance of the results. To help students understand issues in data presentation and interpretation, we have provided a short introduction to the reasoning behind biological statistics in Appendix B. Although this Appendix is not meant to replace a more formal introduction to statistics, we believe that statistical thinking is an important skill that should be developed in all introductory science courses. We have kept the problems and examples straightforward to emphasize the concepts of statistical analysis rather than the details of any particular statistical test. Some of the Apply the Concept exercises are simple enough that they can be presented, analyzed, and discussed in class; others are better suited for homework assignments.
Our Investigation figures let students see how we know what we know. These figures present a Hypothesis, Method, Results, and Conclusion. Most of these Investigation figures now include a section titled Analyze the Data, in which we have extracted a subset of data from the published experiment. Students are asked to analyze these data and to make connections between observations, analyses, hypotheses, and conclusions. As with Apply the Concept problems, students are asked to apply basic statistical approaches to understand the results and draw conclusions. We have also provided original references and extensive online resources for each Investigation figure. The online resources are available in LaunchPad, Principles of Life’s new online platform. These resources include expanded discussions of the original research, links to the original publications, and discussion and links for any follow-up investigations that have been published.
Each chapter begins with an application of a major concept—a story that illustrates and provides a motivation for understanding the chapter’s content, and provides a social, medical, scientific, or historical context for the material. Each of these vignettes ends with an open-ended question that students can keep in mind as they read and study the rest of the chapter. We return to this opening question at the close of the chapter to show how information presented throughout the chapter illuminates the question and helps provide an answer. By pondering these questions as they read and study, students can begin to think like scientists.
At the end of each conceptual discussion we provide Checkpoints designed to help students self-evaluate their understanding of the material. These Checkpoints span the incremental levels of Bloom’s Taxonomy of Cognitive Domains: factual knowledge, comprehension, application, analysis, synthesis, and evaluation.
Another important element for student success is reinforcement and application of concepts through online Animated Tutorials, Activities, and Media Clips. Each chapter contains instant access codes (in the form of both a direct URL and a Quick Response, or QR, code, a barcode students can scan with a smartphone or tablet) that allow students to quickly access these online resources while reading. For many concepts, students can conduct their own simulations, explore a concept in greater depth, and understand concepts through active discovery. Using the Media Clips, they can also watch videos that help explain concepts or introduce students to the wonders of biological diversity.
Students need to learn about some of the major Research Tools that are used in biology, including major laboratory, computational, and field methods. Our Research Tools figures explain these tools and provide a context for how they are used by biologists.
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Our art program for Principles of Life continues to build on our success from Life: The Science of Biology. We pioneered the use of balloon captions to help students understand and interpret the biological processes illustrated in figures without repeatedly going back and forth between a figure, its legend, and the text. These guides help students connect critical points of figures to the concepts that are developed in the text.
The Second Edition of Principles of Life features an expanded collection of online resources to support and reinforce the material covered in the textbook. In an effort to more closely link the printed book to the online resources, you will find references with instant access (QR) codes and direct Web addresses for all of the new Media Clips, Animated Tutorials, Activities, and Interactive Summaries throughout the book. These allow students to link instantly to these resources from any device—computer, smartphone, or tablet—while reading the book.
The new LaunchPad online platform integrates all of the student resources, instructor resources, the complete eBook, and all assessment tools within a streamlined interface that groups essential content into easily assignable learning units. LaunchPad features a range of assessment tools including the new LearningCurve adaptive quizzing engine, and pre-built summative quizzes for each chapter. To support course preparation, classroom sessions, and assessment programs, there is a wide range of instructor resources available, including multiple versions of all textbook figures, a wealth of PowerPoint resources, multiple banks of assessment questions, a large collection of videos, and in-class active learning exercises.
For a complete list of all the media and supplements available for Principles of Life, please refer to “Media and Supplements to accompany Principles of Life” following this Preface. Also, please refer to the inside front cover for a full list of the student media resources referenced in the text.
Many people contributed to the creation of the Second Edition of Principles of Life (see below). However, two individuals deserve special mention for their contributions. Susan D. Hill did a masterful job in writing Chapter 38 on Animal Development. Nickolas Waser worked extensively with Mary Price on the Ecology section (Part 7), and was otherwise intimately involved in discussions of the book’s planning and execution.
In addition to the many biologists listed on the next page who provided formal reviews, each of us benefitted enormously from personal contacts with colleagues who helped us resolve issues and made critical suggestions for new material. They are: Walter Arnold, University of Veterinary Medicine (Vienna); Harry Greene, Cornell University; Will Petry, University of California, Irvine; David Sleboda, Brown University; Thomas Ruf, University of Veterinary Medicine (Vienna); Andrew Zanella, The Claremont Colleges; Edward McCabe, University of Colorado and the March of Dimes Foundation; and Frank Price, Utica College.
Our editor and publisher, Andy Sinauer, embraced the need for change in introductory biology textbooks and has helped make our vision into a reality. Bill Purves, Gordon Orians, and Craig Heller, our co-authors on earlier editions of Life: The Science of Biology and/or Principles of Life, were instrumental in articulating the concepts developed in this Second Edition of Principles of Life, and many aspects of this book can be traced back to their critical contributions.
For this new Edition, Sinauer Associates assembled a talented duo, Laura Green and Danna Niedzwiecki, who coordinated the editorial team and did much of the developmental editing. Annie Reid and Carol Pritchard-Martinez worked to ensure that the level and terminology are appropriate for beginning undergraduate students. Jane Murfett also contributed to developmental editing. Laura and Danna worked closely with a top-notch copyeditor, Liz Pierson. Carol Wigg was the principle production editor on previous editions of Principles of Life and Life: The Science of Biology and her mark endures. Elizabeth Morales, our artist, again worked with each of us to create effective and beautiful line art. She also revised many figures to make them more effective for people with common forms of color blindness. David McIntyre again rose to the challenge of finding new, even better photographs. Designer Joan Gemme brought a fresh look to the book and did a fine job of assembling all of the book’s elements into clear and attractive pages. Chris Small coordinated production and imposed his exacting standards on keeping the myriad components consistent. Johannah Walkowicz organized and commissioned the many expert academic reviews. Jason Dirks coordinated the team that created the vast array of online media and supplements. Dean Scudder, Director of Sales and Marketing, and Azelie Fortier, Biology Acquisitions Editor, participated in every stage of the book’s development.
At W. H. Freeman, we continue to benefit from the long-term input of Biology Publisher Susan Winslow. John Britch, Director of Marketing, in collaboration with the Regional Specialists, Regional Sales Managers, and the Market Development team, coordinated all the stages of informing Freeman’s skilled sales force of our book’s story. We also wish to thank the Freeman media group for their expertise in producing LaunchPad.
David M. Hillis
David Sadava
Richard W. Hill
Mary V. Price
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