No one who teaches biology today can fail to appreciate how important a subject it has become for our modern world. From global warming to stem cell initiatives to teaching intelligent design in classrooms, biology permiates the news, and in large measure will define students’ futures. As a teacher, I have stood in front of classrooms for over 30 years and attempted to explain biology to puzzled and sometimes uninterested students, an experience that has been both fun and frustrating: Fun because biology is a joy to teach, rich in ideas and interesting concepts, and increasingly key to many important public issues; frustrating because in every biology class there are always some students who will not pay attention, who not only miss out on the fun but also fail to acquire a tool that will be essential to their futures.

This text, Essentials of The Living World, is my attempt to address this problem. It is short enough to use in one semester, without a lot of technical details to intimidate wary students. I have tried to write it in an informal, friendly way, to engage as well as to teach. The focus of the book is on the biology each student ought to know to live as an informed citizen in the 21st century. I have at every stage addressed ideas and concepts, rather than detailed information, trying to teach how things work and why things happen the way they do rather than merely naming parts or giving definitions.

Focusing on the Essential Concepts

More than most subjects, biology is at its core a set of ideas, and if students can master these basic ideas, the rest comes easy. Unfortunately, while most of today’s students are very interested in biology, they are put off by the terminology. When you don’t know what the words mean, it’s easy to slip into thinking that the content is difficult, when actually the ideas are simple, easy to grasp, and fun to consider. It’s the terms that get in the way, that stand as a wall between students and science. With this text I have tried to turn those walls into windows, so that readers can peer in and join the fun.

Analogies have been my tool. In writing Essentials of The Living World I have searched for simple analogies that relate the matter at hand to things we all know. As science, analogies are not exact, but I do not count myself compromised. Analogies trade precision for clarity. If I do my job right, the key idea is not compromised by the analogy I use to explain it, but rather revealed.

There is no way to avoid the fact that some of the important ideas of biology are complex. No student encountering photosynthesis for the first time gets it all on the first pass. To aid in learning the more difficult material, I have given special attention to key concepts and processes like photosynthesis and osmosis that form the core of biology. The essential processes of biology are not optional learning. A student must come to understand every one of them if he or she is to master biology as a science. A student’s learning goal should not be simply to memorize a list of terms, but rather to be able to visualize and understand what’s going on. With this goal in mind, I have prepared nearly two dozen “this is how it works” Essential Biological Process illustrations explaining the important concepts and processes that students encounter in introductory biology. Each of these Essential Biological Process illustrations walks the student through a complex process, one step at a time, so that the central idea is not lost in the details.

Teaching Biology as an Evolutionary Journey

This text, and its companion concepts text The Living World, were the first texts to combine evolution and diversity into one continuous narrative. Traditionally, students had been exposed to weeks of evolution before being dragged through a detailed tour of the animal phyla, the two areas presented as if unrelated to each other. I chose instead to combine these two areas, presenting biological diversity as an evolutionary journey. This has proven a very powerful way to teach evolution’s role in biology, and today you would be hard pressed to find a text that does not organize the material in this way.

Evolution not only organizes biology, it explains it. It is not enough to say that a frog is an amphibian, transitional between fish and reptiles. This correctly organizes frogs on the evolutionary spectrum, but fails to explain why frogs are the way they are, with a tadpole life stage and wet skin. Only when the student is taught that amphibians evolved as highly successful land animals, often as big as ponys and armour plated, can students get the point: Of 37 families of amphibians, all but the three that lived in water (frogs, salamanders, and caecilians) were driven extinct with the advent of reptiles. A frog has evolved to invade water, not escape it. It is in this way that evolution explains biology, and that is how I have tried to use evolution in this text, to explain.

Linking Essentials Concepts to Everyday Life

One of the principal roles of nonmajor biology courses is to create educated citizens. In writing Essentials of The Living World I have endeavored to relate what the student is learning to the biology each student ought to know to live as an informed citizen in the 21st century. Students also engage much more actively in the course when they can see how what they are studying relates to their own everyday lives.

Throughout the text, Essentials of The Living World presents full-page connections, readings written by the author that make connections between a chapter’s contents and the everyday world: Biology and Staying Healthy discusses health issues that impact each student; Today’s Biology examines advances in biology that importantly affect society; A Closer Look examines interesting points in more detail; and Author’s Corner takes a more personal view (the author’s) of how science relates to our everyday lives.

It is impossible to thumb through the pages of this new edition without seeing the second way Essentials of The Living World links what a student is learning to the world that the student knows. In the margins of many pages are short apps—application dialogues: In the News relates a page’s content to today’s news; Evolution points to evolutionary connections; and Biology & You explains how the page’s content is linked to something in a student’s everyday life. These short essays do not attempt to teach the content of the page, but rather to relate it to something the student knows or cares about. There are several apps in every chapter, some of them surprising, all of them interesting.

A third way this new edition links what the student is learning to everyday life are the Implication questions found below key illustrations in each chapter. These questions are not directed at assessing the student’s understanding of the illustration, but rather push the student to think about the implications of the illustration to their own lives. Many are open-ended, probing a student’s own opinions on a subject. All of them link the illustration to the student’s everyday life.

Using Visuals to Teach Concepts

Art has always been a core component of this text, as today’s students are visual learners. To help students learn, Essentials of The Living World has a clean and simple art style that focuses on concepts and minimizes detail. In this edition I have sought to amplify the power of illustrations to teach concepts by linking the interior content of illustrations directly to the text that describes that part of the illustration. I have set about doing this in three ways: 1. Bubble numbers. In complex diagrams where there is a lot going on, I have placed numbers (set off in colored balls) at key positions, and the same “bubble numbers” at those locations in the text where that element of the illustration is being described. This makes it much easier for a student to use the illustration as it was intended, to walk through the process and see how the parts are related. 2. Integration of art into text. In some places like the introduction to photosynthesis (treated on pages 100 to 103) many different processes are covered, each with its own illustration. In these instances, bouncing back and forth between illustration and text makes it difficult for a student to gain or retain perspective, and so I have chosen in these instances to integrate the illustrations directly into the text, providing a single narrative. 3. Phylum facts. The biggest problem students encounter in studying animal diversity is the mass of detail filling every page. To ease the student’s task of sorting through all this, I have constructed “Phylum Facts” illustrations that highlight the key points.

In setting out to improve this edition of Essentials of The Living World, my focus has been on improving it as a learning tool. I have made many changes, some obvious, others more subtle, all of them aimed at making it easier for students using this text to understand and appreciate what they learn in lecture, and so do better in the course.