A Note from the Authors of
THE CARTOON GUIDE TO BIOLOGY
In recent years, educators and research biologists have agreed that introductory biology courses should focus more on core concepts and less on all the nitty-gritty details. For example, AP Biology courses now are organized around four Big Ideas (Evolution, Cellular Processes, Genetics and Information Transfer, and Interactions). In Vision and Change, a treatise on undergraduate biology education, the authors similarly urged educators to focus on a few Core Concepts (Evolution, Structure and Function, Information Flow, Transformations of Energy and Matter, and Systems). The Cartoon Guide to Biology also urges educators to emphasize the interdisciplinary nature of biology and the relationship between biology and society. We agree with this strategy and have written (and drawn!) our book with these recommendations as guiding principles.
The Cartoon Guide to Biology is a rigorous, conceptually integrated, and graphic overview of first-year biology. It uses visual explanations to clarify concepts, illustrate relationships, and display sequences of events.
Most introductory biology courses today begin with the cell. Teaching biology, therefore, typically works from the “inside out,” from the invisible to the visible. The Cartoon Guide to Biology necessarily follows the same course but prefaces its sections on chemistry and the cell with an extensive chapter explaining why this approach is appropriate and necessary. We start with the visible to motivate the reader and to explain that the invisible is the foundation of conceptual understanding.
Our informal cartoon drawings have several advantages over textbook-style illustrations. Cartoons bring greater personality—but also greater realism—to the biological world. Amino acid structure becomes clearer. Proteins really look and act like proteins. Attraction and repulsion become more, well, human and intuitive.
We believe that this anthropomorphism is a good thing pedagogically if properly used. Endowing microscopic structures and creatures with human-like responses unquestionably helps students identify with, understand, and retain the material. Attraction, repulsion, signaling, excitation, and relaxation are universal phenomena. The only proviso is: never imply intention or planning. Nowhere in the book is there any drawing that suggests intention, forethought, or design on the part of our wriggling, interacting cast of characters. In our view, this is entirely proper.
An overview of our topics and treatment:
The Cell. Our visual account of the cell is particularly lively and helps distinguish clearly between passive and active processes. The plasma membrane is thoroughly explored, and we provide examples of intracellular activities, like glycogen synthesis and myosin action. We show that a cell is a dynamic place.
Energy. We offer many easily grasped examples, from fire to mousetraps. We discuss free energy, activation energy, the role of enzymes, ex- and endergonic reactions, and reaction coupling. We show how the energetics of chemical reactions are akin to uses of energy we see in our daily lives.
Respiration. Various visual tricks are deployed to clarify various processes. In particular, the various stages of cellular respiration look very different from one another. There is no question where the Krebs cycle ends and ATP synthase springs into action.
Photosynthesis. Here, too, characters make the story. We lay unusual stress on the role of RuBisCo, because doing so emphasizes its role in the carbon cycle to be discussed later (plus it’s such a weird enzyme!). Photosynthesis is described in the context of fixing the inorganic carbon generated by respiration. We also try to emphasize that plant mass, not just plant energy, comes from photosynthesis. For some reason, students often miss the fact that “plants eat air.”
Communication. This innovative chapter, inspired by recently issued teaching guidelines emphasizing the interconnectedness of biological topics, shows communication at all biological levels, from chemicals to systems, and demonstrates how they all depend fundamentally on protein allostery. This chapter also lays the foundation for gene regulation.
The Genetic Code. Although gene expression is a more challenging subject than DNA replication, we address it first because it builds directly on the preceding material. Having said so much about proteins, we feel it is more natural to put protein synthesis here.
Gene Regulation. A natural progression from the previous two chapters, and full of obvious visual and cartoon possibilities. Readers of The Cartoon Guide to Genetics will have some sense of what to expect.
Multicellularity. Here we show how the regulation of genes can cause cells to differentiate into different cell types to make tissues, organs, and organ systems. We display many different views of blood vessels, the heart, the lungs, intestines, and liver, then discuss the general problem of systemic regulation vs. cell self-interest.
DNA Replication and Mitosis. Having dealt with gene expression beforehand, we are now free to use DNA replication, mitosis, and mutations to introduce the organically related sequence of topics in the rest of the book: sex, evolution, and systems.
Meiosis and Sex. This includes an account of Mendel and Mendelian genetics. Mendel, of course, becomes a character, highlighting the medium’s capacity to move back and forth between depicting biology and biologists.
Evolution. We describe the rise of evolutionary thinking and its reception. Sequences and diagrams explain artificial, natural, and sexual selection, coevolution, and changes in gene frequency, using the speckled moth as an especially clearly seen example.
Classification and Phylogeny. Among other things, this chapter explains biology’s strange fascination for Latin names, and answers the question everyone wants to know: is a giant panda a bear or a raccoon?
Interdependence. This chapter shows interdependencies at microscopic and macroscopic levels. We offer both illustrations of ecosystems (including a perspective drawing of a biofilm) and diagrams of chemical cycles.
Disruption. Appropriately enough for the times we live in, the book concludes with a discussion of how organisms and systems respond to stress. Up to now, life’s ability to preserve homeostasis under stress has been emphasized, but now we turn to stresses that threaten the survival of organisms and ecosystems. (What’s a book about life without some discussion of death?) We discuss system resilience, predator-prey relationships, and some challenges presented by our super-successful species: chemical pollution, deforestation, monoculture, fossil fuel use, global warming, desertification, and eutrophication. We conclude with some examples of successful ecosystem recovery and, again shifting from biology to biologists, we describe the roles that biologists will play in efforts to ameliorate or reverse the damage.
Professor of Biology, Davidson College