The Tangled Bank: An Introduction to Evolution

Citation

Zimmer, C. (2013). The Tangled Bank: An Introduction to Evolution (2nd ed.). Roberts and Company Publishers.

Chapter Summary

The second edition (published August 2013, copyright 2014, about 470 pages) has fifteen chapters and, according to the publisher, 285 drawings and photographs. Its publisher, now Macmillan Learning, presents it as the first textbook about evolution written for the general reader and notes its wide use in non-majors biology classes. The second edition was, in the publisher's words, dramatically revised: it adds an entirely new chapter on human evolution, further concepts, new illustrations and new research, and a separate study guide by Alison Perkins. Reviews of the first edition (2010) describe the method that the second keeps: each chapter opens with a scene of researchers at work, which becomes a case study developed later in the chapter, and the writing avoids equations.

Chapter 1: Walking Whales: An Introduction To Evolution

The opening chapter uses the evolution of whales, beginning with fossil whales with legs, to introduce what evolution is and what kinds of evidence biologists use. In the first edition the chapter ended with a case study of why whales have blowholes that drew on fossils, anatomy, genetics, life history and conservation.

Chapter 2: Before and After Darwin: A Brief History of Evolutionary Biology

A history of evolutionary thought from natural philosophy to Darwin and the idea of natural selection, setting up the concepts the rest of the book develops.

Chapters 3–4: What the Rocks Say; The Tree of Life

Chapter 3 explains how geology and paleontology reveal the history of life. Randy Moore, reviewing the first edition in CBE—Life Sciences Education, singled out its account of how the ages of rocks and fossils are established, built on the work of Steno, Hutton, Lyell, Cuvier and William Smith, as the best he had seen in an introductory biology book. Chapter 4 shows how biologists use phylogeny to reconstruct the deep past.

Chapters 5–7: Evolution's Raw Materials; The Ways of Change: Drift, and Selection; Molecular Evolution: The History in Our Genes

The genetic core of the book. Chapter 5 covers heredity and mutation, the raw materials of evolution; Chapter 6 covers genetic drift and natural selection; Chapter 7 shows how genes record evolutionary history. In the first edition Greg Bole (Evolutionary Applications) praised the way the drift-and-selection chapter conveyed most of the Hardy–Weinberg model through percentages and genotypes rather than algebra, using analogies such as drawing coloured jellybeans, alongside graphs from computer simulations.

Chapters 8–9: Adaptation: The Birth of the New; Sex and Family

Chapter 8 explains how new adaptations arise; in the first edition it contained a box on "How Not to Study Evolution", the book's one extended comment on creationist arguments. Chapter 9 treats sex and family; in the first edition the corresponding material included sexual selection.

Chapters 10–11: Darwin's First Question: The Origin of Species; Macroevolution: Life Over the Long Run

Chapter 10 deals with speciation. Chapter 11 moves to large-scale patterns over long periods of time; the first edition's equivalent chapter dealt with radiations and extinctions.

Chapters 12–13: Intimate Partnerships: How Species Adapt to Each Other; Minds and Microbes: The Evolution of Behavior

Chapter 12 covers coevolution and symbiosis between species. Chapter 13 treats the evolution of behaviour.

Chapter 14: A New Kind Of Ape

The chapter on human evolution that the second edition added. In the first edition human evolution was woven through the other chapters instead; Moore noted that some readers would like this and others would not, and Bole found it made the topic hard to assign for a specific lecture.

Chapter 15: Evolutionary Medicine

The book ends with evolution applied to health. The publisher points to the fight against antibiotic-resistant bacteria and the analysis of the human genome as examples of evolution's relevance.

Key Concepts

Chapters 1–4: evidence and history

• Evolution and its evidence: change in populations over generations, shown through fossils, anatomy and genes, introduced with whales.
• Natural selection: Darwin's mechanism, presented in its historical setting.
• Dating rocks and fossils: how geologists and paleontologists establish the age of the Earth and the timing of the history of life.
• Phylogeny: the tree of relationships among species, reconstructed from shared characters.

Chapters 5–9: mechanisms

• Mutation and heredity: the raw materials on which evolution acts.
• Genetic drift and selection: random and non-random change in allele frequencies, introduced without equations.
• Molecular evolution: change in DNA sequences used to reconstruct history.
• Adaptation: the origin of new traits.
• Sexual selection: evolution driven by mating competition and choice.

Chapters 10–15: patterns and applications

• Speciation: the origin of new species.
• Macroevolution: long-term patterns such as radiations and extinctions.
• Coevolution: species adapting to each other, including intimate partnerships.
• Human evolution: the origin of our own species.
• Evolutionary medicine: applying evolution to resistance and disease.

Critical Analysis

Strengths

• Exceptional readability and illustration. Reviews of the first edition agree on this. Moore called the book well produced, up to date, readable and exceptionally well illustrated; Bole praised its clarity and narrative, and the publisher cites a CHOICE review (B. K. Hall) calling it astoundingly well illustrated. The second edition has 285 drawings and photographs.
• Science shown in action. Each chapter begins with research in the field (fossil hunting, tracking venomous snakes, gathering DNA), and the story is resolved later in the chapter, so readers see how evolutionary hypotheses are tested rather than only what is known.
• Explains how we know. Moore singled out Chapter 3's explanation of how rocks and fossils are dated; Bole highlighted treatments such as the FOXP2 gene and the evolution of the vertebrate eye. The book presents evidence rather than arguing against creationism point by point.
• Revised in response to its first edition. The second edition adds the separate human-evolution chapter whose absence both reviewers had remarked on, and a separate study guide supplies study aids and activities.

Limitations

• Light on pedagogy within the book. Both first-edition reviewers noted that chapters end with summaries but no questions, focus questions or other self-test material, and Bole thought non-majors might struggle to build a mental map of the discipline. The second edition's study aids are in a separate study guide.
• Not a majors' text in evolutionary genetics. Bole judged the book insufficient on its own for a second- or third-year majors' course because of its limited treatment of evolutionary genetics; it suits majors as a companion or source of examples.
• Dating of examples. The book's appeal lies partly in its recent research stories; the second edition dates from 2013, and newer discoveries, especially in human evolution and genomics, need other sources.

Where It Fits in the Course

In the evolution course list, The Tangled Bank is the introductory book for readers who want breadth, examples and pictures. Brian and Deborah Charlesworth's Evolution: A Very Short Introduction covers mechanisms and evidence in about 160 pages; read it first for a compact framework, or after Zimmer to consolidate. Darwin's On the Origin of Species pairs well with Chapter 2's history.

For majors, Zimmer is a companion rather than a substitute for a full textbook. Bergstrom and Dugatkin's Evolution presents evolutionary biology as an active, data-driven science, with research case studies; it is the natural next step. Futuyma and Kirkpatrick's Evolution assumes prior biology and genetics and deepens an introductory course, and the Charlesworths' Elements of Evolutionary Genetics is the graduate-level treatment of the population-genetic theory that Zimmer explains without equations in Chapters 5–7.

How to Use This Book

The book is written for non-majors and general readers and assumes no more than school biology. It also suits biology majors in their first year, as preparation for a majors' evolution course, and instructors looking for case studies.

A practical plan:

• Core sequence: Chapters 1–8 in order. Chapter 1 sets up the questions, Chapters 3–4 the evidence and methods, and Chapters 5–7 the mechanisms that everything later relies on.
• Then choose: Chapters 9–13 can be read according to interest (sex and family, speciation, macroevolution, coevolution, behaviour). For a short course, Chapters 9 and 10 are the most important.
• Applied topics: Chapter 14 for human evolution and Chapter 15 for medicine; both draw on the mechanisms of Chapters 5–8.

Because the book itself offers few self-test questions, use the companion study guide, or after each chapter write a short summary of the opening case study and explain how its evidence supports the chapter's conclusions. Students heading towards a biology degree should follow with a full textbook for the quantitative population genetics.