Reviewing a high-school book in biology

This Biology Book
Is One of the Best

Lawrence Davis

That said, Biology: Visualizing Life still has room for improvement.

In reviewing a biology book, there are two related issues that must be considered:

First, does the book offer an accurate portrayal of biology, as seen by a significant fraction of today's biologists? For Visualizing Life, the answer is yes.

Second, does the book achieve the aims that it sets for itself? Some of the aims of Visualizing Life are put forth in a preface signed by George B. Johnson, the Washington University professor who is the first of two authors listed on the book's title page. In his preface, Johnson tells us that "The heart of biology is a set of simple ideas that explain why things work the way they do and how they got that way." I am not sure that the ideas are simple, but the focus on understanding ideas is a right one. I would be pleased if any of my graduate students knew and understood all of the ideas that Visualizing Life conveys.

Johnson further distinguishes "ideas" from "information," and he states an intention to focus on "ideas." But ideas really have a high information content, and the information is highly organized. I assume that what Johnson actually means is that he wants to de- emphasize the accumulation of isolated facts and statistics. Good.

Visualizing Life has at least one illustration on every page, and the illustrations, in general, are of high quality and are pertinent to the topics discussed in the text. The book has less text than Holt's Modern Biology does, although the number of pages is about the same in both. A typical page in Modern Biology has some 2,700 characters while a typical page in Visualizing Life has fewer than 2,400. The pages in Visualizing Life are larger, and the margins narrower, providing more room for pictures.

The readability is high, and most of the writing depends on short declarative sentences. Yet the conceptual content is also high, as when the text describes the coevolution of symbiotic pairs of species (pages 270 and 271). Visualizing Life should work well for advanced students and, if the book is used with care, for students whose abilities are average or even lower. However, some students may find it hard to see the scientific forest through the pictorial trees.

Visualizing Life contains 34 chapters, grouped into six units. Unit 1 is really an introduction to biochemistry and cell biology, under the title "Study of Life." Unit 2, "Continuity of Life," covers genetics, evolution and life's origin. Unit 3 has three chapters on "The Environment." Unit 4, "Diversity of Life," is a fairly traditional survey of life forms. Unit 5 is devoted to the "Animal Kingdom." Finally, Unit 6 has eight chapters, arranged mainly by organ systems, dealing with "Human Life." This sequence is typical of good college-level biology text.

Within each unit, every chapter ends with a "Highlights" page, a "Review" spread, and then an "Investigation" activity. The "Review" spreads -- especially their lists of multiple-choice questions -- don't seem to reflect the goal of focusing on ideas, for ideas rarely come in multiple-choice versions. The greatest potential for improving this book lies in improving the "Review" questions. The "Investigation" activities are of variable quality: Some seem very good, but others are too complex for average students, even in college. Dissecting a chicken wing (page 636) is good. Measuring diffusion by looking for the action of amylase on starch (page 86) is too complex.

Visualizing Life contains feature articles of several kinds: "Discoveries in Science," "Science, Technology and Society," "Journeys" and "Science in Action." A "Journeys" feature usually consists of a large painting of an organism, with notes about the organism's anatomy and natural history. The eighteen "Science in Action" items fall into two categories: Nine of them consider scientific topics, such as cystic fibrosis or sexual selection, while the others are inspirational profiles of persons whose occupations are somehow related to biology.

Holt has found some very good illustrations for Visualizing Life, particularly the depictions of cell membranes. The art of biomedical illustration has been honed to a very sharp edge. When publishers take advantage of available skills, they can get excellent results.

Unfortunately, however, Holt's editors and illustrators have sometimes fallen down. On page 36, for example, a helix is shown as a sinusoidal ribbon. That suggests that someone did a poor job of copying a rather poor drawing that appears in the BSCS text Biological Science: A Molecular Approach.

Another example: On page 661, in chapter 28, the illustration of the human eye is weak, conveying the notion that light rays converge in front of the eye and diverge inside it. The illustration is completely unlabeled, and the adjacent text says only that light "is focused by the lens" and that the lens "changes shape." In the same chapter, the "Investigation" invites the student to fuse a picture of a tiger with a picture of a cage by using binocular vision, but the pictures are misaligned -- when the two images are fused, the tiger's feet are lower than the cage's wheels. That's just dumb.

The lesson here, as usual, is that text and illustrations must support one another. They cannot be independent events that simply happen to occur on the same page. If we are to visualize life, we need to see it as it really is.

Besides trying to focus on ideas, Visualizing Life has another declared aim. It seeks to present biology in a way that revolves around six themes: energy and life; scale and structure; stability; evolution; patterns of change; interacting systems. These phrases, listed on pages 16 through 18, are obviously clichés, heavily loaded with multiple implicit meanings. They do not really say much by themselves, unless one knows about the debate that generated them: They emerged from the State of California's recent effort to define a science curriculum [note 2].

Are the themes really reflected in the body of the book? The theme of evolution certainly is. Evolution by natural selection is very well integrated into many chapters, and an evolutionary thread runs through the whole text. This is a key feature and probably the book's strongest aspect, because it reflects where biology is today. At last, Holt's writers have done away with the Lamarckian straw man. Similarly, there is no nonsense suggesting that creationism may be science rather than religion.

The phrase patterns of change, as it is used in this book, means cellular differentiation: Our fate lies not in our stars but in our cells. (True, but how could it lie anywhere else?) The theme energy and life figures in all the chapters about cells, as well as in the units about ecosystems and about the human body, but we would expect this in any book -- there is no other way. The idea of interacting systems is evident in the book's treatment of ecosystem dynamics, stability turns up (appropriately) in the discussion of homeostasis, and the scale and structure theme is illustrated at many levels, from the structure of a carbon atom to the challenge posed by the population explosion.

So it seems that the text really does incorporate the announced themes, in one way or another. If Holt can get a competent person to review the text and the illustrations together, and another competent person to improve the test questions on the "Review" spreads, the next version of this good book can be even better.

Right for Some Students,
but Not Right for Others

William J. Bennetta

USA Today is still going strong, and the idea of making publications look like television shows has turned up in various other quarters. It surely has become prominent in the schoolbook business, but with generally unimpressive results. A typical TV textbook (e.g., Merrill's Biology: The Dynamics of Life) is a brainless mess -- bits of silly, old material floating in a sea of new glitz.

Holt's Biology: Visualizing Life is different. It's a TV textbook, to be sure, ruled by garish design and by a plethora of pictures, many of them oversized, weirdly shaped or weirdly placed. The text has been chopped and squeezed, to make it fit into the space that remained after the pictures had been accommodated, and this approach has plainly imposed constraints on the amount of information that the text can convey. But within those constraints, Visualizing Life presents biology in a way that is innovative, generally accurate and usually up-to-date. While the content sometimes seems shallow and too typological, the writing is skillful, and most of the illustrations strike me as competent and useful.

In my judgment, Visualizing Life is the best high-school biology book available for use by students who don't intend to pursue higher education in science or to seek scientific careers. I would not, though, recommend this book for students who intend to become science majors in college. Those students need more information than Visualizing Life can give them, they need to go beyond the typological view of nature that Visualizing Life favors, and they need practice in reading, not in looking at television.

Here is another bit of innovative thinking in Visualizing Life: In the chapter titled "The Fragile Earth" the text tells that trees are renewable, but it does not repeat the traditional, nonsensical claim that forests are renewable. In the next edition, the Holt writers can do even better: They can tell explicitly that forests are not renewable, and that tree farms are not forests. The student who understands those two points will be able to see through the deceitful propaganda dispensed by timber companies.

The unit about human biology in Visualizing Life, like the corresponding units in Holt's other biology books, is really just a weak survey of human anatomy and physiology. Even so, it has something to praise: In Visualizing Life, the chapter on "Reproduction and Development" acknowledges contraception and says a little about condoms, vasectomies, diaphragms and spermicides. Good! This book has taken a step toward describing reality. It still has a long way to go, however, for it fails to examine breeding in any societal context, fails to relate breeding to matters of public health, and fails to explain how some of our country's social and economic systems are breaking under the weight of overpopulation.

The topic of global overpopulation appears in the chapter on "The Fragile Earth," but it is treated in a vague, timid and misleading way. In this case, the Holt writers [note 3] have not escaped the influence of traditional foolishness. They make an unexplained allusion to undescribed population-control programs in unspecified "countries," and they mention a prediction that the population of the world may stabilize, by the end of the next century, at some 13 to 15 billion people. Then they glibly say:

No one knows whether the world can support 13 to 15 billion people indefinitely. Finding a way to do so is the greatest task we will face in the coming years.

That airy-fairy stuff will not do, and the "No one knows" statement is absurd. First, the statement falsely implies that the question of how many people the world can support is entirely beyond our ken. Second, it ignores this crucial truth: The question of how many people the world can sustain is inseparable from the question of how those people will live.

If we accept the prospect that evidently delights some religious zanies -- the prospect of a devastated planet packed with people who live like cattle on a feedlot -- then the maximum sustainable population may be even greater than 15 billion. But what if we posit a world in which all people would have social, material and environmental amenities comparable to those enjoyed by the middle class in the United States during the 1950s? If we choose that standard, we discover that Earth would not even be able to sustain the number of people that it has right now.

Holt's writers are oblivious to all this, and they do not suggest what life on Earth would be like if the population reached 15 billion. Instead, they depict the sustaining of 15 billion people as a sort of goal, and they give us the "task" of "finding a way" to achieve it. Bah!

Unless students get sound information about population issues, they can hardly be expected to develop responsible attitudes toward breeding, and they will have little hope of understanding the ecological catastrophes, economic dislocations, mass migrations, and resource wars that will become increasingly frequent as the 21st century unfolds. Holt's writers can greatly improve Visualizing Life, in its next edition, by providing the information that students need.

I have one more suggestion for making Visualizing Life better: The Holt staff should dump those cheesy biographies that appear under the rubric "Science in Action." They are funny, in a way, for they recall a well known series of advertisements used by the distributors of Dewar's Blended Scotch Whisky. What matters much more, however, is that the biographies are so obviously contrived and disingenuous that they are insulting.

Editor's notes

1. Holt's other biology textbooks are Modern Biology (which Lawrence Davis reviewed in The Textbook Letter for July-August 1992) and Biology Today (which Davis reviewed in The Textbook Letter for March-April 1993). [return to text]

2. See the two-part article "California's New Framework Demands New Science Texts" in The Textbook Letter for November-December 1990 and January-February 1991. [return to text]

3. The title page of Visualizing Life lists two authors -- George B. Johnson and Gary J. Brusca -- but the preface is called a "A Message From the Author" and is signed by Johnson only. I wonder what Holt's editors were trying to gain by creating that contradiction. In the preface, Johnson presents himself as the one and only person who wrote the book, and he says nothing to suggest that he ever has heard of Gary J. Brusca. [return to text]

Lawrence Davis is a professor in the Department of Biochemistry at Kansas State University (Manhattan, Kansas). His scientific interests include biological nitrogen fixation and the application of plants to the bioremediation of soils. He has taught plant genetics and plant physiology to high-school teachers for many years.

William J. Bennetta is a professional editor, a fellow of the California Academy of Sciences, the president of The Textbook League, and the editor of The Textbook Letter. He writes often about the propagation of quackery, false "science" and false "history" in schoolbooks.

Addendum

Holt issued another version of Biology: Visualizing Life in 1998. A review of the 1998 version appeared in The Textbook Letter for September-October 1997.

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