Reviewing a high-school book in biology

An Obsolete Collection
of Myths and Mistakes

Terrence M. Gosliner

The book's 48 chapters are grouped into nine units. The first unit, "Introduction to Biology," sets the tone for all the rest:

Page 17 lists "Branches of Biology": botany, zoology, anatomy and physiology. Then it tells that some of them "are further divided into more specialized areas of study," including cytology, embryology, marine biology, paleontology and exobiology. I do not know why exobiology, the search for extraterrestrial life, is worth listing while evolutionary biology, ecology, ethology and molecular biology are not.

The writers then turn to retelling classic myths. They describe scientific inquiry in terms of a six-phase process in which "the scientist" forms a hypothesis and then conducts an experiment. This is their whole idea of science. But in the same chapter, their list of "Important Biologists" includes Charles Darwin, whose grandest work was based on the observation of nature as he found it, without experimental intervention.

In noting the advent of biochemical studies in taxonomy, the writers offer another myth. A caption on page 45 says: "The horseshoe crab was originally thought to be a true crab. However, biochemical studies of the horseshoe crab's blood revealed that the organism was more closely related to spiders." In fact, the relationship of horseshoe crabs to spiders was established, by morphological studies, at least 100 years ago. The writers give the impression that biochemical work and genomic-sequence studies have revolutionized taxonomy, but that too is a myth. Such studies are furnishing much new information for resolving phylogenetic questions, but they also present some of the same problems that affect traditional methods.

It is not reassuring, however, to see the obsolete, mistaken way in which Prentice Hall's writers conduct their survey. Organisms are grouped into chapters according to convenience rather than phylogenetic relationships. Thus we find a unit that lumps all the invertebrates together, even though the invertebrates are well known to be a paraphyletic group -- a group that includes certain ancestral organisms but excludes some of their descendants (in this case, the vertebrates). Today's taxonomy rejects paraphyletic groups and seeks instead to define assemblages in which each ancestral type is grouped with all forms that have evolved from it. Hence today's taxonomy does not see the invertebrates as a valid group.

Even when Prentice Hall's writers appear to have an inkling about a phylogenetic relationship, they usually ignore it On page 433, for example, they mention that larval annelids resemble larval mollusks. Despite this, they discuss annelids in chapter 26, lumping them with various other "worms," and they put mollusks in chapter 27, lumping them with echinoderms. This can easily produce, in the minds of students, false impressions about relationships.

Taxonomy based on evolutionary relationships may have eluded the writers because their own ideas about evolution are inaccurate. Page 209, in a passage about evolution by natural selection, says that poorly adapted organisms die before they can reproduce. While this may occur in some extreme situations, differences in Darwinian fitness are most commonly expressed as differential reproductive success -- not as the all-or-nothing result that the writers imagine. The picture on page 209 shows a short-necked giraffe dying while its longer-necked relatives feed contentedly on succulent leaves. That is a stretch, both literally and figuratively.

One of the book's more laudable aspects is its array of "Career" features -- half-page vignettes which try to describe jobs that are related, in some way, to biology. But the vignettes that deal with scientific work lack any hint of the excitement and the sense of discovery that have drawn most biologists into their chosen fields. The "Career" item on page 48, for example, says this about the work of museum technicians: "Technicians clean and preserve animal and plant specimens and carefully mount and arrange them in glass cases." Contrast that with the things that museum technicians really do, such as participating in field research, discovering new species, and developing computer systems that process and store information about specimens.

Page 20 has a "Career" feature about biology teachers. It depicts them as people who make lesson plans, who implement curricula dictated by school-district headquarters, and who have conferences with parents. Advertising like that may help to explain the shortage of inspired, inspiring teachers.

On page 140, in a sketch of the career of a "science editor," we read that the production of a textbook may require three years. In the case of Prentice-Hall Biology, this amount of time was clearly insufficient.

On page 243 the writers briefly mention AIDS. They say that something called AIDS "has reached epidemic proportions" and that there will probably be 365,000 cases in the United States by 1992. But they never tell what AIDS is, never tell that it is fatal, and never say anything about transmission or prevention. They just fill half a page with evasive chatter about T cells and macrophages. Their prudish approach may help to sell books in backward school districts, but it may also cost some students their lives. Even Ronald Reagan's conservative surgeon general, C. Everett Koop, knew that sound education had to take precedence over puritanical taboos.

The growth of the human population is mentioned on page 750. The writers tell us that human numbers may be approaching Earth's carrying capacity, and then they casually suggest that this situation can be managed by new "technologies," medical practices, sources of food, and kinds of housing. For how much longer will schoolbooks try to perpetuate that myth? Nowhere does Prentice Hall's book tell of the need to practice birth control and to curtail population growth.

To its credit, the book tries to portray ethnic and cultural diversity' in its pictures of biologists at work. I do not know, however, why it portrays Cro-Magnon man (on page 229) as a clean-shaven, northern European male who looks like Thomas Jefferson or Neil Young.

As a scientist, I find this book's many errors and distortions to be highly objectionable. As a parent of two children who will attend high school during the book's commercial lifetime, I find the omissions and the lack of information to be even more alarming. Certainly the writers of biology textbooks can be expected to do better.

Some Creative Claims
About an Absurd Book

William J. Bennetta

Prentice Hall's new catalogue states that the 1990 version of Prentice-Hall Biology "is organized around the classification of life forms." It fails to tell, however, that the book "classifies" organisms in an archaic and sometimes capricious way, giving little attention to the classification techniques used by biologists.

The catalogue also says that the book offers a "comprehensive coverage of biology concepts" that is "organized around a phylogenetic approach." But when the book itself is examined, that claim collapses.

Phylogeny -- the evolutionary origins and histories of groups of organisms, and the evolutionary relations among groups -- is not used an organizing theme at all. It is conspicuous chiefly by its absence, because Prentice Hall's writers routinely ignore chances to give crucial phylogenetic information. Sister-group relations? The writers seem unaware of them. Unity of the eukaryotes? I see nothing about this. Deuterostomes versus protostomes? No. Phylogeny of arthropods? No. Phylogeny of fishes? I find nothing about this much-studied subject.

Phylogeny of the reptiles? Yes. The book's treatment of reptiles, including the origin of birds, does acknowledge phylogeny, though it is not "organized around a phylogenetic approach." In fact, the writers quickly ruin their chapter about birds by saying that those animals comprise four major groups: perching birds, water birds, birds of prey and flightless birds. That is amateurish and fanciful. It has no phylogenetic basis or taxonomic meaning. Are penguins "water birds" or "flightless birds"? Are ospreys "water birds" or "birds of prey"?

Neither phylogeny nor phylogenetic is in the book's index or glossary.

Do you look at book covers?

The 1990 version of Prentice-Hall Biology has a front cover bearing the words "Revised Fifth Edition," and the book's spine displays the same label. When I saw this, I wondered: Did the book differ substantially from the preceding version, dated in 1987?

Guided by a list of random numbers, I sampled 75 pairs of like-numbered pages from both versions. In every case, I found that the page in the 1990 version and the page in the 1987 version were identical: picture for picture, word for word, comma for comma. According to my sample, the new version had nothing new whatsoever. Later, however, I saw trivial alterations on pages 44,45 and 243. As far as I know, those tiny tinkerings (plus the amended copyright page, with its new date and its new ISBN code) may constitute all the revising that produced the "Revised Fifth Edition."

I hope that you will not believe what Prentice-Hall Biology says, for it is full of misconceptions, mistakes and misnomers. Two especially significant cases show that this book was assembled by people who had not done much serious studying of biology. One case involves the writers' queer notion of science. The other involves their mishandling of biological nomenclature.

Biology is usually taught in grade 10, and it is the last science course that many students take. For them, it is the last chance to learn what science is, how it differs from other endeavors, and how scientists work. These are important matters -- perhaps more important than anything else that a biology text might address. Prentice-Hall Biology dismisses the nature and processes of science in a vapid, cosmetic passage that starts on page 17, has but ten paragraphs and is quite misleading. Science, it says, goes like this: "The scientist" forms a tentative statement, or hypothesis, about some aspect of nature -- then, "to determine whether the hypothesis is correct, the scientist devises an experiment to test the effect of only one factor."

Rubbish. There are whole realms of science -- e.g., astronomy, meteorology, paleontology and oceanography -- in which the role of experiment is minor at best, and in which most information comes from observations in non-experimental settings. In biology, this is true of such fields as biogeography, ecology and taxonomy.

Science is a well defined enterprise that seeks to explain nature by enlisting only two things: evidence and reason. This is the vital point that distinguishes science from other approaches to nature, such as magic, folklore, folk medicine and religion. Prentice Hall's writers apparently have not noticed this. Their ten-paragraph fantasy does not even mention the words evidence and reason, much less explaining what those words mean. (They do use the expression observations, but in a misleading way: "Observations," in Prentice-Hall Biology, explicitly and necessarily come from experiments. This just reinforces the notion that all science follows a simple-minded recipe for performing manipulations in laboratories.)

In the end, perhaps the most striking feature of Prentice-Hall Biology is that the writers do not know how to represent the scientific names of organisms or groups of organisms. They do not know that names of species or genera demand italic type, but names of other taxonomic entities -- families, orders, classes, and so on -- do not.

Because the writers are unfamiliar with this rule, their book teems with ludicrous mistakes: Not only in their text but even in their index, they italicize nearly every name that comes by, creating such bastards as "the phylum Chordata" and "the class Crustacea" and "the order Cetacea."

This anomaly is not intrinsically important: Students' perceptions of living things will not be greatly affected by inappropriate typography. Its significance lies in what it tells about the writers. Their acquaintance with biology, and with the literature of biology, must be extremely weak.

A fine array but an absurd book.

Terrence M. Gosliner is a zoologist, a specialist in the biology of marine invertebrates, and a staff scientist at the California Academy of Sciences, in San Francisco.

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.