Let's start by reviewing some history. During the 1970s and 1980s, most of the high-school biology texts and middle-school life-science texts printed in this country offered a mangled form of "biology" that reflected decades of pressure from certain religious fundamentalist groups. Some publishers - for example, Addison-Wesley, DC Heath and Company, the Macmillan Publishing Company, and Holt, Rinehart and Winston - issued books that concealed the fact that modern biology is a coherent science unified by the central concept of organic evolution. The books said nothing of evolution or the history of life on Earth, or they buried those topics under mounds of details. If one looked for certain terms or concepts in evolution, they could often be found in glossaries, or "mentioned" in the text; so the publishers could claim that the topics were "covered". However, they gave no sense of the importance of evolution, and the entire topic could be easily avoided. This was convenient for school districts that preferred not to treat evolution, and for publishers that preferred not to publish alternate editions of the same coursebook.
In many cases, the schoolbook-writers went out of their way to teach students that scientific statements about the history of life were nothing more than speculations. For example, Heath Life Science (1984) depicted the ancient dinosaurs as mere figments in which "some scientists believe", and Scott, Foresman Life Science (1987) taught that no one knew whether ichthyosaurs and pterosaurs had really existed.
Some writers made vague allusions to evolution while replacing the word evolution with false synonyms, such as "development" (a completely different biological discipline) or "natural selection" (a mechanism of evolution) or even "environmental change" (which one normally associates with weather and climate). Others mentioned evolution by name, but they presented it as an eccentric "theory" left over from the 19th century which had no modern significance. They also taught that the word theory merely meant a belief, and they urged students to learn about "other theories" pertaining to the origins of organisms. The phrase "other theories" was, of course, a code-word for Bible stories. This led directly to the "two-model" approach of creation and evolution advanced in school districts by many creationists of the 1970s and 1980s.
Other school-book authors - such as certain contributors to Laidlaw's Experiences in Biology (1981) or Holt, Rinehart and Winston's Holt Science series (1986) - went even further. They rejected evolution entirely. They didn't mention the word, they didn't refer to the concept, and so they effectively excluded the biology of the 20th century.
In the late 1980s, however, the major schoolbook-publishers sensed a demand for biology textbooks and life-science textbooks that would present some real science. Since then, they have undertaken - with greater or lesser success - to produce lots of new books that include conspicuous passages about evolution and the evolutionary histories of important lineages. Some of today's biology books even tell students explicitly that evolution is biology's central organizing concept.
Against that background let us consider the situation that prevails today. It has three major aspects:
1. evolutionary content
2. contemporary evolutionary concepts
3. resistance to evolutionary ideas.
Evolutionary ContentIf we look at the content of current books, we see that creationist influence has almost disappeared. Exceptions occur in Addison-Wesley Biology and the two Science Probe books issued by South-Western Educational Publishing. I described the case of Addison-Wesley Biology in The Textbook Letter, January-February 1997:
There are scientific theories, and there are "other theories". Scientific theories are explanatory principles that have been tested and confirmed. Each scientific theory is a structure of ideas, confirmed by preponderant evidence.... [It] explains a body of observations and thus explains some aspect of nature.In the Science Probe books: the writers do not acknowledge any modern interpretation of the fossil record or any genealogical connections among the organisms of different periods. One could easily gain the impression that each period's "characteristic collection of life forms" originated de novo. You may find interesting the reviews on The Textbook League's Web site.
The "other theories" are Bible stories. The expression "other theories" is one of the [euphemisms] that creationists employ when they try to promote the teaching of biblical myths in science classes. They use it in lines like these: "If students learn about the evolution theory, they have to learn about other theories too," or "If schools don't teach other theories about the universe, they shouldn't teach any theories at all."
...Addison-Wesley Biology [is] a book that Addison-Wesley sells for use in high schools. In both the original version (1994) and the later version (1996), evolutionary biology is introduced in chapter 13. And in both versions, the material at the end of chapter 13 includes this "portfolio" exercise:There are opponents to the scientific theory of evolution. Conduct library research on the various beliefs and on the evidence for other theories about the origin of life.For sheer frugality, that's hard to beat. In a single short item, doubtless based on some creationist handout, the Addison-Wesley writers have done 3 of the creationists' favorite routines. They have conflated theories with mere "beliefs", as if those were equivalent. They have promoted one of the creationists' baffle-phrases - "other theories". And in keeping with the creationists' established practice, they have falsely equated "evolution" with "the origin of life".
At this point, the Addison-Wesley Biology and the Science Probe books are exceptions. The rule nowadays is that high-school biology books and middle-school life-science books are full of references to evolution, often accompanied by phylogenetic diagrams and other illustrations that purport to reflect information about evolution.
Contemporary Evolutionary ConceptsThese books contain information about evolution - so far, so good. But the evolutionary "information" that the books provide is often bogus. It has been hurriedly cobbled together by writers who don't understand what they are trying to write about, and it is often erroneous, incomprehensible, and self-contradictory.
Some of the books are utterly bizarre: They are full of alleged "information" about evolution, yet they resolutely cling to the old practice of viewing the living world in terms of the pre-Darwinian, metaphysical notion of "nature's ladder". The writers are confused about basic concepts such as homology, convergence, and common ancestry. They know little about the physiology and metabolism of living organisms or about their evolution, so they often guess, and guess incorrectly. They think that all scientific methods are experimental, and that the history of life is a ladder toward increasing perfection.
Resistance to Evolutionary IdeasRegardless of whether the information is right or wrong, books loaded with information about evolution pose a real problem for state agencies or local school boards that are controlled by creationists. So the creationists have counterattacked with ... stickers! That's right - stickers that are pasted into schoolbooks to tell the students that evolution is just a flimsy "theory" and that it shouldn't be taken seriously. An example is Alabama's disclaimer:
"This textbook discusses evolution, a controversial theory some scientists present as a scientific explanation for the origin of living things, such as plants, animals and humans.
"No one was present when life first appeared on earth. Therefore, any statement about life's origins should be considered as theory, not fact.
"The word "evolution" may refer to many types of change. Evolution describes changes that occur within a species. (White moths, for example, may "evolve" into gray moths.) This process is microevolution, which can be observed and described as fact. Evolution may also refer to the change of one living thing to another, such as reptiles into birds. This process, called macroevolution, has never been observed and should be considered a theory. Evolution also refers to the unproven belief that random, undirected forces produced a world of living things."