Some Suggestions for Improving Biology Textbooks

Well, they're not my suggestions, they're David Hillis' But they are still pretty good.... In the June 2007 issue of Evolution, Hillis writes about how to make general biology textbooks discuss evolution better. He has a list of ten suggestions, and I thought it would be interesting to go through them (italics original; boldface mine; I cut a great deal of text*):

1) Demonstrate that evolutionary research is current and ongoing.... Post-Darwinian findings also present an excellent opportunity to teach about the process of science, and to show that the methods of evolutionary biology are the same approaches used in other areas of science.

2) Clarify that evolution is not a synonym for natural selection.... Creationists like to build a straw man by equating "evolution" with "natural selection," and then pointing out that natural selection is not the only mechanism of change. This error of falsely equating "evolution" with "natural selection" should be theirs, not the textbook's.

This is my favorite item:

3) Use fresh examples.... I thought if I read one more description of peppered moth evolution I would scream. Creationists attack these examples as "icons" of our field, and although their criticisms are often absurd, they are right to criticize the books for always using the same examples. If students are presented with the peppered moth example in every biology course they take (and most are), they begin to think that this must be one of a few examples of evolution by natural selection observed by humans. There are a myriad of other examples published in the scientific literature, and many of them are much more relevant to the students' lives than is the color of moth wings. It helps for students to read different examples to illustrate principles such as natural selection each time they take a new biology course.


4) Show how evolution is relevant to human lives.

5) Use examples of evolutionary biology from popular media.

This next one is pretty good too. I think it's often unmentioned because the authors of general biology textbooks aren't familiar with the literature:

6) Include experimental evolution. Experimental evolutionary studies have become commonplace over the past few decades, but students rarely read about these studies in their textbooks. Students should know that evolution is not just something that can be studied in an historical framework, but also something that can be observed directly in a laboratory or field experiment. They should also learn that evolutionary principles and techniques can and have been tested experimentally, and that techniques such as phylogenetic reconstruction have been subjected to experimental testing and have been shown to be highly accurate and effective. Ancient DNA sequences can be reconstructed both computationally and in the laboratory, and the function of ancient genes and proteins can now be studied directly. Moreover, evolutionary principles are being widely used to develop new compounds in the laboratory, and in vitro evolution is an excellent way to show an industrial application of evolutionary principles. Despite the many applications of in vitro evolution, this topic is rarely even mentioned in most introductory biology textbooks.

Onward again, glorious comrades:

7) Integrate evolution throughout the book.

8) Emphasize "tree-thinking." The diversity of life should not be discussed as a progressive trip through increasing complexity. Too many students already come into a biology course with "ladder of life" thinking. To counter this problem, they need to be exposed early and often to the tree of life, and to the interpretation and use of phylogenetic trees in general. They need to learn that all extant species are equally distant in evolutionary time from the common ancestor of all life, and that many new features have evolved in all lineages. They need to be exposed to the many uses of phylogenetic analyses as a way of interpreting and using biological variation.

9) Emphasize the diversity of life, not memorization of scientific names.... Many students panic upon seeing a Latinized name, and skip it without even trying to sound it out. Common names should be used where possible, but they should be well defined and then used consistently. Moreover, why burden students with subjective taxonomic ranks? Evolutionary biologists understand that ranks in classification are subjective and have no equivalency across groups, and yet many instructors still expect students to learn whether a particular taxon is a "phylum" or a "class." Students can learn and understand biological hierarchy without being burdened with this "knowledge." We need to teach the hierarchy of the tree of life, but rank names do more to hinder than to help in this process. For instance, introductory biology students should know that they are primates, mammals, amniotes, tetrapods, vertebrates, chordates, deuterostomes, animals, and eukaryotes. They should understand that these are hierarchically nested groups, and know what features we share in common with other members of these groups.

Regarding the last point, do state achievement exams require that students know classic taxonomic hierarchy? Just a thought. Onto the last point:

10) Emphasize the great magnitude of evolutionary time..... I think we do a disservice to students when we speak of "microevolution" and "macroevolution," as if they are fundamentally different processes, rather than simply different time frames.

Good, bad? Any additions to the list? Discuss.

*As a dues-paying member of the Society for the Society of Evolution, I think it's ridiculous that general, 'public-service' articles like this one are behind a paywall. It doesn't seem to jibe with the stated mission of "the promotion of the study of organic evolution."


More like this

Last month's issue of Evolution (aka Evolution Int J Org Evolution, aka Evolution (Lawrence Kansas), aka some other confusing way of referring to the journal published by the Society for the Study of Evolution) contains two articles on teaching evolution. The first is on creating museum exhibitions…
One of the problems that many people have with evolution is not religious, but philosophical. If evolution is true, they think, then we are at sea - nothing is fixed, nothing is determinate, all coherence is gone, as Donne famously lamented of the death of the two-sphere universe and physics. This…
Alan Leshner, the head of the American Association for the Advancement of Science, has written an article concerning the recent controversy in Georgia over evolution in science classes. What he writes seems to support my contention that all of the public handwringing over the superficial issue of…
OK, this is really ancient. It started as my written prelims (various answers to various questions by different committeee members) back in November 1999, and even included some graphs I drew. Then I put some of that stuff together (mix and match, copy and paste) and posted (sans graphs) as a…

Your readers might like to know that Pearson educational actually will REMOVE THE EVOLUTION CHAPTER from its biology texts for shipment to e.g. Texas schools. A friend used to work for them and was shocked to find that this is a function of their "custom textbook" service. Other services they provide are removal of any mention of homosexuality, etc. Buyer beware!!

Please excuse my ignorance, but where might I read more about the distinction between 'evolution' and 'natural selection'? I use evolutionary theory in my cultural sociology classes all the time, and I want to be sure that I'm not reproducing this misunderstanding in my classes. Please advise.

[To my understanding, natural selection is the mechanism whereby evolution occurs.]

Todd-O: Natural selection is one mechanism by which evolution occurs, and the only method by which adaptations to environments evolve, but there are other mechanisms as well, including random genetic drift and (at the individual population level) effects of immigration and emigration on the gene pool.

I suggest including polyploidy in teaching. So many of our common foods are polyploid that their very existence makes the point that polyploidy isn't a vanishingly rare event.

Polyploidy is an example of sudden emergence of a new species wherein parent species A and B produce a new species, C, and species A, B, and C would coexist for some time, competing for much the same resources.

Thanks CCP and Roy. I think i have been teaching it correctly, just perhaps over-emphasizing natural selection, inasmuch as most of my social science and humanities majors haven't had much biology and it's enough of a chore to get them to understand natural selection. I do however discuss random genetic drift as the "raw stuff" upon which natural selection can act. Is that in incorrect characterization?

I particularly like suggestion #2. Too often people are taught that natural selection and evolution are the same thing.

This may not apply for middle/high school textbooks, but college level books could definitely use fresh examples, the "pepper moth fatigue" it something I've grumbled to myself about about in the past, not only because I have heard it in literally every biology class I've taken since high school, but because I have indeed heard creationist students claiming that it's always used because science is so limited on evidence for "real evolution happening."

I think all of the items listed are very good points!

Hi, great to be in the company of scientist and educators,
I had a biology class 2 years ago (my age 52 at the time),
no text book, great teacher and good lab manual. I am wondering about the conection between recent advances, like stem cells etc, and there relation to the discoveries around
evolution....are new advances based on data collected while searchings evolution?

Clarify that evolution is not a synonym for natural selection.... Creationists like to build a straw man by equating "evolution" with "natural selection," and then pointing out that natural selection is not the only mechanism of change. This error of falsely equating "evolution" with "natural selection" should be theirs, not the textbook's