Insights & Perspectives
Dobzhansky was right: Let's tell the students
Article first published online: 22 APR 2010
Copyright © 2010 WILEY Periodicals, Inc.
Volume 32, Issue 5, pages 372–374, May 2010
How to Cite
Scott, E. C. (2010), Dobzhansky was right: Let's tell the students. Bioessays, 32: 372–374. doi: 10.1002/bies.200900190
- Issue published online: 22 APR 2010
- Article first published online: 22 APR 2010
At a state university recently, I was commiserating with the biology professors about the familiar statistics: how only about half of United States citizens accept evolution,1 and how scientists and the public strikingly differ on their acceptance of evolution.2 A general theme seemed to emerge: that their undergraduates, newly arrived from high school, were unaware of the centrality of evolution to biology. The conversation thus inevitably drifted to high school instruction.
“My son's teacher knows nothing about evolution. I mean, not the first thing,” said one frustrated professor. “She doesn't teach it because she doesn't know anything about it.”
“She's a credentialed teacher, right? So she was a biology major?” I asked.
“Oh, sure. It's a good school.”
“So where do you suppose she learned her science?” I inquired.
There was a pause. “Um, well, I hate to say it, but probably here.”
I let the thought hover a moment.
“So if teachers don't know enough about evolution to teach it, or know how science works….”He finished the thought: “Yeah, I guess that buck stops here, doesn't it.”
Well, that is where one of the bucks stops, anyway. The sources of antievolutionism are many, and therefore the solutions to the problem will require multiple approaches in multiple arenas. But clearly one reason why many Americans reject evolution is that they do not know what it is, not having learned adequately about evolution at school or at university. Nor have most Americans encountered an accurate portrayal of evolution in the media.
University instructors are responsible for a good part of the general public's ignorance about evolution: it is they who teach the university students who become the science teachers in our schools, as well as the students who become members of the educated public (school board members, legislators, leaders of society, producers of television programs and movies, and “influentials” in general). University scientists therefore have a special responsibility – and opportunity – to help to cope with the antievolution problem in the United States. And one thing they can do is to think about how they teach evolution. Is evolution as central, integrated, and pervasive in their syllabus as it is in biologic research? Will their students realize that – in the words of Theodosius Dobzhansky's famous 1973 article for high school biology teachers3 – nothing in biology makes sense except in the light of evolution?
Dobzhansky wrote that evolution changes biology from a “pile of sundry facts” to a “meaningful picture as a whole” (p. 129). The fact that living things had common ancestors makes sense of the sundry facts of evolution: evolution tells you why things in biology are the way they are, and not some other way. Why do mitochondria have DNA? A eukaryotic cell has its “own” DNA for cell division; mitochondrial DNA is redundant. The answer to this puzzle is that cells, like everything in biology, have an evolutionary history, and if we are explicit about this history when we teach students about cells, cell structure will “make sense” to students.
It is not just cells, of course. Evolution makes sense of myriad biological observations. All land vertebrates have four limbs. Why? Are four limbs especially suited to land locomotion? Well, not especially. Insects have six limbs, arachnids have eight, and millipedes have – lots. So why do land vertebrates have four limbs, and not more or fewer? Land vertebrates are descended from an aquatic vertebrate that had two limbs in front and two limbs in back; they are tetrapods rather than hexapods or octopods because of common ancestry: they inherited this trait from an aquatic common ancestor.
The unifying power of evolution enables us to make predictions. Most mammals have teeth, but some mammals (pangolins, baleen whales, and anteaters) lack them. If all mammals descended with modifications from a common, toothed, mammalian ancestor, we would expect that edentulous mammals would have genes for teeth, but that these genes would be inactivated. Recently, molecular biologists published sequences of the genes affecting enamel development in mammalian lineages. They found that frameshift and other mutations inactivated these genes in lineages leading to toothless mammalian forms, as evolution would predict.4
Evolution also helps us think about how to answer questions which are still puzzles. One of my colleagues was asked by a high school teacher: “Why are there no green mammals?” A good question! Green coloration is found in all other vertebrates, but not mammals. Why? I do not know the answer (I am a physical anthropologist, not a biochemist!). But I will bet that any scientist looking for the answer to this question would look not only at how color is produced in the hair of mammals but also at how color is produced in the scales and feathers of other amniotes, and then look at gene trees. Of course, hair, scales, and feathers share genes because they are epithelial structures – another evolutionary fact. Scientists routinely think in evolutionary terms about the solutions to problems in biology, but for some reason we rarely explicitly teach problem solving in biology this way. As a result, students rarely see evolution as being central to the discipline.
If university instructors do not make explicit the centrality of evolution to biology, we should not be surprised when students complete their courses ignorant of evolution. One professor at a well-regarded West Coast State University told me that he “doesn't teach evolution” in his genetics class because “we have a whole course on evolution for majors.” He was rightly proud of requiring a capstone course in evolution for biology majors (required also by Brigham Young and Notre Dame, by the way), but why should he assume that only biology majors should learn about the organizing principle of his discipline? Why is not evolution taught throughout the curriculum, so that those non-major students can also benefit from biology's making sense?
So one contribution scientists can make to solving the problem of antievolutionism is to do a better job teaching evolution. This means at a minimum helping students to realize that evolution is the concept that binds together the disparate field of biology, that makes sense of all these facts that students learn in their course of study. To do this means making explicit the concept of common ancestry in every course, not just a capstone course in evolution offered to majors at the end of their 4 years. (There are other steps, too, including improving their pedagogical techniques, but that is a topic for another day.)5 When students repeatedly hear that life is like it is because living things have descended with modification from common ancestors, they will internalize it. Evidence from polls shows us that they are missing this principle now. When university graduates' understanding of biology is grounded in a solid scientific, theoretical, and evidentiary foundation of evolution, citizens of tomorrow will be equipped to take that knowledge and to utilize it in a variety of circumstances whether they become teachers, scientists, school board members, politicians, businessmen, journalists, policymakers, or “merely” voters – whose votes may determine science-friendly or -unfriendly legislators.
Imparting a better understanding of evolution (and of the nature of science, I might add) to college biology students is a long-range project, and necessary though it is, it is not sufficient to solve the problem of antievolutionism. It is also necessary that scientists become active citizen advocates for good science education in their communities and states. As documented on the website of the National Center for Science Education (NCSE, see www.ncse.com), every year there are assaults on the teaching of evolution in dozens of states. (And those are only the ones we report. Often, in order to protect a student's or a teacher's privacy, or in order not to exacerbate a difficult situation, we will work below the radar.) American education is decentralized; decisions are made at the local or, at most, the state level; citizens need to let policymakers know their views about the teaching of evolution and “alternatives” such as creation science, intelligent design, “evidence against evolution,” “critical analysis of evolution,” “strengths and weaknesses of evolution,” and other euphemisms for creationism.
Because scientists know what science is, and why evolution is valid science – not scientifically controversial, contrary to creationist portrayals6 – their expertise is particularly important at hearings of local and state school boards and state legislatures. Similarly, because of their expertise, scientists' letters to editors and calls or appearances on talk radio have weight beyond that of the average citizen. Not every scientist is suited to every task, but any scientist can write a letter or sign a statement supporting or protesting a policy.
There are many ways for scientists to become involved. The American Institute for Biological Sciences and NCSE maintain a series of state email lists for scientists and other interested people to learn about the controversy and to discuss tactics and strategy. These lists vary considerably in terms of traffic and interest. Some are virtually inactive, only occasionally circulating news updates on the creationism/evolution controversy; some have more traffic, especially if there is antievolution legislation pending, or if science education standards are under review. (There is much room for improvement in the way evolution is treated in state science education standards, by the way. Where does your state stand?7)
Scientists have taken leading roles in most of the “citizens for science” groups that have grown up around the country in response to challenges to evolution education. In Kansas, Georgia, Texas, Ohio, Oklahoma, Minnesota, and many other states, the participation of scientists has been crucial in the positive outcomes of sometimes protracted controversies over science education standards or legislation (see http://ncse.com/news for details). A list of such organizations can be found at http://ncse.com/taking-action. If you are interested in starting such an organization, contact one of them for advice, or contact NCSE. Monitoring of local and state decisions about evolution education is critical; no one can do that better than local citizens, and every scientist is a local citizen – somewhere!
And, of course, scientists should acquaint themselves with the basic arguments of the antievolutionists, and at least the Cliffs Notes version of rebuttals to them, so that when these arguments are raised in public discourse, they can recognize and refute them. What we call the pillars of creationism are to be found throughout the creationist literature. They are that (1) evolution is weak science; (2) evolution is incompatible with (Christian) faith; and (3) it is only fair to “balance” the teaching of evolution with an alternative (whether creation science or intelligent design or “evidence against evolution,” etc.). Brief rebuttals are: (1) Evolution is a core principle of science, supported by independent and converging lines of evidence. (2) Evolution is accepted on its merits by scientists and laypeople of all faiths and of none. (3) It is hardly fair to pretend to students that non-scientific views are scientifically valid and thus to miseducate them, handicapping them for further study. More on the rebuttals to the Pillars can be found in many online resources, especially www.talkorigins.org, and in a variety of books on the creationism/evolution controversy.8
If the problem of antievolutionism was only one of science, we could stop here. As my friend Kenneth Miller likes to quip, “We have the fossils. We win.” We indeed have the fossils, and we have the molecules, the embryos, the biogeography, and the rest of the science, too. But we do not have the victory, because the problem of antievolutionism is as much – or more – an issue of politics as it is of science. There is a huge disconnect between what we as scientists know and what the public believes. In a recent Pew Research Center poll, 97% of scientist members of the American Association of the Advancement of Science agreed with the statement “Humans and other living things have evolved over time,” while only 61% of the general public agreed (although that is a much higher number than usually obtained for the general public). Moreover, when the public was asked whether scientists generally agree that humans have evolved, nearly three in ten responded no. That is a lot of people who do not recognize the consensus on evolution within the scientific community.2
So scientists need to speak up when evolution is under attack in their schools. And more generally, scientists have a special responsibility to work to ensure a scientifically literate citizenry, which includes educating them in the importance of evolution to science, and in science education. In a nation where the majority of financial and institutional support for science predominantly depends on the public, it is in the best interests of neither science nor our nation that the public understanding of a major principle of science continues in its dismally low state.
- 1National Science Board. 2008. Science and Engineering Indicators 2008. Arlington, VA: National Science Foundation.
- 2Pew Forum on Religion and Public Life. 2009. Public Praises Science; Scientists Fault Public, Media; Scientific Achievements Less Prominent Than a Decade Ago. Washington, DC: Pew Forum on Religion and Public Life.
- 31973. Nothing in biology makes sense except in the light of evolution. Am Biol Teacher 25: 125–9..
- 62007. Explore Evolution. Melbourne and London: Hill House Publishers., , , , .
- 72009. Why science standards are important to a strong science curriculum and how states measure up. Evol Educ Outreach 2: 359–71., .
- 82009. Creationism vs Evolution: An Introduction. Westport, CT: Greenwood..