Saturday, January 29, 2011

Few High School Biology Teachers Accurately Teach Evolution

I hate to bag on my own colleagues, but the evidence is overwhelming: most high school biology teachers either do not teach evolution or undermine their own teaching by giving nods and winks to creationist ideas. (See Most high school biology teachers don’t endorse evolution, by Valerie Strauss.)


Tom Schmal

The result is that few U.S. high school students are really being taught evolution in an accurate or comprehensible way. Not only is this unfair to students who graduate believing they have mastered biology, when many have not, but it is a violation of teachers’ responsibility to accurately teach the content standards, including the scientific process (how scientists obtain data, analyze it and determine the validity of their hypotheses).  

Here are some of the details from Strauss’ article:
  • Only 28% of biology teachers consistently teach the National Science Teachers Association (NSTA) recommended evolution curriculum,
  • Around 13% of biology teachers explicitly include creationism or intelligent design for at least part of their curriculum
  • The remaining 60% either fail to explain the scientific process sufficiently, undermine the authority of evolution experts, or legitimize creationist arguments
  • Many teach evolutionary biology as if it is only applicable to molecular processes, but not to populations or the process of speciation.
  • Many tell students that they don’t have to “believe in evolution, but they have to know it for tests, which, for many students, implies that it is just one of many explanations that may or may not be true.
  • Others tell students to decide for themselves what to believe, even though scientists are as certain of the validity of evolution as they are about any other scientific fact. We would not tell students to decide for themselves if the Holocaust or slavery occurred (although I wonder, based on the evolution data, if there are many biology teachers who are also climate deniers).

This is Not Simply a Problem of Religious Teachers Refusing to Do Their Jobs
Just like a Christian pharmacist should be required to sell all legal drugs, including birth control, a Christian biology teacher should be required to teach the content standards, including evolution. However, the problem is not just an issue of religious activists deliberately refusing to do their jobs. For some teachers, the last two examples above (e.g., “you don’t have to believe; just know it for tests” and “you decide what to believe”) may result more from a desire to respect their students’ cultural and religious beliefs and not insult or alienate them, than from their own religious biases or activism. I regularly have students tell me that they don’t have to learn evolution because it’s against their religion. My response is, “Well, actually you do. It is an important part of biology and it is in the content standards. Furthermore, it is impossible to understand other parts of biology without a foundation in evolution. Evolution helps scientists to develop new medicines, understand certain diseases and even make predictions about climate change.”

My response is not insulting or demeaning, nor does it undermine the science by implying that evolution is just one of many explanations that one can choose to believe, or not. On the contrary, it emphasizes that evolution is a lynchpin of biology, not just a stand-alone branch of the discipline. It is important to emphasize that evolution can be taught and misconceptions about it can be corrected, without engaging in the kind of hostile and insulting discourse expressed by people like Richard Dawkins. This sort of behavior probably does more to shut down students’ curiosity and openness to new ideas than to dispel their faith-based misconceptions.

In order to correct misconceptions is important to clarify the scientific process, particularly the meaning of the word “theory,” which many people misuse to mean “belief” or “opinion,” rather than its actual scientific meaning: “fact, based on a collection of related hypotheses that have been repeatedly verified.” Also, before I even get into the nuts and bolts of evolution, I emphasize the distinction between the scientific process, which is evidence-based, and faith-based thinking, where one believes without (or despite) evidence. I even go so far as to tell students that in certain circumstances faith-based thought is sometimes the most effective way to think (for example, having faith in oneself can help one remain motivated and focused during sports or academic challenges), but that in science, evidence is required, lots of it, and it must be verifiable by independent researchers using controlled experiments. Faith that a scientific hypothesis is right (without evidence) can lead to deadly consequences.

Another problem is that many science teachers have little or no experience doing “bench” science, having earned a degree in biology and then a teaching credential without having worked in a lab. As a result, they sometimes do not fully understand the scientific process themselves. For example, many cannot explain why a randomized, double blind, controlled study is more compelling than anecdotal evidence. Even doctors sometimes have this problem. Consider all the times you have heard doctors give advice based on their anecdotal experience with other patients.

Many Americans (including some biology teachers) do not truly understand evolution, making it difficult to believe and even harder to teach. This is due in part to the considerable misunderstandings and oversimplifications that are perpetuated in our culture (e.g., “we came from monkeys,” which implies that monkeys gave birth to humans or had sex with humans; in contrast to the idea that we share a common ancestor).

Even without the misconceptions, evolution is not an easy theory to understand. For example, the idea that an organ as complex as the human eye could be the result of random mutations and natural selection seems really far-fetched, until one realizes that the rudiments of vision, proteins that sense and respond to light, have existed for millions of years and have been utilized in sensory organs of animals that existed long before the evolution of the modern eye. It is also difficult to really get a handle on the slow rate of random mutations and how they can accrue in organisms without some background in biochemistry. For example, I don’t think that most biology teachers understand or teach that human DNA polymerase, the enzyme that builds new DNA molecules during replication, has a natural mutation rate of about 10-8.

Of course none of this is to say that there aren’t creationist biology teachers who deliberately try to undermine the teaching of evolution. A recent Gallop poll shows that 40% of Americans believe in young Earth creationism (i.e., the Earth and all its life were created by God 10,000 years ago), while another 38% believe in a form of evolution with God playing a role in it. No doubt some of these folks have made it into biology classrooms as teachers.


  1. As long as people confuse their belief systems with scientific fact-based studies there will always be this tension. What's startling to me is that we praise everything scientific except those things that conflict with beliefs (usually religion based). Either scientists are to be accepted or not; you can't have it both ways.

  2. There are plenty of people who do want it both ways (science for their toys and medicines, but not evolution). There are also those who believe evolution, but don't trust western medicine.

    Nevertheless, scientists should only be accepted when they have really done compelling research. Unfortunately, there are far too many cases of scientists who've made bogus claims, either through sloppiness or deliberate fraud.

  3. In an otherwise well reasoned article, I don't think you are being fair when you describe Richard Dawkins efforts to promote critical thinking as follows.
    "It is important to emphasize that evolution can be taught and misconceptions about it can be corrected, without engaging in the kind of hostile and insulting discourse expressed by people like Richard Dawkins."
    Is daring to question the irrational basis of religion insulting? I think not. Bad ideas deserve to be challenged - using evidence.
    Demanding 'respect' and attacking those who don't show it is the only weapon the religious have left.

  4. I do not find the questioning of the irrational basis of religion insulting. On the contrary, I find it essential and courageous and appreciate that Dawkins has chosen to confront irrational thinking head on.

    However, Dawkins' tone and style are excessively provocative and sometimes verge on abusive. For example, he often calls people ignorant, which may be true, but how many people will take such criticism constructively rather than as an insult?

  5. Please understand: it's not about evolution, it's about any science which contradicts the literal bible. Whether by evolution or special creation, the fossil record clearly shows this progression: invertebrates, fish, amphibians, reptiles, then birds and mammals. Thus says geology. But this is not the order of creation found in the bible. So, when it comes to the order of appearance, which is wrong, the bible or geology? Here the creationist mouth either closes or denies geology, either of which casts serious doubt on their anti-evolution rhetoric. Again, it's not about evolution but any science which contradicts a literal bible. Evolution is just the creationist's favorite whipping boy.