Three speakers at the convocation specifically addressed the difficulties teachers can face in the classroom when they teach evolution. None had a way to avoid controversy, but all had ways to deal with it.
Paul Strode, who teaches biology at Fairview High School in Boulder, Colorado, grew up in Indiana and went to a small liberal arts college, where he took courses in zoology, genetics, and ecology but learned very little about evolution. After he moved to Seattle to teach high school biology, he left the evolution chapter to the end of the year, as many teachers do, and warned his students the day before the session began that the class was going to discuss evolution because it was part of the curriculum. “I was frightened and nervous, and sure enough the next day when I came in to the classroom there were pamphlets on my desk about things that I couldn’t answer, because I had no way to answer them.” He went ahead and taught the unit, but “for the next seven years I avoided evolution completely. That scared the heck out of me.”
Many new teachers fear that their students will discover that they do not know everything, said Strode. “I didn’t want anyone in my classroom, I didn’t want the principal there, and I didn’t want another teacher to watch me teach, because I thought I might be found out.”
After eight years of teaching, Strode went to the University of Illinois for a Ph.D. in ecology and environmental science. “That’s when it was
revealed to me that I had no idea how science worked.” One day one of his thesis advisers asked him what hypothesis he was testing with his research. Strode gave her an answer, and she replied, “No. Those are your predictions. What are your hypotheses?” He reformulated his answer, and she said, “No, you’re still giving me predictions. You don’t know what hypotheses are, do you?”
“That was almost the deal breaker for me,” Strode recalled. “I almost walked home and quit because I thought, ‘What am I doing—and what have I done for eight years as a high school teacher—having no idea that science is a hypothesis-based form of inquiry?’”
Strode finished his doctorate and moved to Boulder to teach high school with a whole new outlook. He realized that many of the lab activities he had done in his first eight years of teaching were canned experiments where the outcome was obvious; if students did not get the right answer, they were worried. He started designing activities where the data were messy and the outcome was unknown. He realized that his students were smart enough to learn about statistics, so he taught them about confidence intervals and the analysis of variance.
He also was asked to co-author a book called Why Evolution Works and Creationism Fails (Young and Strode, 2009). “That forced me to realize that I wasn’t doing as good a job as I could teaching evolutionary theory in the classroom.” He began teaching evolution every day so that the subject was woven throughout the curriculum and was not confined to a single unit at the end.
To avoid the problems he experienced, said Strode, teachers need preparation courses on both evolutionary science and on avoiding denialism, whether the subject is evolution, climate change, vaccination, or any other controversial subject. They also need to understand how science works and how that relates to the teaching of evolution. The solution, he said, starts “with kids understanding how science works and teachers understanding how science works and teaching teachers in a more effective way.”
Betty Carvellas, who taught science for 39 years at the middle and high school levels and who served as a member of the authoring committee of Science, Evolution, and Creationism (National Academy of Sciences and Institute of Medicine, 2008), taught her students that they do not necessarily need to “believe” in evolution, but they do need to understand the scientific evidence demonstrating that evolution is a fact. She would not have been comfortable saying this early in her career, but when she did become comfortable doing so, it allowed her to do two things. It
informed her students that evolution would be a part of every experiment they did all year long. It also gave them the right to say, “I don’t believe in evolution,” because, as Carvellas said, “I don’t believe in evolution either. A belief is one thing, and a scientific fact is something altogether different.”
Evolutionary thinking is not possible without scientific thinking, she said. If students do not understand the nature of science, the processes of science, and the limitations of science, they are not going to understand evolution. These ideas about scientific thinking have to be built starting in kindergarten. Young students love to do the things that develop scientific understanding, such as asking questions, developing models, planning and carrying out investigations, analyzing and interpreting data, thinking mathematically, constructing explanations, and engaging in argument from evidence. “If they haven’t had that opportunity [by high school], they’re fearful of this because they don’t know what the right answer is.”
Teachers in earlier grades, starting in kindergarten, do not need to mention evolution, Carvellas said, but they must introduce the concepts that will make an understanding of evolution possible. This will require more professional development and resources for teachers. For example, the new frameworks for science education call for students at the end of second grade to understand that some of the plants and animals that once lived on earth are no longer found anywhere, although others now living resemble them in some ways (National Research Council, 2011). Second graders are not ready to understand common ancestry, but later in their schooling they will have an easier time understanding the concept. “If you plant those seeds and let kids work with them, it’s going to make our lives so much easier when they get to high school and college.”
Carvellas built evolution into her entire course, whether the subject was ecology, environmental change, genetics, or any other subject. By the time her class studied evolution directly, they had a basis for how it happens, they were more motivated, and they were more interested.
Many teachers in some parts of the country cannot deal with the conflicts with parents and students who confront them on a daily basis, so they avoid evolution. One teacher told Carvellas that her students “would challenge her on day one, and if they found out that she accepted evolution, they would make her life miserable for the entire school year.”
But Carvellas also said that students are quite receptive to being told that what their friends told them is wrong. “They love finding out that [a misconception] isn’t true and here is why we know it’s not true and here’s what really works.… They love knowing more than their friends know.”
David Hillis, Alfred W. Roark Centennial Professor in Natural Sciences at the University of Texas and a member of the National Academy of Sciences, said that he has been teaching biology for 30 years and always in states where evolution is controversial, including Kansas, Florida, and Texas. At the beginning of his introductory biology courses in college, or even his advanced evolution courses, students often tell him that they have a religious problem with evolution. Rather than confronting them, Hillis asks them to try to keep an open mind, listen to what he has to say about evolution, and then come back to him if they still have problems. “In 30 years, I’ve never had a student come back to me. I’ve never had a comment on an evaluation complaining about evolution.” People who have religious objections to evolution largely do not know what evolution is. Many of their objections can be overcome by “simply addressing that ignorance.”
In teaching evolution, Hillis starts with familiar examples from the present and recent past and gradually works his way toward the distant past. “They can see that the exact same concepts and things that they know and can understand in the present or in the recent past apply to the ancient past.”
He also seeks to show how the mechanisms of evolution that can be observed today are sufficient to account for major evolutionary changes over long periods of time. Students need to grasp the deep time of Earth to understand why these mechanisms have had enough time to work. “They have a hard time understanding the difference between a thousand and a million, much less between a million and a billion. Once they have used mechanisms to help them understand the depth of time we’re talking about, and you start multiplying the kind of changes we see over short time to those longer times, they begin to understand how this can all work.”
Students need to understand that evolution has practical applications by learning about examples of evolution in action. They need to be shown applications of evolution in human health, agriculture, industry, and basic science.
Instructors also need to demonstrate that evolution is an experimental and an observational science, said Hillis. Few biology courses or textbooks emphasize the point that all the basic mechanisms of evolution can be observed directly and confirmed experimentally, and classrooms should feature these demonstrations and experiments to a much greater extent.
Finally, as emphasized throughout the convocation, evolution needs to be applied in every unit of biology courses and in every chapter of biology textbooks. Textbooks still need to have chapters on evolution to
explain the details of the process, said Hillis, just as advanced courses on evolution will still be necessary. But evolution should not be limited to those sessions or classes.
National Academy of Sciences and Institute of Medicine. 2008. Science, Evolution, and Creationism. Washington, DC: The National Academies Press.
National Research Council. 2011. A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas. Washington, DC: The National Academies Press.
Young, M., and Strode, P. K. 2009. Why Evolution Works and Creationism Fails. Piscataway, NJ: Rutgers University Press.
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