A task like memorizing the periodic table is a cakewalk compared to understanding human evolution. There are no simple experiments students can use to prove the evolutionary process, and then there's that troublesome word "theory."
Human evolution is a complex enough subject to teach even without the highly publicized struggle between those who embrace it as fact and those who believe it to be at odds with intelligent design or creationism. And teachers walk a fine line as they try to convey the evidence for evolution without coming off like they're trying to change a student's beliefs.
This year, Gale Sinatra will help bring together scholars from multiple fields to share findings about how such a controversial subject as evolution is taught and learned, and how our assumptions about a topic play into learning.
Sinatra, an educational psychology professor, and her co-investigators want to find out whether students understand the nature of science -- that it's a way to collect evidence about the world around us. "We want students to understand that science is not an infallible march to ultimate truth."
Joining Sinatra in the project are Sarah Brem, an associate professor of psychology in education at Arizona State University (ASU), and Margaret Evans, assistant research scientist at the University of Michigan's Center for Human Growth & Development Research. Brem takes a socio-cultural approach to the topic, while Evans is a developmental cognitive psychologist with experience in museum education. Coming from educational psychology, Sinatra is interested in the larger question of conceptual change -- how people shift their thinking about a topic they already know something about.
The trio won a grant for more than $200,000 from the National Science Foundation to take stock of the field of teaching and learning about evolution. The grant was awarded under a new program for Research and Evaluation on Education in Science and Engineering that's designed to corral several strands of research from different fields, in this case, biology, philosophy, cognitive science, and developmental psychology.
"It's almost like the proverbial blind man and the elephant," Sinatra says. "Researchers in all these different domains have been looking at this issue for years. Now it's time for everybody to talk to each other."
Ê×Ò³| Â鶹´«Ã½Ó³» 40 scholars from all over the country -- and some from outside the U.S. -- will meet in small groups in five cities throughout the year. Then the entire group will come to ASU next fall for a final conference to synthesize their work.
The Challenge in the Classroom
What the researchers discuss in the next year will have little to do with the controversies that have gripped the school systems in many states, where evolution has become a battleground between social conservatives and scientists. The meetings aren't intended to debate the merits of intelligent design or rehash the effects of placing stickers in textbooks to urge students to consider alternate views.
Instead, evolution will be used as a lens through which the scholars will look at problems in all science learning, Sinatra says. Evolution makes for a good case study of the social, cultural, curriculum design, and other issues that influence learning. "In evolution, these complexities are easier to see. It's a microcosm of complex systems for teaching and learning."
Neither will they be creating new standards for science educators, who already must meet a full slate of curriculum requirements. But their work may be able to help teachers overcome the preconceived ideas their students bring into the science classroom.
That's one of the key points Cheryl Wagner discusses as a teacher trainer for the Clark County School District (CCSD). Teachers need help recognizing students' preconceptions at the start of a course, Wagner says, and in knowing how to address them.
Many students, not just those with a religious or cultural bias against evolution, are genuinely perplexed about the difficult questions evolution raises. With the incorrect presumption that evolution says humans evolved from apes, students might wonder, "How can there still be apes?"
Such misguided preconceptions aren't limited to evolution. Students might think the moon's phases are caused by a shadow from the earth, Wagner says, or think that single genetic traits are passed on at random. They can have a lot of their own ideas about science topics that are either incorrect or incomplete.
"In the classroom I have to find out where my kids are. The conceptions they come in with might not be scientifically valid," Wagner says. "The students may do well on tests, but they may not understand the concepts when they've left. Then they go out of class with the same thoughts and misconceptions as when they came in."
There hasn't been widespread opposition to teaching evolution in Clark County schools, Wagner says, but at least two science teachers in the district declared that they would not teach it. "As a result, they're not teaching biology," Wagner says, because evolution is a mandated part of the curriculum.
Some researchers and educators are calling for more emphasis on teaching about the scientific process and the nature of science. "We tell students to use evidence to support their conclusions," Wagner says. "Unless we help them reason through it as a scientist, they won't have learned a topic."
Sinatra says science classes probably need to spend more time on how to develop scientific arguments and inquiry. Traditionally, the emphasis has been on scientific facts that can be memorized, such as species classification. But that's not enough, she says, because science changes.
"We need to tip the balance more toward the process of science than the content of science," Sinatra says.
Theoretical Arguments
One of the biggest gaps in evolution education comes down to the "theory" problem.
Evolution opponents have seized on the status of evolution as a theory, and have used it to suggest that the science behind it is still up for debate, Sinatra says. But the common and scientific definitions of "theory" are vastly different.
"Popularly we use the term 'theory' to mean a guess, but that's not how scientists use the term," Sinatra says. "They use it to mean something for which they have a great deal of evidence to report. The idea that there isn't any evidence, or that we aren't sure about the evidence, is incorrect."
CCSD's Wagner acknowledges that teachers could do a better job of explaining the difference. "There are definitely some educational kind of gaps where teachers know evolution and have been studying the series and textbooks, but they don't totally understand the process."
One reason might be that most teachers are educators first -- they're not expected or required to be professional scientists. "I never had a class specifically on evolution when I was in college," says Wagner, whose undergraduate degree is in microbiology. "What I've learned has been through biology courses with evolution components and through my own study and reading."
Peter Starkweather, a professor of biology, sees that disconnect in his UNLV classes. To scientists, evolution is a building block of biology, not a footnote, he says.
A good start to changing that would be to require more science education for prospective teachers, he says. That would not only improve the students' understanding of evolution, but teachers would also be better prepared to explain the issues to those who challenge them -- not just students, but parents, too.
"If we want incoming college freshmen to understand these concepts, we have to make sure the outgoing teachers do, too," Starkweather says. "I really think they ought to know biology with greater depth and greater confidence."
By the time they reach college, most students have forgotten the basics of their 10th grade biology classes, he says. "If I ask students what they know about evolution, it's essentially zero. They have caricatures." When he has asked students to define evolution in introductory biology classes, they usually respond "survival of the fittest."
"Then I ask, 'What does that mean?' Silence," Starkweather says.
Not Found in a Petri Dish
Evolution is a difficult process for anyone to understand, says Brem, the ASU professor who is one of Sinatra's co-principal investigators on the grant. It doesn't lend itself to tidy lab experiments and it relies on a vast number of variables in the environment -- thousands of organisms doing their own thing and reacting with their surroundings to produce an outcome. Boiling that down for a four-week lesson plan is tough.
"It's like predicting the stock market or traffic jams," she says. "There's a larger set of issues here than you usually come across in middle school science class. It's a really challenging topic."
Evolution's fluidity may be part of why some find it untrustworthy. Learning it is suited more to field work, Brem says, unlike a more law-driven field such as chemistry, which rewards you with the same thrilling, messy outcome every time you mix vinegar and baking soda.
"The kinds of arguments you have to make in evolution and biology are different from physics and chemistry. Those work the same way, every time, everywhere," Brem says. "With evolution, if you roll back time, something else would happen. You can't predict much."
One of the major arguments against evolution is that it's untestable, and that seems to fly in the face of what scientists normally demand. "One thing we teach is that science should be replicable. That's very difficult in evolution. It might make the arguments seem less satisfying, I think, because they work on different rules."
Starkweather, the biology professor, says the evolution backlash is part of a larger skepticism about unknowns in science. People want proof, or nothing. "Science has been hit with the accusation that, since we can't explain everything, then what we do know is wrong."
What helps students grasp the concepts of evolution when they can't build a project in a Petri dish? CCSD's Wagner finds it best to leave the humans out of the discussion when starting out. "That's where there are questions, and kids are going to shut their minds."
Teachers find more success in discussing evolution on the scale of simple organisms. They find issues that are familiar to students: mutations in the AIDS virus or the threat of antibioticresistant bacteria. Most high school students can relate to wondering why they have to finish their prescription even after they feel better.
Changing Knowledge, Not Beliefs
Everyday issues like virus mutations are the reason why evolution is a central component of biology education, Sinatra says. The goal for educators is not to change beliefs, but to fill in the gaps for those who don't yet have the complete picture on evolution.
"Our concern is teaching and learning about essential topics for scientific literacy. We're not focused on the controversy," she says. "What's interesting to me as an educational psychologist is how to teach about complex topics when people have a lot of pre-existing ideas."
But to explore this topic, you can't take religion out of the mix completely. That's why the trio of researchers invited Kenneth R. Miller to the discussion. A biology professor from Brown University, he wrote Finding Darwin's God: A Scientist's Search for Common Ground Between God and Evolution. "He's an example of one way people move beyond focusing on conflict and toward an appreciation of both their faith and science," Sinatra says.
Miller writes in his book, "As more than one scientist has said, the truly remarkable thing about the world is that it actually does make sense. The parts fit, the molecules interact, the darn thing works. To people of faith, what evolution says is that nature is complete. God fashioned a material world in which truly free, truly independent beings could evolve."
A team of German emotion researchers will also participate in the meetings to share their findings on how emotion and culture play a role even in the most rulebased subjects of math and science. ASU's Brem focuses on the social and cultural factors in learning, and how they can create assumptions about a topic, which is at the heart of the dispute between evolutionists and creationists.
"Although the political and cultural aspects of teaching evolution are the most publicly looked at, it's the area where we have the least amount of evidence -- how those beliefs affect learning," Brem says.
"Still, even if we could take all of the socio-cultural conflict out of evolution, it would be a really hard thing to learn."
