Teaching students to be 'competent jurors' on evolution
PORT ORCHARD, WASH.
I am a public high school biology teacher, and I do an unusual thing. I teach my students more than they have to know about evolution. I push them to behave like competent jurors - not just to swallow what some authority figure tells them to believe - not even me - but rather to critically analyze, with an open mind, the evidence set before them.
Scientific theories have come and gone for centuries, replaced by better ones as new evidence arises. There has always been controversy in science and tremendous opposition to those who challenge the orthodoxy of the day. An effective way to teach science is to explore some of these controversies.
Teenagers, not surprisingly, find this approach exhilarating.
When I note that contrary to their large and monolithic biology textbook, some highly credentialed scientists insist that there are limitations to Darwin's theory, the students perk up.
And when I note that some current biology textbooks contain widely discredited evidence for Neo-Darwinism - a synthesis of Darwin's theory of evolution and Gregor Mendel's theory of genetics - the last of the sleepy looks in the classroom usually vanishes.
Skepticism for its own sake isn't the goal here, but it's important for students to realize that even respected scientists have peddled fraudulent evidence in defense of a pet scientific dogma. A few examples my students learn about are Ernst Haeckel's faked embryo drawingsand the infamous Piltdown Man - fossils of a primitive hominid that turned out to be a hoax.
I also expose students to the reputable evidence for evolution. They learn about some of the pillars of evolutionary theory - genetically altered fruit flies, the evolution of antibiotic resistance in bacteria and insecticide resistance in bugs, how breeding programs change domestic species, and how oscillating climates affect the beak size of certain kinds of finches. These and other examples demonstrate that organisms are capable of change over time.
What is the significance, I ask my students, of these microevolutionary changes? Can they be extrapolated to explain macroevolution - that is, evolution from one type of creature to a fundamentally different kind?
I also dissect these evidences using recent discoveries that have raised important questions among evolutionary biologists.