On the shelf by my desk is a slightly frayed book I treasure, a first edition of Charles Darwin’s On The Origin of Species, published in 1859 and given to my great grandfather on his graduation from college shortly after the end of the Civil War. By the turn of the century, when my grandfather went to college, Mr. Darwin’s theory of evolution by natural selection was taught as the foundation of biology throughout the country.
Then something happened. In the 1920s conservative religious groups began to argue against the teaching of evolution in our nation’s schools. Darwinism, they said, contradicted the revealed word of God in the bible and thus was a direct attack on their religious beliefs. Many of you will have read about the 1925 Scopes “monkey trial” or seen the move about it, Inherit the Wind. In the backwash of this controversy, evolution for the first time in this century disappeared from the schools. Textbook publishers and local school boards, in a wish to avoid the dispute, simply choose not to teach evolution. By 1959, a hundred years after Darwin’s book, a famous American geneticist cried in anguish “A hundred years without Darwin is enough!” What he meant was that the theory of evolution by natural selection has become the central operating concept of the science of Biology, organic evolution one of the most solidly validated facts of science. How could we continue to hide this truth from our children, crippling their understanding of science?
In the 1970s Darwin reappeared in our nation’s schools, part of the wave of concern about science that followed sputnik. Not for long, however. Cries from creationists for equal time in the classroom soon had evolution out of our classrooms again. Only in recent years, amid considerable uproar, have states like California succeeded in reforming their school curriculums, focusing on evolution as the central principle of biology. Not here, though. Darwinian evolution is still not taught as the core explanatory principle of biology in Illinois or Missouri schools. Evolution does not appear in the Illinois state science standards at all! In Missouri, this year’s “Show Me” science curriculum standards of the Missouri Department of Elementary and Secondary Education list 231 content standards — the things our students are to be taught about science — and the word “evolution” appears in only two of them. Darwin is not mentioned at all. By contrast, there are 21 content standards devoted to the cell-molecular theory of inheritance, and fully 36 to force and energy. This sort of lip service to the central idea of biology just doesn’t get the job done. We ought to be ashamed of not doing a better job of teaching our students. As we enter the new millennium, Illinois and Missouri’s science curriculum should be brought up to the standard of a century ago. It is high time we brought Darwin out of hiding.
What ought we to do to reform our curriculum? First and foremost, we should use evolution as an explanatorily principle as we introduce our children to biology. For example, instead of teaching students, as we do now, that mitochondria are tiny parts of cells that happen to carry out oxidative metabolism, we should tell them what scientists have known for decades, that mitochondria are in fact the relics of ancient oxidative bacteria long ago taken in by larger more advanced cells. They retain their ancient cell membranes and DNA chromosome, but are under the functional control of the cell in which they now reside. That mitochondria so resemble bacteria is not a mystery, but history. There are as many other examples as there are content standards in the Missouri curriculum. Evolution is an explanatory principle, and should be used as such, throughout the curriculum.
Second, we should teach evolution as an experimentally verifiable theory, not as some sort of assumption accepted like a religious precept. The study of evolution by biologists is a rich and exciting scientific field, full of enlightening and engaging research. What student could fail to be excited, and informed, when told of this experiment carried out on South American fish: Field biologists were studying a particular species of small fish that lives along a river below a waterfall. These guppies are grey and nondescript to avoid the larger fish which are their predators, and reproduce fast, making many babies because each baby has a significant chance of being eaten (no point in investing too much in any one baby as its chances for survival are small). The biologists found that other populations of the same species of guppy lived above the waterfall, where there are few predators — the large fish never made it up the waterfall. There, in the safe waters above the waterfall, the small fish are colorful to better attract mates (there is less danger of attracting predators), and invest more in reproduction, producing fewer but larger offspring (there is less danger an individual offspring will be eaten).
All this is as Darwin would have predicted. The little fish below the waterfall evolved adaptations (nondescript appearance, fast breeding) to cope with predators, while those above had no need to do so, and didn’t. But science is about testing predictions. To test the Darwinian prediction, scientists captured some of the nondescript guppies living in the dangerous environment below the waterfall, and released them into safety above the waterfall. In only a few generations these little fish began to resemble their more colorful cousins there, producing fewer, larger, and more colorful offspring. Evolution in action.
Evolution is important to teach in our schools because it explains biology as a science. It also makes biology a lot more fun to learn. Every parent with a child in Illinois or Missouri schools should insist he or she be given a chance to learn biology right. 140 years without Darwin are enough.