How Quantum Physics Can Teach Biologists About Evolution

How Quantum Physics Can Teach Biologists About Evolution
Essay, by CORNELIA DEAN - 7/5/2005, New York Times, original
In the fall of 1900, a young German physicist, Max Planck, began making calculations about the glow emitted by objects heated to high temperature. In retrospect, it seems like a small-bore problem, just the task to give a young scientist at the beginning of his career.

Biologists are fighting to preserve the teaching of evolution in schools. But if the question sounds minor, Planck's answer was not. His work led him to discover a new world, the bizarre realm of quantum mechanics, where matter is both a particle and a wave and where the predictable stability of Newton gives way to probabilistic uncertainty.

As Dennis Overbye of The New York Times once put it in these pages, Planck had grasped "a loose thread that when tugged would eventually unravel the entire fabric of what had passed for reality."

Physicists reeled. But physics survived. And once they got over their shock, scientists began testing Planck's ideas with observation and experiment, work that eventually produced computer chips, lasers, CAT scans and a host of other useful technologies - all made possible through our new understanding of the way the world works.

Biologists might do well to keep Planck in mind as they confront creationism and "intelligent design" and battle to preserve the teaching of evolution in public schools.

Usually, when confronting the opponents of evolution, biologists make the case that evolution should be taught because it is true.

They cite radiocarbon dating (more correctly "isotope geology") to show that Earth is billions of years old, not a few thousand years old, as some creationists would have it. Biologists cite research on microbes, or the eye, or the biology of the cell to shoot down arguments that life is so "irreducibly complex" that only a supernatural force or agent could have called it into being, as intelligent designers would have it.

And when scientists named Steve (hundreds of them by now) decided to advance the cause of evolution in the classroom and honor the evolutionary theorist Stephen Jay Gould by forming "Project Steve," the T-shirts they printed said in part, "Evolution is a vital, well-supported, unifying principle of the biological sciences, and the scientific evidence is overwhelmingly in favor of the idea that all living things share a common ancestry."

The battling biologists are right. But someone uneducated in the scientific method who listens to the arguments over evolution could be forgiven for thinking that they boil down to "my theory is better than your theory," with both sides preaching with theological fervor.

Scientists don't talk often enough or loud enough about the real strength of evolution - not that it is correct, but that it meets the definition of science.

It's not that they ignore the idea - the National Center for Science Education, sponsor of Project Steve, makes the point on its Web site, and organizations like the American Association for the Advancement of Science do, too. But biologists do not emphasize it as they might.

Science looks to explain nature through nature (the works of God rather than the words of God, as Darwin himself is said to have put it), and its predictions can be tested by observation and experimentation.

Scientists form hypotheses, devise ways to test them, analyze the data that they collect and then decide whether the results support or undermine their hypotheses.

This process has produced centuries of useful knowledge and fascinating discovery.

But it is messy, a mixed-up dance of two steps forward, one step back; dud ideas; blind alleys; and things that turn out to be not exactly what they seemed.

So it is hardly surprising that in the decades since Darwin developed the ideas he outlined in The Origin of Species, other biologists have suggested modifications or new ideas about this or that aspect of his great idea. Still other researchers, making their own observations or conducting other experiments, have refuted them or tried to.

For example, biologists argue about the degree to which evolution moves smoothly or progresses in fits and starts, a Gould-ian theory called punctuated equilibrium. This intellectual turmoil is not evidence of the weakness of the evolutionary thinking, as some critics have said. It is proof of the robustness of the scientific method.

And if this messy process were to produce an alternative to evolution that better explains nature and better meets the tests of experiment and observation, biologists would have to revise their ideas or even scrap them.

That would be a stunning shock, comparable to the shock that swept physics in the post-Planck decades of the 20th century. But biology would deal with it. And whoever initiated this shock would be at least as big a figure in biology as Planck is in physics.

"The supposed 'data contradicting evolution' do not exist," a Steve, Dr. Steve Rissing, a biologist at Ohio State University, said in an e-mail message.

But if they did, Dr. Rissing added, "I sure would want to be the scientist publishing them. Think of it - the covers of Nature and Science, and Newsweek and Time, too!"

It is evolution's acceptance of nature as the only true scientific authority and its capacity to fall in the face of a more effective explanation that make evolution science, far more than its mere correctness.

That is the difficulty faced by advocates of creationism and intelligent design. It is possible to believe in evolution and believe in God. Plenty of biologists do. But their deity is not a creator or intelligent agent at work in the material world in ways that transcend nature and its laws. That would be a matter of faith, not science.