The Debate That Shouldn’t Be

By Deborah J. Ausman

Does evolution happen? Since Darwin proposed his theory in 1859, the debate has raged, particularly in the popular press and American public schools. In a survey of 34 countries, more adults in the United States reject the concept of evolution than in any other country but Turkey (Science, August 11, 2006: Vol. 313. no. 5788, pp. 765–766). Such results perplex Rice scientists studying evolutionary processes. None of the researchers interviewed for this article consider their work particularly controversial because of its focus on evolution, and they seemed puzzled and even infuriated by the often heated debates between proponents on both sides of the issue. For them, the question is not whether evolution happens, but how.

“The simplicity of Darwin’s theory is what makes it so compelling,” says Michael Kohn. “Evolution is just change over time. Scientists argue viciously about the mechanisms driving it, the dynamics, the relative intensities of strains, and timescales, but we do not argue about the process, because it’s everywhere around us.”

“Darwin’s principles are as important to biology as Einstein’s theories are to physics,” says Yousif Shamoo. “They completely changed the way the field works and how people think about biology.” The way evolutionary biologists go about science is no different from how others go about science, he says, yet people don’t protest when Einstein’s theories are taught in a physics class.

“Physicists and chemists don’t have to justify their disciplines,” says David Queller. “They can start from the assumption that the science is sound, and if there weren’t something to evolutionary biology it would be gone by now given the number of people who hate it.” Queller acknowledges that in BIOS 334, which provides an overview of biological evolution aimed at upper-level biology majors, he spends several introductory lectures citing the “evidence” for evolution.

Interestingly enough, scientists who are religious often are able to segment the two belief systems. Shamoo mentions a personal friend who is a brilliant engineer and also very religious. “He doesn’t use his belief in God to design an airplane engine,” Shamoo says. “But he also doesn’t use the laws of physics and math to design his religion. Science and religion are two very different parts of our world, and we shouldn’t try to supplant one with the other. ”

Janet Siefert, who is as open about her strong religious beliefs as she is about her work with microbes in Cuatro Ciénegas, agrees that science and religion should occupy separate spheres. Even as she points her science back 3.5 million years, Siefert recognizes and respects its limitations. “There is clearly something in me that desires to understand how life happened at the beginning,” she says. “But it’s particularly unsatisfying because there’s really no way to know if you’re even close to right.”

Some of the biggest questions that humans have, such as where life evolved first and what that life might have looked like, will never be answered definitely, Joff Silberg points out. But he says he can design experiments to explain some of the possibilities, such as how temperature affects protein evolution. “I can never say where life evolved,” he says, “but I can show how difficult neutral evolution is at 37˚C compared to 100˚C. This doesn’t tell us where life evolved, but it does tell us something about the biophysical and environmental conditions that are necessary for it to evolve.”

All of the scientists interviewed for this article admitted that acceptance of evolution is not a prerequisite for studying science, and even biologists can avoid taking courses in evolution if they choose. Shamoo says he occasionally has students in his biochemistry course mention that they don’t believe in evolution, and while he acknowledges that students are free to make up their own minds, he also points out that expertise in biology requires a working and accurate understanding of the process. “I tell them that not believing is fine,” he says, “but this information is going to be on the test and this is the answer they need to provide.”

Wilson says evolution is generally accepted in the social sciences as a useful theory, though many researchers get by without it. “The real questions,” he says, “are what does evolution tell us and what insights does it provide into how people interact within cultures and institutions?”

The same applies in the sciences, though Kohn notes that a scientific perspective that omits evolution may be incomplete. “I am color blind,” he explains. “So I look at those plates with dots on them, and I just don’t see that 3 or that 8. It’s genetic—it doesn’t mean I’m not smart, it just means I can’t see something someone else can. And I don’t even necessarily know that I’m missing out on anything. I imagine that’s what it’s like for those that can’t ‘see’ evolution.”

—Deborah J. Ausman