Only A Theory: Evolution and the Battle for America's Soul

by Kenneth R. Miller

Viking, 2008

Ken Miller is not preaching to the choir. Although he has a day job as an active research biologist at Brown University, Miller has spent more than two decades on the front lines of the battle over evolution as a writer, lecturer, and expert witness in court. During these two decades of culture war, he has come to realize that, although the stakes are high in this fight, sometimes the best tactic is the non-martial one: don't treat the American public as pawns in a propaganda war.

Miller starts with the assumption that most people will be fairly open-minded about evolution and intelligent design. Before they make a firm judgment on the role of evolution in our public schools, people genuinely want to know what the scientific status of evolution is, and whether intelligent design is truly a scientific challenger. Many previous books debunking evolution have missed people like this. Such books typically fall into two categories: necessary but dense, technical works that provide, in detail, the scientific community's best response to the claims of intelligent design advocates, and scathing, hard-hitting attacks that fire up those who already accept evolution, but turn off readers who are trying hard to understand this issue without being strongly biased either way. Only A Theory is a genuine attempt at persuasion, and its approach is a result of Dr. Miller's years of practice speaking to audiences who want to give both sides a fair shot.

Don't be fooled, however, into thinking that Miller is trying to find some mutually satisfactory middle ground. For those who want to know whether evolution really is good science, his answer is unambiguous - evolution is one of the most successful and important theories we have in biology. And what about intelligent design? Its advocates have not even attempted to make this a real scientific discipline; evolution is the only scientific game in town.

The book starts out with a nod to America's anti-establishment culture, and how such a culture has helped science thrive. "America is home to independent-minded individuals for whom a primary virtue is disrespect for authority," says Miller, and that disrespect is "the reason that our country has embraced science so thoroughly." Although the United States for a long time sat in the shadow of Europe's scientific dominance, a culture of independence helped US science grow - "getting ahead [in science] did not mean following the lead of a supervisor, a laboratory head, or a department chair."

So it's more than a little ironic that intelligent design advocates are accusing scientists of clinging blindly to orthodoxy, unwilling to recognize that a paradigm-shattering new science is about to overturn 150 years of evolutionary research. But rather than dismissing such claims as absurd on their face, Miller says OK, let's give them a fair shot:

"Do the antievolution and intelligent design movements represent genuine revolutionary scientific ideas? Has American individualism once again given rise to ground breaking science of the sort that would not be possible in a more authoritarian or hierarchical society?"

Giving Intelligent Design Its Due

Only A Theory takes up the challenge, looking one by one at intelligent design's big claims. In 26 accessible pages, Miller lays out intelligent design claims about the bacterial flagellum, the blood clotting cascade, and the information encoded in our DNA. What's unique about this chapter is that Miller sets up the anti-evolutionary arguments without rebuttal. Rather than tiring the reader with something along the lines of "intelligent design advocates say this, but evolutionary biologists say this," Miller gets the reader nodding along, setting the bar nice and high for evolution. As an example of intelligent design, "the flagellum certainly seems like the real deal, doesn't it?"

This strategy is brilliant. Miller's goal is to persuade, but how can you be persuasive in your rebuttal if your audience doesn't know the argument you are attacking? Miller sets the bar high for evolution because he knows scientists can meet the challenge. We don't need to short-change design's advocates by distorting their arguments, because science can in fact demolish them as they are.

After letting intelligent design have its best shot, Miller lowers the boom. At first glance, the bacterial flagellum sounds persuasive as an example of design, but how does design really stack up as a science? Genuine scientists aren't generally satisfied with just tossing ideas out there. To be successful, scientists have to embrace their ideas - they take them and test them by applying these ideas in detailed, novel situations.

A prime example of this is the fossil record. Miller notes that efforts to explain patterns of change observed in the fossil record have played a major role in the development of evolutionary science. He uses the evolution of the horse family to illustrate the level of detail at which scientists apply their ideas. Scientists have found fossils covering hundreds of extinct species and 55 million years of horse evolution. Using evidence from the fossil record, scientists have a detailed explanation for how the horse family developed, from a North American creature the size of a house cat to today's species that include horses, zebras, and donkeys. The fossils illustrate the evolutionary concepts of speciation and adaptive radiation, and scientists have correlated these developments with changes in climate and vegetation - exactly the types of environmental changes that evolutionary biologists expect to influence the evolutionary developments observed in the fossil record.

As Miller puts it, scientists have embraced evolution and applied it in detail to the horse fossil record. What about design? Have design advocates embraced their ideas? Where are their detailed alternate explanations for the horse fossil record? What would a detailed intelligent design theory look like in this case? Not much:

First, it would not consider [the horse family] a family at all. From the ID perspective, the relationships detailed in figure 3.1 aren't real, because descent with modification, which is another name for evolution, never actually took place. Those ancestor-descendant relationships so apparent to paleontologists are just an illusion. In fact, the evolutionary tree leading to modern horses isn't a tree at all, but just a collection of individual species, directly created by the designer, each without any relationship to the other. What happened over time is that the designer created a handful of little browsing species and then, as each one went extinct, he replaced it with a modified version. When those went extinct, he drafted another round of replacements, and then another, then another. Whatever one can say of this designer, he's persistent. He's also not very skillful, since just about everything he creates goes extinct relatively soon after its first appearance. Unless of course, constant extinction is part of his master plan.

Examining each major intelligent design claim one by one, we see that design advocates have repeatedly failed to take their own ideas seriously. In each case, from blood clotting to information in our DNA, evolutionary biologists have rolled up their sleeves and gotten their hands dirty, while design advocates have not conducted a single field study or lab experiment to test their ideas. And in fact their ideas turn out to be little more than negative arguments against evolutionary biology's explanations. At bottom, "even when presented with every opportunity to make their case, the defenders of design resorted to little more than saying 'It's not good enough for me' in the face of overwhelming evidence for evolution."

The Overwhelming Case for Evolution

Having disposed with intelligent design's claims to be a science, Miller next sets for himself the task of showing his readers just what some of that overwhelming evidence for evolution is. Many books have covered the same ground, but Miller has learned to pick easy-to-grasp examples that leave a lasting impression. He puts a lot of focus on recent developments that have come with the availability of thousands of genome DNA sequences and new experimental techniques that have led to the explosion of the science of evo-devo. What's most remarkable about all of these discoveries is that they all represent the most recent tests of evolutionary theory. It was possible for things to have turned out differently - we could have cracked open our genome and discovered that its structure strongly contradicted the core claims of evolutionary theory. Instead, modern genome sciences have yet again vindicated Darwin. This isn't the place to reproduce Miller's detailed examples here (plus the book is short and very readable - it's worth making the trip to Borders or your local library). But the science has come so far that we can conclude that "we really do know enough about the mechanism of evolutionary change to account for the large scale changes that produce genuine novelty. As a science, evolution keeps getting better and better at explaining the biological world.

Where do Humans Fit In?

We've come a long way in our discussion with the honestly curious reader. Miller has laid out what intelligent design is, how it fails to be a science, and he has shown that evolutionary biology, by contrast, is a thriving science that is overwhelmingly supported by what we observe in the natural world. But Miller knows this isn't enough - inevitably after his lectures, someone asks the big question:

"How can you tell me that I'm just an animal? How can you say that I'm no better than the beasts? That the only things that matter in life are to struggle, survive, and mate? There's just got to be much more to life than that."

Personally, I don't understand the angst. I don't understand why we have to somehow prove ourselves better than animals. If I live a fulfilling life, nurturing family relationships and friendships, exercising my mind, enjoying the beauty of the world around us, that's enough, no matter where we came from. Just because we can trace our ancestry back a million years to non-human animals doesn't lessen the value of the personal relationships in my life, nor does it make me less bound to act morally. There is more to life that just struggling, surviving, and mating - it's obvious in our everyday activities, and the fact that we're related to apes doesn't change it.

But for many people the angst is real, and here someone like Miller, who is genuinely religious, has a big role to play in our national conversation over evolution. His most important point is that evolution is not random, it is contingent. If we rewound the tape of life, and replayed evolutionary history on our planet, would we still get intelligent beings? Evolutionary biologist Stephen Jay Gould famously said absolutely not, but Miller says not so fast. He points to the repeated examples of convergent evolution in life - eyes, wings, and brains have evolved independently and repeatedly on this planet. Both vertebrates and cephalopods have managed to evolve species with sophisticated eyes and intelligent brains. Nothing on earth right now competes with human intelligence of course, but it is not unreasonable to think that if you replayed life on earth over and over and over, you would, perhaps more often than not, end up with intelligent beings who could fill a role similar to ours.

What this means then is that we are not, as some critics of evolution would have it, just a "mistake of nature." There are many options available for finding meaning in our lives, and Miller suggests that "the great value of science is that it speaks to a common human culture of rational understanding, and that culture is accessible both within and outside of a religious context." He is suggesting that we can and should defuse 'evolution versus creation' as a conflict between religion and atheism. In fact, science can be actually be a place of common ground for the religious and the non-religious.

The Stakes Are High

Valuing that potentially common culture of science is critical, because the stakes in the fight between evolution and design are high. This is not a curriculum conflict over an esoteric branch of science that can safely be ignored. Our very ability to keep science working in our culture is at stake. To illustrate, Miller quotes Allan Bloom, author of The Closing of the American Mind:

The danger [today's students] have been taught to fear is not error but intolerance. Relativism is necessary to openness, and this is the virtue, the only virtue, which all primary education for more than fifty years has dedicated itself to incubating... The point is not to correct the mistakes and really be right, rather it is not to think you are right at all.

Bloom thought the natural sciences were immune to this - science is about correcting mistakes and being as right as we can be given the evidence, not about accepting all theories as equal in the name of tolerance. But now intelligent design is trying to change the rules of the game. Unable to succeed in demonstrating design with the scientific method as it currently stands, they advocate changing the scientific method itself to allow religious explanations. This is what a minority on the Kansas State School Board wrote in 2005:

The current definition of science is intended to reflect a concept called methodological naturalism, which irrefutably assumes that cause-and-effect laws (as of physics and chemistry) are adequate to account for all phenomena and that teleological or design conceptions of nature are invalid. Although called a "method of science," the effect of its use is to limit inquiry (and permissible explanations) and thus to promote the philosophy of Naturalism...

In other words, its not fair that science doesn't allow supernatural explanations. If intelligent design advocates could change the rules of science, then invocations of God's hand would be just as valid as "cause-and-effect laws."

Miller is right that these are high stakes, and the intelligent design movement sees it too. Miller quotes a leading design advocate, William Dembski:

The implications of intelligent design are radical in the true sense of this much overused word. The question posed by intelligent design is not how we should do science and theology in light of the triumph of Enlightenment rationalism and scientific naturalism. The question is rather how we should do science and theology in light of the impending collapse of Enlightenment rationalism and scientific naturalism. These ideologies are on the way out...because they are bankrupt.

That science is bankrupt would surprise anyone who follows the uninterrupted stream of spectacular advances found week after week in science journals, not to mention anyone who enjoys the ubiquitous technology that springs from modern science. The scientific method isn't perfect, and not all of its products have been benign, but it forms a core element of our society's success in the modern world. If we let design advocates destroy science education, our place as a world leader in science and technology will gradually decline, and within a generation or two we will have completely forfeited our leadership in science. The scientific community can only thrive in a culture that values science - by funding it, by teaching it to our children, and by letting it enrich our individual lives, whether it's the science that brings us laptops and iPods or the science that lets us look up at a pitch black expanse of night sky and understand that were are made of stuff that was produced in the furnaces of the stars.

If you only want to read one book on our national discussion about evolution, make it Only A Theory. Ken Miller's aim is persuasion, not polemics, and our society will benefit from the conversation he is leading.

Have you read the book? Share your thoughts!

Next month's Scientific Blogging Sunday Book Club will be here at Adaptive Complexity on November 16th. We'll be discussing Charles Thorpe's Oppenheimer The Tragic Intellect. Read that book or any of the other great recent Oppenheimer biographies, and let's talk.