Human Nature

The Structure of Scientific Evolutions

Evolution’s place in a created universe.

The quarrel between religion and evolution has taken an interesting turn. Instead of attacking religion, some Darwinists have embraced it as a product of human evolution. Now they’re debating to what extent this evolution was biological. Evolution and biology are coming apart.

This is a tricky concept to grapple with in today’s biologically dominated era of science. Let me try to explain where we are. Three years ago, while on a Templeton fellowship at the University of Cambridge, I heard one of those ideas that not only sticks in your head but starts to reorganize your thinking. The idea was convergence. The speaker was Simon Conway Morris, the Cambridge paleontologist and author of Life’s Solution. Conway Morris affirmed evolution as a mechanical explanation of animal and human development. But he also argued that evolution takes place in an ordered world. Because similar features evolve repeatedly in different contexts, there must be something about the world that favors such features.

There’s nothing inherently spooky or religious about this idea. We have a straightforward model of it in the well-known pattern of phase changes. At certain temperatures and pressures, this or that element will naturally change from solid to liquid to gas. The fact that such transitions can be explained mechanically doesn’t erase the fact that the points at which they’ll happen can be predicted independently. In that sense, they’re caused not just by heating or cooling but by the pre-existing structure of the universe.

Conway Morris takes this idea a step further. He suggests that such structural causation might occur not just in physics but in biology. This is a gamble, since biology is more complex than physics or chemistry. In physics or chemistry, you can make solid predictions from a limited set of data and laws. Biology is a lot messier. With the emergence of life, organisms that arose from physics and chemistry begin to operate according to new patterns. Functional explanations replace chemical ones. You can’t assume that an underlying order constrains biological evolution in the same way that the underlying order of chemistry constrains phase changes. But Conway Morris suggests, based on evolutionary convergence, that to some extent it does.

If he’s right, two much bigger questions start to become serious. One is how far this architecture of the universe extends. If it influences developments at the chemical and biological levels, does it extend to the next level of complexity, the mind? How about the level beyond that, society? Are there mental and cultural laws? Does some pre-existing order favor, and thereby produce by adaptation or selection, certain kinds of cultural development?

The other question is what to think of this architecture. Is it just the way things are? Is it creation? Is it God?

If you’re interested in either of these questions—and as the cutting edge of biological and cultural development, you should be—the guy whose work you ought to read is Robert Wright. Two confessions up front: One, I consider Bob a friend. Two, for several years (well, it seemed like years—maybe it was months), he routinely kicked my ass at squash. So I gave up squash and took up science writing. And guess what? Now he kicks my ass at science writing. (Check out his latest Slate piece on shamans and their sex, money, and protection rackets.)

In a series of books— Three Scientists and Their Gods, The Moral Animal, and Nonzero—Wright has pushed the idea of pre-existing architecture from the chemical to the biological to the cultural level. He believes that the structure of our world has favored the evolution of societies based on peace, commerce, reciprocal altruism, and mutual benefit. His latest book, The Evolution of God, takes this argument further: God may or may not have shaped biological and cultural evolution (just by establishing an initial algorithm), but these processes have definitely shaped Him. The evolution of the human brain led to religion, and our ideas about God have subsequently changed in concert with cultural progress. On the whole, despite history’s ups and downs, God has become more peaceful, more beneficent, and more compatible with a scientific understanding of the world.

Not everyone is thrilled with Wright’s version of God. To many religious people, a nonpersonal deity that never intervenes in the ordered world is no deity at all. But the more interesting critique has come from scientists. Many of them don’t like theism, even in Wright’s deistic form. They prefer simple explanations. They think that biological evolution can account for religion’s emergence and that this form of explanation is uniquely God-free.

The most notable of these scientific critics is Nicholas Wade, a reporter for the New York Times. Wade is the author of Before the Dawn, an ingenious reconstruction of human prehistory from genetic and linguistic evidence. This fall, he has another book coming out: The Faith Instinct. In a preview on the Times Web site, he agrees with Wright that “morality has a genetic basis and may well have evolved over the millennia into forms that are objectively higher.” But Wade thinks religion’s original function was clear:

to instill, through group cohesion, morality within a group and hostility toward those outside it. So in very early human societies, groups with strong religious behavior would have prevailed over less cohesive adversaries. We are descended from the religious groups, the argument goes, and that is why everyone harbors a religious instinct. …

Wade concludes: “Natural selection also explains rather well how religious behavior would have conferred such advantages on early human societies that it became a part of human nature.”

Wright disagrees. He calls religion “an incidental by-product” of biological evolution. “Religion arose out of a hodgepodge of genetically based mental mechanisms designed by natural selection for thoroughly mundane purposes,” he writes. Those mechanisms include conformist bias (believing what your peers believe, in order to get along), a tendency to explain events in terms of personal agency (since our mental machinery for thinking about causality evolved in the context of social interaction), and interest in remote control (a bias toward beliefs that promise influence over predators, diseases, and bad weather). Given these biases, we’re prone to believe in powerful, jealous, tempestuous personal deities.

But Wright doesn’t think our consequent religious belief systems evolved in the same way that these underlying mechanisms did. He argues that

biological evolution isn’t the only great “designer” at work on this planet. There is also cultural evolution: the selective transmission of “memes”—beliefs, habits, rituals, songs, technologies, theories, and so forth—from person to person. And one criterion that shapes cultural evolution is social utility; memes that are conductive to smooth functioning at the group level often have an advantage over memes that aren’t. Cultural evolution is what gave us modern corporations, modern government, and modern religion.

Wade calls this theory “a disappointment from the Darwinian perspective.” It isn’t “real evolution,” he concludes; it’s “just the development of ideas about God.” Therefore, “the God of [Wright’s] title owes nothing to Darwin.”

So who’s right in this debate? Is religion a product of natural selection, cultural evolution, or God’s truth?

Here’s one possibility: all of the above.

I agree with Wade that cultural evolution is an exaggerated metaphor. Wright asserts that “just as genes are transmitted from body to body, down the generations, memes are transmitted from mind to mind.” But that’s a stretch. Memes don’t pass from generation to generation the way genes do. One requires only procreation; the other requires parenting and education. For this reason, our cultural inheritance is vulnerable in a way that our biological inheritance isn’t.

On the other hand, I agree with Wright that biological evolution isn’t the only ordered process that shaped us. Life originally emerged from an architecture of physical and chemical laws. So natural selection isn’t the first level of the cosmic order; it’s at least the second or third. Why should we assume the architecture stops there? Shouldn’t we look for directional patterns in cultural history? If such patterns exist, they’ll be far more complicated than the patterns of biology, just as the patterns of biology are more complicated than the patterns of physics or chemistry. But science doesn’t promise that everything can be explained with the same ease, or even in the same terms. You have to face the world as it is and develop new tools when the old ones fail.

Natural selection has become a tremendous tool for understanding biology. But it wasn’t the first kind of science we invented, and it won’t be the last. The notion that major components of our society or its development, such as religion, must be explained entirely through natural selection is no more scientific than the notion that they must be explained through physics or chemistry. All of these sciences, these levels of order, work together. We are physical, chemical, biologically designed, culturally guided organisms.

If this complex, multitiered, gradually emerging architecture is the concept of God we’re heading toward, then yes, God owes plenty to Darwin. And Darwin owes plenty to God.

(Now playing at the Human Nature blog: 1) Two critiques of abortion reduction. 2) China’s new two-child policy. 3) Baseball and DNA testing.)