The debate over the origin of species is no longer a matter of biblical creationism versus Darwinian evolution. Today, while some Christians continue hold to a strictly literal, six-day creation as depicted in Genesis, others attempt to reconcile evolution and creation by suggesting that God set up the universe, including the laws of chemistry and physics, and left nature to take its course.
Such "theistic evolutionists" believe as a matter of faith that God is behind evolution, but they deny that reason and science can detect any evidence of God's creative plan.
Today a growing number of scientists and philosophers, however, advocate "intelligent design theory," which holds that many features of biological organisms are too complex to have resulted from the Darwinian mechanisms of random genetic variation and natural selection.
They believe that the most natural and best rational inference from the data is to some kind of design or purpose in biology.
The disagreement between theistic evolutionists and intelligent design theorists is sometimes heated. For example, a priest-astronomer at the Vatican Observatory recently derided intelligent-design theory as a form of "creationism" and as "religion pretending to be science."
To explore intelligent design theory more fully, Our Sunday Visitor recently spoke with Dr. Michael J. Behe, a biochemist who has been identified with intelligent design theory from its emergence in the 1990s.
Behe is a professor of biological sciences at Lehigh University in Pennsylvania, a senior fellow of Discovery Institute and author of the landmark book "Darwin's Black Box" (Simon & Schuster, $14).
Our Sunday Visitor: What is the intelligent-design (ID) movement?
Dr. Michael J. Behe: ID is an umbrella term for scientists and philosophers who are beginning to question and separate out the claims of an implicit materialist philosophy that have grown up alongside, indeed almost inside, modern science.
We are told by "Science" with a capital "s" that the universe is just matter and energy in motion, but it turns out that actual evidence of science does not necessarily support that philosophical claim.
More specifically in my field of biology, the ID movement is beginning to question the claims of neo-Darwinian evolutionary theory and to propose that a better scientific explanation of the data is some kind of intelligent cause rather than random variation and natural selection.
OSV: How did you become interested in questions of design in biology? Did your Catholic faith play a role in that process?
Behe: No. Throughout my undergraduate and graduate training I was taught that the neo-Darwinian theory of evolution was one of the most well-founded theories in all of modern science and I never doubted that.
I didn't see any conflict with my faith because I figured that if God wanted to use a process that appeared to science to be random and undirected, that was His prerogative. I accepted Darwin's theory until I had been teaching at the university level for some years.
At that point I began to have questions.
OSV: Did your questions have to do with religion?
Behe: No. I was a scientist trying to make sense of the data.
OSV: So what caused you, as a scientist, to begin to doubt neo-Darwinism?
Behe: I had always been taught that evolution worked through small step-wise changes in organisms that provided some advantage and were then fixed in a part of the population. These gradual changes over time (micro-evolution) could then accumulate and result in major morphological and species-level changes (macro-evolution).
For example, Darwin postulated that a light-sensitive spot could gradually and fortuitously change into first a very crude eye, and later a complex mammalian eye through accumulation of tiny changes. These accounts of large-scale changes sounded plausible to me.
But the plausibility of undirected evolution as an explanation changed completely for me when, after reading a book by another scientist who was skeptical of Darwinism, I finally started considering how evolution would have to work at the level of biochemistry.
OSV: What's special about biochemistry? If Darwinian evolution can work for large-scale changes, why not small?
Behe: I'm not saying Darwinism does actually work for large-scale changes, only that that seemed plausible to me for many years when I was relying on the expertise of others in my profession.
But thinking of the problem from the perspective of biochemistry changed everything.
Behe: Biochemistry is the nuts-and bolts level of life. When we get to biochemistry we're dealing with discrete protein structures with incredibly complex, specific arrangements.
We know that to go from one kind of complex protein structure or function or cascade to another requires many changes.
We can, in effect, quantify those changes and their probability. We can determine with some certainty if any of the intermediate steps between one kind of protein arrangement and another kind are useful to the organism, and thus could be "promoted" or "fixed" by natural selection, allowing a Darwinian-style transition from one to the other.
When we look at all this molecular information-which amounts to a kind of engineering analysis of the micro-structure of life-the situation looks grim for neo-Darwinism.
OSV: What in biochemistry raises major problems for neo-Darwinism?
Behe: First of all, as I talked about in detail in my book "Darwin's Black Box," we find in nature many sub-cellular systems that are irreducibly complex. By that I mean they involve a number of interrelated parts or subsystems all of which are necessary for the system to function.
This fact is a huge problem for neo-Darwinism, since by hypothesis there is no plan or purpose or intelligence in biological change that can direct the development of the parts in order to be assembled later into the whole.
Second, even at the most basic level of protein folding, the latest data is showing that it is incredibly difficult and unlikely for a single protein with, say, a certain three-dimensional structure called a "fold" that results in a certain enyzmic function to evolve into another protein with a different fold and function.
OSV: So at the micro level you find discontinuity rather than continuity?
Behe: The funny thing is that at a macro level there is discontinuity too. But we can readily imagine, say, transitional forms between species, and literally draw a series of paintings in which one form morphs into another. At the micro level, however, we not only find deep discontinuity, but in addition our imaginations run up against hard facts.
It's hard even to imagine how to get function and benefit in the structural space "between" irreducibly complex systems, or even protein folds.
To get from one useful protein fold to another requires crossing a huge distance of amino acid sequence space, and in between there are no known folds that can be fixed by natural selection.
OSV: You've been talking about nothing but science. Why do people always associate questions about evolution with religious ideas?
Behe: To a certain extent evolution is concerned with where we came from and who we are, concerns that overlap with religious questions.
In the 19th and early 20th centuries, Darwinism became the dominant theory among intellectuals (including biologists)-not so much because of overwhelming scientific evidence but because it provided a coherent materialistic and atheistic "genesis myth" that completely fit and reinforced the intellectual zeitgeist, which was of course Nietzsche's "death of God."
OSV: What happened in your case?
Behe: Religious questions only arose for me when I began to realize that for many people Darwinism is itself a kind of ersatz religion. That doesn't-or shouldn't-affect the scientific questions, but it certainly raises some interesting questions about the relation between science, faith, morals, and culture.
OSV: Given the serious scientific issues, why do some Christians reject ID and accuse proponents of ID of being "creationists" and doing "religion pretending to be science"?
Behe: First, I think there are many social factors involved. We're taught to believe in a Darwinian view everywhere we turn in our culture-in schools, TV shows, magazines.
So, we believe it because everyone else believes it. In this social context, some Christians hear leading scientists deride anything other than Darwinism or a materialistic view of life as "creationism," so Christians assume that the authorities must be on solid ground. That turns out not to be correct.
Second, there is a common misperception that the ID movement is claiming that God has miraculously intervened to cause directly a number of critical events in the history of life.
ID does not deny that there may be secondary causes or "laws" of biology that explain the natural history of life; we are only determined to follow the evidence wherever it leads. If we discover new secondary causes that explain biological phenomena, fine.
Any "law" that can produce the kind of interlocking and deep complexity that we find in biology implies some kind of underlying intelligence, just as the increasingly elegant and elaborate mathematical laws of physics and the "fine-tuning' found in cosmology imply intelligence behind them.
Finally, I think many Christians have lost sight of the fact that there is a long tradition in Western thought-going back at least to the pagan Aristotle-of looking at the world scientifically but being open to rational explanations of natural things that transcend nature. In other words, empirical science may imply causes that transcend nature, and philosophy can then investigate those causes, all without leaving the domain of human reason an entering into the question of religion proper.
OSV: Is ID, then, ultimately a philosophical rather than a scientific question after all?
Behe: Philosophy can contribute a lot to this debate, but I'm just a simple biologist trying to follow the evidence of my specialized science where it leads.
I think the actual evidence of biochemistry leads powerfully away from the mechanistic-materialistic science of Darwinism to some kind of new formulation of biological science in terms of plan, purpose, and intelligence.
Philosophers of nature can help put it all in the right categories. We're at the very beginning of a paradigm shift in biology and nobody really knows where this will end up.
Mark Ryland is vice president of the Discovery Institute and serves on the boards Christendom College and the International Theological Institute.