Evolution by Design
By Jonathan Wells
By shifting the evolutionary paradigm from one that rejects design to one that accepts it, scientists could explain various observations that Darwinian theory has difficulty accounting for.
Jonathan Wells holds doctorates in both biology (Berkeley) and theology (Yale). He is currently a postdoctoral research biologist in the Department of Molecular and Cell Biology, University of California, Berkeley, and a fellow of the Discovery Institute in Seattle.
Adapted with permission from the International Conference on the Unity of the Sciences. The original of this paper was presented at the Twenty-first International Conference on the Unity of the Sciences, which met in Washington, D.C., in November 1997.
Before the twentieth century, most Western scientists believed that God created living things by design. Belief in God was part of the very fabric of Western civilization; and by viewing the world through the spectacles of faith, people saw it as God's handiwork. In the words of John Henry Newman, "I believe in design because I believe in God; not in a God because I see design."
In the eighteenth and nineteenth centuries, however, some thinkers reversed the traditional logic to argue from design to God's existence. William Paley wrote in Natural Theology (1802) that someone crossing a heath and finding a watch would see that "its several parts are framed and put together for a purpose" and would conclude that it had been designed by a watchmaker. Analogously, Paley argued, one could conclude that living things are designed by God.
Darwin's exclusion of design
Charles Darwin was born into this intellectual environment in 1809. By the time his Origin of Species was published in 1859, Darwin had become convinced that the design that Paley claimed to see in living things was an illusion. According to Darwin, what appears to be design in living things can be explained naturalistically as the result of random variations and natural selection. [In this paper, "naturalism" and "naturalistic" refer to the philosophical doctrine that the physical universe is the whole of reality and that ideas and the supernatural are human projections.]
Darwin argued that just as domestic livestock can be modified by selecting certain variants for breeding, so wild species are modified by a "natural selection" due to competition for survival. According to Darwin, the continuation of such "descent with modification" over millions of years produced all living things from one or a few original organisms. He saw no room for design in this process. When Harvard botanist Asa Gray proposed that God had designed the variations on which natural selection operated, Darwin rejected the idea and concluded his 1868 Variation of Animals and Plants Under Domestication with a refutation of design. According to Darwin, the products of random variation and natural selection cannot be regarded as designed; and human beings, as the latest in a long series of undesigned results, are the least designed of all.
Darwin's modern followers concur. In 1967, paleontologist George Gaylord Simpson wrote: "Man is the result of a purposeless and natural process that did not have him in mind" (The Meaning of Evolution, revised edition). In 1970, molecular biologist and Nobel laureate Jacques Monod announced that "the mechanism of Darwinism is at last securely founded," and thus "man has to understand that he is a mere accident" (quoted in H.F. Judson's The Eighth Day of Creation, 1979). And in 1986, zoologist Richard Dawkins wrote a best-selling book titled The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design.
But the "evidence" that Dawkins cites in The Blind Watchmaker consists almost entirely of computer simulations. He argues that Darwinism would have to be true even if there were no evidence for it, because short of postulating the existence of a deity (which Dawkins rejects), Darwin's theory of "cumulative selection, by slow and gradual degrees, is ... the only workable explanation that has ever been proposed, for the existence of life's complex design." In other words, what persuades Dawkins that Darwinian evolution is true is not the evidence, but the fact that it is the only tenable naturalistic explanation for the history of life. As he writes in the book's opening chapter, "Darwin made it possible to be an intellectually fulfilled atheist."
Evolutionary biologists are virtually unanimous in their rejection of design, though some (such as paleontologist Stephen Jay Gould) sharply disagree with Dawkins over the sufficiency of Darwin's mechanism of gradual selection. Yet if one wishes to exclude design on scientific grounds, one must do so on the basis of a demonstrated mechanism; mere descent with modification is not enough. This point is unintentionally illustrated by biologist Tim Berra in Evolution and the Myth of Creationism (1990):
If you look at a 1953 Corvette and compare it to the latest model, only the most general resemblances are evident, but if you compare a 1953 and a 1954 Corvette, side by side, then a 1954 and a 1955 model, and so on, the descent with modification is overwhelmingly obvious. This is what paleontologists do with fossils, and the evidence is so solid and comprehensive that it cannot be denied by reasonable people.
But the historical development of the Corvette, which Berra calls "descent with modification," is undeniably due to construction according to preexisting plans--that is, design. Ironically, therefore, his analogy shows that descent with modification is compatible with design.
Evidence has been accumulating for decades, however, that Darwin's mechanism fails to account for major features of evolution. The fossil record (especially where it is most complete) lacks the innumerable transitional forms that Darwin's theory predicts; artificial breeding (no matter how intense or protracted) fails to produce the major modifications that his theory requires; and embryonic development (as revealed by modern comparative embryology) is radically different from Darwinian expectations. According to molecular biologist Michael Denton (Evolution: A Theory in Crisis, 1986), not "one single empirical discovery or scientific advance since 1859" has validated Darwin's theory that large-scale evolution is caused by natural selection acting on random variations.
Given the empirical anomalies, and the sharp disagreement over mechanism between Dawkins and Gould, it is clear that the modern Darwinian denial of design rests on nonempirical grounds. It is no longer an inference from evidence but an a priori assumption based on a commitment to naturalistic philosophy.
One good metaphysical a priori deserves another. Since Darwinists have shifted their ground from science to philosophy, it is legitimate to ask whether their axiomatic exclusion of design is the only logical possibility. The answer, obviously, is no. Before Darwin, design was taken for granted by most Western scientists, and even today, a significant number of scientists view the world as designed.
For the remainder of this paper, I will assume that living things are designed--not necessarily in every detail, but in at least certain aspects. Specifically, I will assume that the human species was planned before life began and that the history of life is the record of how this plan was implemented.
The Darwinian account of the history of life begins with the most primitive organisms and works its way forward to the appearance of human beings. Although this is how events actually unfolded, from a design perspective the idea of human beings came first, followed by a plan to achieve the goal. In a sense, then, the plan took shape by working backward from the goal.1
What would the plan have to include? Any plan that places humans as the intended outcome would have to provide for such basic needs as food, water, and a suitable environment. It can be argued that humans have other needs as well, including social interactions, intellectual stimulation, and aesthetic enjoyment. Here I will focus entirely on physical needs.
When human beings first appeared, the environment must have been congenial to unprotected human life. From a design perspective, this human-friendly environment was planned. Advocates of the Anthropic Principle have pointed out that such an environment was possible only because the fundamental physical constants of the universe had the precise values they have. But these constants are consistent with a wide range of environments, whereas life requires a relatively narrow range of temperature, pressure, and other physical parameters. Therefore, in addition to the universal constants, suitable local conditions would have needed to be part of the design as well.
Humans use oxygen in their metabolism and release carbon dioxide as a waste product. Therefore, suitable local conditions must include an atmosphere containing these gases and a mechanism that regenerates oxygen from carbon dioxide. This mechanism is photosynthesis, which is carried out by green plants. It uses energy from the sun and also produces carbohydrates--another raw material in human metabolism. Photosynthesis is a remarkably efficient system for maintaining an environment congenial to human life. Unless some other mechanism is shown to be capable of fulfilling the same role, a design perspective implies that organisms very much like green plants were a necessary part of the original plan.
In addition to carbohydrates, the human body needs various other nutrients, including specific amino acids, minerals, and vitamins. Our nutritional needs are quite complex and must be met on a regular basis, so we are absolutely dependent on a variety of food sources. These are found in the plants and animals around us. Since our needs include complex organic molecules found only in other living things, those organisms are necessary for our existence.
Whatever organisms may have been necessary for human nutrition, their existence required a balanced ecosystem that accommodated their needs. The original plan must have included a self-sustaining biosphere in which reproduction and growth were balanced by death and decay. The balance among organisms in an ecosystem is normally quite complex, and ecologists frequently discover that organisms previously thought to be unessential are necessary elements in that balance. It is thus clear that planning for human beings requires planning for many other organisms as well.
Getting from there to here
The need for large numbers of organisms becomes even more evident when we try to imagine how human beings appeared on what was originally a lifeless planet. Although there is no consensus among paleogeologists about atmospheric conditions on the primitive earth, those conditions were almost certainly different from today's. The first organisms must have been capable of surviving in those conditions and transforming them into an environment more favorable to human life.
In other words, primitive organisms had to pave the way for the stable ecosystems we see today. A barren planet had to become a garden; soils containing organic nutrients for land plants had to be produced. To use current biological terminology, ecological niches were filled by organisms adapted to survive under local conditions. Those organisms then transformed their conditions, and other living things took over.
Producing a congenial environment with nutritious foods, while necessary, would not have been sufficient. Some people believe that the first human beings were created fully grown. But even if we ignore psychological considerations and restrict ourselves to physical ones, birth and growth are essential aspects of human beings as we know them. A creature that begins life without passing through birth and childhood would be so unlike us that we could not regard it as truly human, regardless of how great the superficial resemblance. And because human babies are totally dependent on other creatures for their survival during early development, animals capable of raising the first human babies must have been a necessary part of the original plan.
Human babies need milk to survive and grow, so mammals had to exist before humans appeared. And not just any mammal. The first human baby presumably had to be nurtured by a creature very much like itself--a humanlike primate. This creature, in turn, could only have been nurtured by a creature intermediate in some respects between it and a more primitive mammal. In other words, a plan for the emergence of human beings must have included something like the succession of prehistoric forms we find in the fossil record.
Similar reasoning could be applied to earlier episodes in the history of life. For example, just as mammals were necessary predecessors of the first humans, mammallike reptiles were presumably needed to precede the first mammals, and so on. The emergence of humans thus depended on a progression of creatures that increasingly resembled us.
Although this process is superficially similar to the Darwinian notion of common descent, design theory differs from the latter in maintaining that predecessors need not be biological ancestors but only providers of essential nourishment and protection. Successive organisms are "related" in the sense that they represent planned stages in the history of life, but they are not genetically related as ancestors and descendants. A planned succession would not require the innumerable transitional forms that Darwin predicted. Design theory is thus more compatible than Darwinism with the discontinuities found in the fossil record.
Design theory also does a better job than Darwin's theory in accounting for homology. According to Darwin, features in diverse organisms are structurally similar ("homologous") because they are inherited from a common ancestor. Biological inheritance implies that such features are more similar because they are produced by similar genes or developmental pathways, but this implication is contradicted by the genetic and embryological evidence.2 In a design view, however, homologies exist (at least in part) because new organisms need to be protected and nourished by organisms somewhat like them. But homologies need not be produced by similar genes or developmental pathways, since there is no insistence on the sort of mechanistic continuity required by Darwinian common descent.
In conclusion, a design perspective on the history of life might turn out to account for the biological evidence better than Darwinian evolution can. For example, Darwinism fails to specify why any given organism exists, beyond insisting that it be able to survive. But for design theory, a variety of creatures--including green plants and humanlike primates--are necessary prerequisites for human life. A design perspective requires progressive stages in the history of life, as seen in the fossil record, but unlike Darwin's theory it does not predict innumerable transitional forms that do not exist. Design theory also suggests that homologies exist, at least in part, so that certain organisms can prepare the way for others intended to follow them. Unlike Darwinism, it does not imply that homologous features are produced by similar genes or developmental pathways, and so does not run afoul of the evidence.
This analysis, although preliminary and subject to revision, demonstrates that a design perspective has major implications for our understanding of the biological evidence. As our knowledge of ecology and human physiology increases, and as the analysis is refined and expanded, more detailed implications will follow. In this way, a design perspective may eventually provide a detailed account of the history of life more faithful to the evidence than Darwin's theory and thus offer a framework for more fruitful research programs in biology.
1. See Unification Thought Institute, From Evolution Theory to a New Creation Theory: Errors in Darwinism and a Proposal From Unification Thought (Tokyo: Kogensha, 1996).
2. See Jonathan Wells, "Homology in Biology: A Problem for Naturalistic Science," presented at the Conference on Naturalism, Theism, and the Scientific Enterprise, Department of Philosophy, University of Texas, Austin, February 1997 (posted on the World Wide Web at http://www.dla.utexas.edu/depts/philosophy/faculty/koons/ntse/papers/Wells.html).