The theory of biological evolution is widely acknowledged in the scientific community as the great unifying theory in biology. Evolutionary biologist Ernst Mayr writes:
The theory of evolution is quite rightly called the greatest unifying theory in biology. The diversity of organisms, similarities and differences between kinds of organisms, patterns of distribution and behavior, adaptation and interaction, all this was merely a bewildering chaos of facts until given meaning by the evolutionary theory. There is no area of biology in which that theory has not served as an ordering principle (Animal Species and Evolution).
The neo-Darwinian synthesis, the version of evolutionary theory that arose in the 1940′s, brought together taxonomists, ecologists, and geneticists with the recognition of the importance of geography and population biology in evolutionary change. Consequently, among all branches of biology evolutionary theory commands nearly universal acceptance. Not only does evolutionary theory organize the various branches of biology, but each of them contribute somewhat independently to a unified coherent theory. Paleontology, classical and molecular genetics, population biology, sociobiology, taxonomy, developmental biology and biochemistry have joined together to contribute to the grand universally accepted synthesis. This is not to say that these contributors do not argue among themselves concerning the relative weight and interpretation of their respective contributions, but these are in-house discussions. Among professional biologists evolutionary theory is considered not only the best explanation of the available data, but a very good explanation of that data.
Of course, universal acceptance of a theory does not necessarily mean that it is correct or even that those who accept it accept it on the basis of the empirical evidence. Critics of evolutionary theory often claim that a deeply rooted religious commitment to atheistic naturalism drives most of the scientific community to accept evolution. In other words, evolution (together with big bang theory, chemical evolution, plate tectonics and other geological theories) is part of a “religious” origins account for the atheistic naturalist. Recent criticisms along these lines include those by Phillip Johnson (Darwin on Trial) and Alvin Plantinga (Christian Scholar’s Review, Special Issue: Creation/Evolution and Faith, “When Faith and Reason Clash: Evolution and the Bible” and responses). There is no doubt that some evolutionists, especially those who write for a more general audience, have used evolutionary theory to support their atheistic views. Perhaps the most celebrated example of this is the widely quoted statement of Richard Dawkins (author of The Blind Watchmaker) “Although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist.” Plantinga claims that given atheism, evolution is a warranted theory, but that given theism (which all Christian would admit), the empirical evidence for evolution is not compelling and that some sort of special creationism seems more likely. Plantinga seems ready to admit to some of the evolutionary claims, but believes that at key junctures in the theory (e.g. origin of life, the pre-Cambrian explosion, origin of human beings, and perhaps other sudden appearances of new forms) that a more warranted explanation, given theism, is to call upon some act of special creation.
In principle, I sympathize with the claims of Plantinga and Johnson. Certainly, some evolutionists use this biological theory to buttress their atheistic worldview and Christian scholars are called upon to point out this use of evolutionary theory. Also, the atheist, who has no origins alternative, has much at stake, morally and existentially, in denying God a role in creation. Christian scientists must be cognizant of these non-scientific factors at work in the theorizing that occurs in the professional community. However, having said this, I do not agree with Plantinga in his claim that, given theism, the warrant for evolution is weak. It is my judgment, as a biologist and as a theist, that the evidence for evolution is strong and that it something that the Christian community needs to wrestle with. It is interesting to note, without getting into all the historical nuances, that Darwin left England on the Beagleas a theist with special creationist leanings (like most of his contemporaries) and that it was his observations of the natural world, especially in the tropics, that led him to his evolutionary views.
The theory of biological evolution does not necessarily imply the atheistic worldview described above. In fact at several key junctures I must disagree with many of the advocates of evolution. In doing so they may even claim that I am not an evolutionist at all, but that is a conclusion that they and not one that I make. The heart of this disavowal has to do with the claim that although I accept evolution as a biological theory, I am still a Creationist. The biological theory is our human formulation (subject to on-going refinement) of God-governed “natural” processes whereby God created the vast array of living things. The word “natural” is used not in the sense of “autonomous” but in the sense of “regular” or “ordinary”. The notion of secondary cause captures the idea. God is the ultimate governor, yet He choose to govern process via regular cause and effect relations that can be understood as we observe the world. This can and should be said of every natural occurring process that can be described by science.
There are several implications of this theistic view of evolution. Since the term “theistic evolution” seems to be suspect for some reason, perhaps we should call it an “evolutionary creation”. This semantic shift makes creation the noun rather than evolution, perhaps for the better. The evolution that I hold to is not random in any ultimate sense, nor is it purposeless, nor is it without design. These are all claims that some evolutionists make. But these are metaphysical and theological claims, not scientific claims. There is a certain sense in which I believe that chance or random processes are involved in mutation or chromosome rearrangements or in recombination or chromosome pairing during meiosis or gamete fusion. These processes are empirically known to follow the laws of statistics, just as coin flipping, card drawing, or sex determination does. But this is not to say that these processes are chance or random in any ultimate sense. Since God is the ultimate governor of whatsoever comes to pass, each coin flip, card draw, or mutation is determined by his all-wise and all-holy counsel. There is even a Proverb (16:33) that says “The lot is cast into the lap, but its every decision is from the Lord.” Design and purpose can be discussed in the same way. Just because adaptations (the excellent fit between an organism’s structure and function or environment) can be accounted for by natural selection, does not mean that there is not a divine design or purpose. That claim is fundamentally religious and atheistic. There is no necessary incompatibility between evolution by natural selection and divine design and purpose.
I can think of no better way to support my point here than by quoting from A.A. Hodge, the Old Princeton theologian whose commitment to the inerrancy and authority of Scripture and to the Reformed faith is beyond question. Hodge wrote the following in the Introduction to Theism and Evolution by Joseph S. Van Dyke and reprinted in The Princeton Theology 1812-1921 edited and compiled by Mark Noll (Presbyterian and Reformed, 1983):
Evolution considered as the plan of an infinitely wise Person and executed under the control of His everywhere present energies can never be irreligious; can never exclude design, providence, grace, or miracles. Hence we repeat that what Christians have cause to consider with apprehension is not evolution as a working hypothesis of science dealing with facts, but evolution as a philosophical speculation professing to account for the origin, causes, and end of all things.
Hodge’s colleague and contemporary at Princeton, B. B. Warfield, wrote the following in his unpublished “Lectures on Anthropology” (Dec. 1888) (cited in Darwin’s Forgotten Defenders, p. 119):
The upshot of the whole matter is that there is no necessary antagonism of Christianity to evolution, provided that we do not hold to too extreme a form of evolution. To adopt any form that does not permit God freely to work apart from law and which does not allow miraculous intervention (in the giving of the soul, in creating Eve, etc.) will entail a great reconstruction of Christian doctrine, and a very great lowering of the detailed authority of the Bible. But if we condition the theory by allowing the constant oversight of God in the whole process, and his occasional supernatural interference for the production of new beginnings by an actual output of creative force, producing something new i.e., something not included even in posse in the preceding conditions, we may hold to the modified theory of evolution and be Christians in the ordinary orthodox sense.
The lengthy citation of Abraham Kuyper (cited in Creation and Evolution by Jan Lever) is worth repeating here to express the notion that evolutionary theory is not necessarily antagonistic to the Christian faith if design and
purpose are not excluded.
An entirely different problem is that so often discussed in England whether religion permits, as such, the spontaneous evolvement of the species in the organic world from one single primary cell. That question, of course, without reservation, must be answered in the affirmative. We should not impose our style upon the Chief Architect of the universe. (emphasis mine) Provided he remains, not in appearance, but in essence, the Architect, he is also in the choice of his style of architecture the Omnipotent. If it thus had pleased the Lord not to create the species as such, but to have one species arise from the other, by designing the preceding species in such a way that it could produce the next higher, the creation would have been just as wonderful. But this never would have been the evolution of Darwinism because the predetermined plan would not then have been excluded, but would have been all predominating, and not the world had then built itself up mechanically, but God by means of elements which He himself prepared for that purpose. The contrast shows itself most clearly from an illustration selected by Haeckel. In order to remove the objection that is inherent in the mechanical explanation of a complex organism, he asks whether a Zulu Negro, who at Lorenzo Marquez sees an English armored battleship enter, would not certainly view this colossus as an organic monster, while we, of course, know very well that it has been riveted together mechanically. Everyone naturally agrees with this. But Haeckel overlooked the fact that in the shipyard the steel plates did not place themselves in the proper position, but that they have been put together by a skillful architect according to a previously prepared plan. And that same difference would differentiate such a divine evolutionistic creation from the system of the Darwinists. Evolutionistic creation presupposes a God who has first made the plan and then executes it omnipotently. Darwinism teaches the mechanical origin of things that excludes all plan or purpose or draft. The acceptance of evolutionary theory by Christians must be seen as mediate Creation, whereby God called some things into existence using pre-existing materials and ordinary means. As indicated by the above citations, these orthodox Presbyterian and Reformed theologians, found no reason to disagree with evolutionary theory as long as the certain essential characteristics were not disregarded: the dependence of the Creation on God, His design and purpose, the Creation of human beings in God’s image, and God’s freedom to act miraculously in his Creation.
An additional issue is whether or not evolutionary theory comports with specific teachings of scripture concerning the creation of all things. The days of Genesis 1 and the specific account of the creation of Adam and Eve have been particular sources of difficulty. In the orthodox Reformed tradition dating from at least the middle of the 19th century, the days of Genesis 1 have been regarded as long periods of time or as a literary framework for the execution of God’s creative decrees. My own view is the latter. Reconciling evolutionary theory with the specifics of the Genesis 2 account of the creation of Adam and Eve is much more difficult. The text of Genesis 2:7 does not appear to allow for the view that the body of Adam derived from animal ancestors. How this squares away with evidence from the created world suggesting others is still an unanswered question in my mind. Clearly, the creation of Adam as a whole human being, body and soul, in the image of God, was the result of a special miraculous act. Also, the creation of Eve as derivative from Adam was the result of a special miraculous act. This conclusion about the origin of man derives primarily from the text itself. If the text were silent on this matter, I would have no problems with a Divinely guided evolutionary origin of the first human beings.