Text of Paper Presented at the Pontifical University of the Holy Cross, Rome, Italy, March 1,2 2001, IX Annual Conference, "God and Nature"

Martinez J. Hewlett, Ph.D.

Department of Molecular and Cellular Biology

University of Arizona

and

Southwest Regional Director

Science and Religion Course Program

Center for Theology and Natural Sciences

Tucson, Arizona

It has been over 140 years since Charles Darwin published "On the Origin of Species by Means of Natural Selection." The effect of this book was felt immediately in both scientific and lay circles. Within ten years of this publication, two other scientific events took place, neither of which would be noticed for more than fifty years. In 1868, Fr. Gregor Mendel reported on his experiments with pea plants, leading to his conclusions that heredity is quantitative and particular. In 1869, Frederich Meischer isolated a material he called nuclein from white blood cells. This biochemical constituent of the nucleus was DNA. Both of these latter discoveries would, eventually, have a major impact on the theory that Darwin had so clearly put forth in his book. The conjunction of these three 19^th century discoveries, seminal for the modern disciplines of evolutionary biology, genetics, and molecular biology, would come to form the neo-Darwinian synthesis that has dominated biology since the middle of the 20^th century.

The supposed conflict between science and religion is often cast, especially in the United States of America, as the extreme positions of scientific materialists on the one hand and creation science, Biblical literalists, on the other hand. However, the true nature of the conversation between the natural sciences and theology, between the work of God's hands and the mind of God, is rarely spoken of in academia.

First, it is my intent to explore the nature of evolutionary theory, examining some of the more important facts. I will then test the viability of two ideas, scientific materialism and intelligent design theory, that have fired much of the debate within both scientific and religious circles. Finally, I will offer a synthesis of positions, hopefully leading to a clearer appreciation of a God for evolution.

Darwin proposed that all living species descended from a common ancestor by a process of modification and selection. He used as some of the basis for his arguments the work of others, including his grandfather, the famed naturalist Erasmus Darwin. Most influential on this thinking were the critical observations he made during his voyage on the H.M.S. Beagle. Evidence of species variation that he collected, both in living species as well as from the fossil record, led him to his compelling conclusions.

John Maynard Smith has recently described Darwinian theory in a succinct manner. In his article, Smith points to four key features of Darwinian theory:

Notice that "survival of the fittest" does not entail competition per se. It may be that fitness has to do with the ability to obtain food in competition with other less fit members of the population. On the other hand, fitness may relate to survivability in a different, as yet unoccupied, ecological niche.

Darwin's problem in defending his theory was the lack of any understanding regarding the nature and source of the observed variations in populations. On what does the force of natural selection act? He had no answer for this question.

By the middle of the 20^th century an answer had been found. Variations in populations were seen as differences in the expression (phenotype) of versions (alleles) of genes (genotype). The force of natural selection acts on the collection of genes represented in a population.

Of course, differences in genes are described in molecular biological terms as differences in the sequence of base pairs that make up the DNA macromolecule. Such differences were shown in the 1940s to arise by mutation. Mutation is the alteration of a base pair by some physical or chemical change. For instance, the spontaneous loss of an amino group from a cytosine will convert this base into a uracil. If left unrepaired, this biochemical event may lead to a change in the information content of that particular region of a gene. If that change is reflected in the expressed product of the gene, we can say that the event led to a mutation. Such changes may also be the result of the collision of high energy particles such as cosmic rays or their secondary products with DNA. These events are ontologically unpredictable within the framework of quantum theory.

The quantum nature of these events leads to the idea of randomness in association with mutation. Of course, the result of the event is not random at all, but may take one of several pathways. A base cannot be changed into anything by the event, but only into a limited number of possible products. What is unpredictable is which base in a DNA sequence will be affected by a given event. This conjunction of randomness (chance) and law-like behavior (necessity) frames the very nature of the changes that underlie the evolutionary process.

It is also this interplay between law and chance that produces the novelty that is the central feature of the evolutionary record that has unfolded for us. Stephen Jay Gould's argument that, if the tape of evolution could be rewound and replayed from the beginning, it is unlikely that the same thing would be observed is a statement of the generation of novelty that is a part of this process. The history of life on our planet is a contingent one. It is the source of this novelty that has become contentious, as we shall see.

The modern statement of evolutionary theory, genetics, and molecular biology, the so-called neo-Darwinian synthesis, has come to dominate the landscape of the life sciences. The following hierarchical figure sets in place the organizational structure of modern biology.

Within this scheme are shown the various levels of organization that correspond to discipline-specific areas of concentration. At each level, there are contributing disciplines, such as chemistry and physics at the level of molecular biology, or atmospheric sciences and geography at the level of ecology. At every level, however, the twin paradigms of genetics and evolution are in force.

This organization is not simply the product of wishful thinking. Accumulating evidence from a variety of investigations at every level of biology support the notion that evolutionary theory is a reasonable representation of the physical history of the living world. Is this statement somehow at odds with theological reflection?

In the cacophony of voices rising to protest one view or the other in the evolutionary argument, it is often missed that 2000 years of church thinking has taken place. Let me recall the statements of three prominent theologians, separated not by conviction but merely by time.

St. Augustine, in his treatise "On the Literal Meaning of Genesis, wrote the following:

Was Augustine referring to Darwinian theory? Not at all, especially in light of descent from a common ancestor. Nonetheless, it is clear that this patristic reflection allows for an evolutionary perspective on creation.

Fast forward to the beginning of the second millennium and we find this comment by the Angelic Doctor himself:

Again, I do not mean to imply that in Question 69 St. Thomas was specifically referencing Darwinian processes. However, in recalling the earlier statement of Augustine, Aquinas was in agreement and added the reflection that creation continues to unfold even in the present.

Finally, in our day several theologians have commented on the status of evolution as a viable scientific idea, most recently Pope John Paul II:

The Holy Father here, with reference to the entire theological reflection of the Church, states once again in the 20^th century the conviction that evolutionary theory represents the most likely description of the physical developments witnessed in the scientific data.

If the theory of evolution presents no problem for the theologian, how then is it that the modern western crisis comes about? Enter the scientific materialists.

At the heart of scientific materialism is the reductionist stance that is more a feature of modern biology than it is of modern physics. To be clear, let me define reductionism as the process of explaining a phenomenon studied at one level of reality by the principles and processes understood at the level of the component parts of the phenomenon. In the normal pursuit of biology, methodological reduction is often used to allow the investigator to have a closer look at the molecular or cellular component of her choice. However, when the scientist becomes convinced of the epistemic exclusiveness of the reductive approach, and eventually of the ontological primacy of the material components of the living system at hand, the crossover is made into the philosophical position called scientific materialism. The scientific materialist states the sequence of the DNA determines all that there is to know about a living creature, be it amoeba or man. It is this metaphysical posture that allows Francis Crick to write:

Prominent among the current popular commentators in biology are Richard Dawkins and Daniel Dennett. One of Dawkins' most influential books is "The Blind Watchmaker," a titular comment on the work of Bishop Paley's early 19^th century natural theology.^, Dennett has also been well received with his book, "Darwin's Dangerous Idea." In each of these works, the tenets of scientific materialism dictate the authors' response to the facts of biological evolution as well as to the religious experience.

The central theme of their interpretation follows these guidelines:

In fact, as Dennett has been quoted as saying, the facts of biological evolution completely rule out the presence of God:

It would seem that reductionism has certain attractive features. After all, the power of the scientific method has led to the construction of the productive hierarchical organization shown earlier in Figure 1. But, let us examine this hierarchy in more detail.

If this ontological argument is correct, then every level must be explained completely by the principles in place at the level beneath it. Take, for example, the level of molecular biology and biochemistry. Biochemistry considers biological macromolecules as chemicals; whereas, molecular biology considers biological macromolecules as information. Can information be reduced completely to chemistry?

Michael Polanyi has suggested that this is not the case. In his critique of the reductionist approach, Polanyi argues that the information content of DNA is not, in fact, determined by the structure of the base pairs but rather by the content of the sequence. It is context, not chemistry, that is the key. In fact, it must be that the chemistry of the base pairs is indifferent to information. Otherwise, how could the same chemicals form the genetic plan for all living systems?

The neo-Darwinist position is also held by John Maynard Smith, quoted earlier with respect to his summation of Darwinian theory. In that text, from which the quote was taken, is a paper by Lynn Margulis, editor of the volume and originator of the endosymbiotic theory for the origin of organelles such as mitochondria. In that paper, the following table is found:

The changes that Dawkins, Dennett, and the other metaphysical reductionists argue are the sole feature of evolutionary variation are seen in the left column. However, there are other changes, some of them quite large scale and sudden in their occurrence. One of the most prominent is the proposed acquisition of energy generation by symbiosis that characterizes the emergence of eukaryotic cells. This sudden event appears to be echoed in the fossil record by a rapid radiation of these new cellular forms. This change cannot be accounted for by the gradualism to which Dawkins and Dennett appeal. It may, therefore, be concluded that strict adherence to the gradualist scenario is not essential for a neo-Darwinist.

Chaos and complexity theories offer new analytical tools for processes with as many variables as evolution. The idea that small changes in initial conditions will result in large variations in outcome seems to be an apt description of the evolutionary record. In this view, the properties of the whole are not simply the sum of the properties of the individual parts. Thus, the features of the whole are seen as emergent from the system represented by the individual parts. This argument can be used to explain concepts at all levels of biology, from information in macromolecules to speciation in populations.

How viable is this position? The major problem is that, for the committed scientific materialist such as Dawkins, an emergent property is considered an epiphenomenon. That is to say, information, for example, only appears to be something that emerges from the chemistry of DNA. In fact, he would argue, information can best be explained (epistemically) and is, in actuality (ontologically), the material form that makes up the DNA. This philosophical stance is not easily displaced by complexity analysis. Rather, this powerful tool is looked to for the way in which quantitative analysis of these massively interacting systems may eventually be carried out.

Both Richard Dawkins and Daniel Dennett argue for an evolutionary paradigm that is algorithmic. In "The Blind Watchmaker," Dawkins provides a computer program that allows the reader to watch the generation of "new" forms in a manner which he considers exactly analogous to biological evolution. In like manner, Dennett, in "Darwin's Dangerous Idea," argues for the inherently programmed nature of biological evolution.

If both of these scenarios are true, then the idea of novelty, such as seen in the analysis of the fossil record itself, is not really possible. After all, once one discovers the algorithm, then everything is inherently predictable and not novel at all. The extinction of the marvelously complex creatures whose history is told in the Burgess shale becomes just another "plug and chug" calculation. This contradiction does not seem to bother either of these commentators. Yet, the idea of a Darwinian evolution following in lock step even a complicated program seems at odds with the observed record of the events.

If the scientific materialist argument is weakened by these objections, what of the competing hypothesis?

Despite the warnings of St. Augustine some 1600 years ago, the literal interpretation of Genesis continues to form the opinions of many devout Christians. It is not this view, sometimes called scientific creationism, that I wish to discuss. I prefer to let St. Augustine teach us on this matter:

It is the more challenging idea of intelligent design that has captured the imagination of some within the academy as a way out of the dead end offered by the scientific materialists. The 19^th century version of this began with the publication of Bishop Paley's book on natural theology that has become the immediate target for Richard Dawkins evocative title. In our own age, the argument has been revisited in the compelling book, "Darwin's Black Box," by the biochemist Michael Behe.

Behe's argument, made from the position of an expert in the chemical machinery of cells, is that certain features of living systems are irreducibly complex. He uses the example of a mousetrap to make this point. He argues that a device as complex as a mousetrap must have all of its parts present in order for it to function effectively. If, for instance, the spring is missing, the presence of the bait will not result in catching a mouse. If the spring is present but the catch is missing, again the trap will not function. He then asks how it could be, in the Darwinian sense, that such a complex system could be selected by a process built on gradual, step-by-step changes, since, if any one part is missing, the function of the whole is not available as an object for selection. He, therefore, argues that such structures are irreducibly complex and must, as a result, be evidence of intelligent design. He then cites a number of examples from the biochemistry of cells, including the blood clotting cascade and the intracellular trafficking system of membranes.

St. Thomas' famous set of Aristotelian proofs for the existence of God, set out in the Summa Theologica included one often referred to as "the argument from design." In this fifth of his proofs, St. Thomas states:

In the argument of Behe, the irreducible complexity of the cell points towards the necessity for a designer of that cell. He states that the cell must have been designed directly by an intelligence and that all subsequent development followed the patterns explained by the Darwinian model. Was this what St. Thomas meant?

In the Summa Contra Gentiles, St. Thomas elaborates on the fifth proof to include a role for the providence of God in the governance of nature.

Thus, it does not seem to be a requirement of the Thomistic proof that God's action be in the direct design and construction of a primitive cell, from which all other cellular forms developed. In other words, cells may well have arisen within the laws of nature that are under Divine governance.

As I have already mentioned above, it is clear from the work of Margulis and others that the small, single base changes argued by Dawkins are not the only sources of variation in biological systems. The acquisition of energy generating organelles, among the other mega-hereditary changes shown in the table above, have clearly been major events in the history of life on our planet. Behe's argument is specifically directed at the gradualist, microhereditary changes championed by Dawkins and Dennett.

One example of how non-gradualist scenarios could be used as a method for the development of some of the complex systems to which Behe refers is the intracellular trafficking membrane system.

Using the endosymbiotic ideas of Lynn Margulis, Christopher Langton and I generated a model for the formation of the intracellular membrane system that characterizes eukaryotic cells. The figure below shows, in cartoon fashion, how this system might have arisen from a community of interacting cells.

In this scenario, the cells are sharing functions by living in community (Figure 2A). The colony has an increased survivability because of the shared functions. As a result, a closer association is selected for as a property of the colony(system) as a whole (Figure 2B). Eventually, the membranes of the colony members merge, so that what was once the intercellular space becomes the intracellular membrane system (Figure 2C and 2D). Sharing of functions between cells then becomes the method for moving materials inside the cell, the trafficking system. This feature of the cell, described by Behe as irreducibly complex, could arise by megahereditary chances within the scope of natural processes.

One of the inherent pitfalls of some natural theologies is the idea that scientific progress may, at some point, fill in the "gaps" that are often seen as the space within which God works. Imbedded within the intelligent design argument is just such a series of gaps. If it is shown that a series of events obeying the known natural laws could result in the same phenomenon, then God is displaced from the gap. I have already shown one such possibility above, in the model for the formation of intracellular membranes. Kenneth Miller also points out that, in the same year that Behe's book was published, work appeared in the scientific literature describing a reasonable way in which the blood clotting cascade might have arisen by Darwinian mechanisms. Does this mean that God does not exist? Of course not. It only means that the Intelligent Designer whom Behe argues directly built this complex system actually worked through the laws of nature that He established, rather than outside of them.

If God is not the being to whom the scientific materialists object or is not the micromanaging Designer of the complex systems argued by the intelligent design theorists, then where do we find Him?

The titles for this paper and for this section are taken from John Haught's book, "God after Darwin." What follows is an attempt to synthesize a view of theology that derives from this book, from the work of Kenneth Miller, and from the ideas of the cosmologist William Stoeger.

It is clear that when we speak of God's work in nature, we are speaking of two aspects of Divine action: creation (creatio ex nihilo) and continuing Divine action (called by some creatio continua). The first of these is obviously concerned with discussions surrounding the initial event (big bang cosmology, for instance). It is the second aspect of Divine action that seems to be relevant for discussions of biological evolution.

Now, St. Thomas, in his prologue to Question 65 in the Summa Theologica, distinguishes three kinds of activities for God: the work of creation, the work of distinction, and the work of embellishment (adornment). Logically, it is these later two that are most operative in what is called creatio continua. And, it is these aspects of Divine action that apply best to biological evolution. For it is distinction and embellishment that characterize the novelty seen in the biosphere.

The philosophical position of modern biology is decidedly reductionist and deterministic, almost in the sense of the Newtonian, pre-quantum period of physics. As a result, the intellectual framework of most biologists would allow, at best, a deist interpretation along the lines of God creating the initial laws and all else following according to the dictates of those laws. Any subsequent action of God, such as acts leading to novelty, would constitute a violation of those laws and an interference in the natural order of things. Thus, there would be no room within this framework for the Divine work of distinction and embellishment.

On the other hand, the maintenance of this philosophical position by modern biology seems unwarranted, especially since the revolutionary implications of the quantum view make clear the idea that the fundamental nature of the material universe is not deterministic but is indeterminate.

Many biologists still hold to the naïve realism of the 19^th century. I propose, instead, the more practical critical realist stance. The aim of biology (or any science) is to attempt the best description of a reality that exists. The success of this attempt varies, depending upon the tools and the paradigms that underlie those tools. In the words of Dr. William Stoeger:

The indeterminacy of nature opens the possibility for Divine action, both creative and distinctive. Many physicists and biologists will immediately argue that quantum indeterminacy is a phenomenon that applies only at the atomic and sub-atomic levels (leaving out the fact that the principles of quantum mechanics also seem to hold at the cosmic level). Is this truly the case? Can it be that quantum effects at the micro level have no reflection in events at the macro level?

We have seen that Darwinian processes act to select variants in the population of biological entities undergoing evolutionary change. These variants, in turn, arise, in the neo-Darwinian synthesis, by mutational changes in the DNA that encodes the blueprint of the entities. Such mutational changes are, in fact, quantum level events, subject to all of the phenomenology extant at that level of reality. Thus, it is not possible to predict (i.e., it is indeterminate) which base pair will be altered by interaction with a particular cosmic ray or cosmic ray by-product. And yet, it is this base change that will produce the phenotypic variation whose selection is at the heart of the evolutionary model. Thus, a quantum level, indeterminate event has an outcome reflected in the result of natural selection.

We might state, therefore, that the novelty we see in evolution, the distinguishing and embellishing Divine action, occurs through this indeterminacy. Stoeger has pointed out that this constitutes the veiled nature of reality and that it is behind this veil that God's actions may take place. Of course, this analogy begs for the critique of Bohm's hidden variables, wizards to be revealed once the curtain is withdrawn by the progress of science. On the contrary, in the standard interpretation of quantum mechanics, it must be that we cannot, in principle, see beyond the veil of indeterminacy.

For now, let us accept that Divine action is not disallowed in biology, if we revamp the philosophical underpinnings to include a critical 21^st century view of reality. Given that, how do we see God in all of this? And which God are we seeking?

Is it the God to which the scientific materialists object? This God is the figure in Genesis 1, taken literally by so many. Or is it the God to which the intelligent design theorists point? This is the "god of the gaps," or perhaps the Unmoved Mover. Which of these God's do we wish to encounter?

Again, St. Thomas reminds us that our ability to speak about God is limited. In fact, he devotes Question 13 in the Summa Theologica to this issue. He makes three main points:

Given this, we need to find some way of naming the ineffable that reflects the imperfect view we have of Divine action in biological evolution.

Of course, there are the notions of "pure essence" and "ground of all being" that state what God might be like. As important and central as these analogous statements are, such phrases do not seem to fire the soul in the same way that "King of Kings" does.

Perhaps, in seeking a God for evolution, we need to think about an analogy that relates directly to the distinguishing and embellishing nature of continued Divine action. In this sense, God as the generator of novelty, as the evocative force of evolutionary change would be an acceptable image. Or, it may be that the incompleteness of the evolutionary story is more to the biologists liking. In this way, God may be seen, as in our future. John Haught, quoting Teilhard de Chardin, reflects on a metaphysics of the future. God, he argues, is in our future, calling us along the journey that is both the evolution of the universe as well as our own personal quest. In this way, we and all creation are "groaning" towards the final end, the telos of creation.