The science-religion front is the site of ongoing conflict. On the one side are the militant atheists like Oxford-based biologist Richard Dawkins, who want simply to remove religion from the face of the earth. On the other side are the Bible-touting evangelicals like Intelligent-Design-enthusiast and Lehigh University biochemist Michael Behe, who want to supplement science with direct divine interventions. Caught somewhat uneasily in the middle, arguing that you can have both science and religion, are the so-called "accommodationists" like UC Irvine geneticist and recent winner of the Templeton prize in religion, Francisco Ayala.
It is indisputable that there can be conflict between science and religion. You cannot consistently hold to Darwinian evolutionary theory and be a Young Earth Creationist, thinking that the earth and its denizens were created in six days, 6,000 years ago. But the reply by accommodationists (I am one) is that traditional religion (let us stay with Western Christianity for simplicity of discussion) has always had within it the means to take claims metaphorically if there is a possible clash between science and religion. Saint Augustine in 400AD told us that we should not take the early chapters of Genesis too literally.
About 10 years ago I wrote a book called Can a Darwinian Be a Christian? Answering my question, I argued that it is not easy, but it is possible. Interestingly, I found that some of the things that I thought would be major stumbling blocks, specifically the problems of miracles and of evil, were not as great as feared. I am not saying that the problems of miracles and of evil can be solved. For myself, I just don't see how one can reconcile Auschwitz with an all-loving, all-powerful God. But I didn't think that Darwinism exacerbated the problem, and in respects I thought it positively helpful. (I know that one of the worst things one can say at a point like this is: read my book to find why I say what I do. But, candidly, read my book to find why I say what I do! If you have to buy it, the next time we meet I will buy you a beer.)
To my great surprise, however, I found what I thought then and still think now a major problem with reconciling Darwinism with Christianity. It is an absolute bottom-line claim of the Christian that the existence of humans is not contingent -- if we did not exist then the Christian story could not be. It might be that we are blue and that we have twelve fingers. Possibly, although I am not sure, it might be that we don't have sex. But intelligent beings, with moral awareness, able to act in this world, have to exist if Christianity is true. Otherwise, what is the point of all of that stuff about being made in "His Image"? However, Darwinism stresses that change is random and non-directed. For Darwin and his followers this has always been an absolute. Obviously humans are pretty complex animals, but our arrival has always been in some sense a matter of chance. From a notebook of Darwin, written early in 1839 just after he had discovered his mechanism of natural selection:
The enormous number of animals in the world depends of their varied structure & complexity. -- hence as the forms became complicated, they opened fresh means of adding to their complexity. -- but yet there is no necessary tendency in the simple animals to become complicated although all perhaps will have done so from the new relations caused by the advancing complexity of others.
Today's Darwinians would make the case for non-directionality on two grounds. First, natural selection is always opportunistic, relative. What works in one case might not work in another. There are no absolutes, no fixed goals. Humans are pretty good organisms, but they have their drawbacks. For a start, their brains need massive amounts of protein, usually dead animals. There was no guarantee in the wild that such protein was always available or that we might not have been better eating grass albeit a bit dumb. Buffalo were doing pretty well until humans turned up. For a second, the building blocks of evolution, the mutations, are random, not in the sense of being without cause, but without regard for what their possessors need. Things can go any which way.
I have been thinking again about these issue thanks to an excellent new book authored by two Duke professors, biologist Daniel McShea and philosopher Robert Brandon. In Biology's First Law: The Tendency for Diversity and Complexity to Increase in Evolutionary Systems, they argue that irrespective of natural selection, organisms are going to get more and more complex. This is going to happen as a matter of chance rather than design. (They admit that this puts them more in line with the Victorian general man of science Herbert Spencer than Charles Darwin.) Defining something to which they have given the rather ugly name of Zero-Force Evolutionary Law (ZFEL) -- but after Punctuated Equilibrium, who is to complain about ugly names in biology? -- they write: "In any evolutionary system in which there is variation and heredity, in the absence of natural selection, other forces, and constraints acting on diversity or complexity, diversity and complexity will increase on average."
No doubt philosophers and biologists will be poring over this claim. I hope that those of us on the science-religion interface will do so also, although frankly my initial sense is that it will not provide what is needed. The authors are not talking about the evolution of value or excellence, and there will be all sorts of questions about whether humans are the most complex organisms that have evolved or could evolve and so forth. The authors define complexity somewhat austerely as "the amount of differentiation among parts in an individual" and it seems to me an empirical matter where humans stand with respect to this. One thing I would note that is that in respects the human genome seems a lot simpler than once thought -- far fewer genes, for instance.
The trouble is that I am not sure that there are any other scientific solutions around at the moment that solve the non-directionality problem. Richard Dawkins thinks that overall evolution shows direction, leading to human-like creatures, because of biological arms races -- lines of organisms complete and adaptations get better. The gazelle gets faster and the lion gets faster. But although Dawkins thinks that ultimately this will lead to organisms with big on-board computers, a.k.a. human brains, I am not sure that this necessarily follows. If things had gone other ways, I don't see why we shouldn't have all ended up as very efficient, grass-consuming buffaloes. Cambridge paleontologist Simon Conway-Morris thinks that there are ecological niches waiting out there to be occupied, and eventually someone would have entered the brain-culture niche as did humans. But whether niches do exist in isolation like that is debatable, and why it had to be that the human niche did necessarily get occupied seems to me to be another matter.
You could of course adopt some kind of God-directed evolution, as did Darwin's great American friend, the Harvard botanist Asa Gray. This is the position of California physicist-theologian Robert John Russell. He argues that God directs mutations down at the quantum level, where we can never enter. But frankly this seems to me to be at total variance with the spirit of modern Darwinism. My suspicion is that if the problem is to be solved, then it has to be done with a theological solution rather than a scientific one. You need to argue from the side of Christianity rather than from the side of Darwinism. My own inclination is to invoke some variant of the multiverse hypothesis -- many different universes -- but to do this on theological grounds (if God wants to He can) rather than scientific grounds. Since humans did evolve, they could evolve (through Darwinism). It was just a matter of God giving it enough shots and it would happen. This seems awfully wasteful, but then as the nineteenth-century English historian and philosopher of science William Whewell worried, this universe with its vast expanses seems awfully wasteful anyway. Who are we to say that God thinks a non-human-occupied world is going to waste?
I am not sure that this is a satisfactory solution, but McShea and Brandon's stimulating new book, Biology's First Law, moves me to say that those of us working on the science-religion interface and who think that the two can be reconciled need to keep up the search for a satisfactory solution to the puzzle of the necessity of humans and the non-directionality of Darwinism.