Only A Theory

I was thinking of calling this blog entry “Germ Warfare”, because there are striking parallels between the science of evolution and the science of germs. For most of us living in the United States and Western Europe today, it is hard to imagine a time when people did not believe the germ theory of illness, and the fact that people not only did not understand that illnesses were caused by microbes of various sorts, but that they actively resisted the idea because it ran so contrary to what people had understood up until that point.

I am no expert on the history of our understanding of germs. But what little I know leads me to believe that it was one thing to persuade the scientific and medical experts, and something else to promote and publicize the understanding among the general populace so that it could benefit the health and well being of a whole society.

Evolution is in much the same situation. Among experts, the evidence is clear and overwhelming, and it comes not simply from an idea of Charles Darwin’s published 150 years ago, but from the combined information from genetics, paleontology, biology and many other fields. New evidence is constantly pouring in, and it consistently supports an evolutionary understanding. Through genetics, we now can be as certain about the degree of relatedness between organisms as we can about anything in science. Evolution allows predictions to made not just about where fossils with certain features should be found, but also about where to look for precious commodities like oil. And without evolution, we would not be able to combat diseases as effectively. Evolution can be witnessed in the lab. Contrary to the claims that are sometimes made, there is probably no other theory that has been tested as rigorously and been confirmed so consistently.

One way antievolutionists give the impression that evolution is “a theory in crisis” is by quoting experts out of context. I thought of this as I was reading Kenneth Miller’s wonderful book, Only a Theory: Evolution and the Battle for America’s Soul (New York: Penguin/Viking, 2008). At one point the reader encounters the following sentence (p.15): “ID is gaining support because it’s correct and because it provides a new explanation of life that supersedes Darwinian explanations.” It probably won’t be long until this quote is mined by supporters of ID. But to take it out of the context of a hypothetical “what if” line of argumentation turns it into a statement that runs counter to the argument of the book. But that is what proponents of ID do. They take bits and pieces and spin them in such a way that those who are unfamiliar with evolutionary theory get a very different impression than those who know and understand it and the overwhelming evidence that supports it.

Although some have suggested the book is a revision of his earlier Finding Darwin’s God, this is certainly not the case. The book is more of a sequel, focusing far more attention on Intelligent Design, the most recent developments in biology and in science education, and seeks to get at the heart of why evolution, a fabulous scientific success story, is nonetheless viewed negatively by an astounding number of Americans. The answer is of course that evolution has been set for them in contrast to meaning, value and purpose. Faced with such a choice, humans will always choose the latter. But as Miller points out (and as I’ve said many times on this blog), if evolution is a threat to meaning and purpose, then so are genetics, and embryology, and all the domains of science in which natural explanations of aspects of our existence are provided. The solution is to realize that we can be material, biological entities and valuable. We do this in other areas, and once the popular imagination does the same with biology, the antipathy towards evolution will begin to dissipate (see pp.141-143).

Miller’s book presents many examples of the evidence for evolution. The blood clotting mechanism in vertebrates is often cited as an example of a biological capacity that is “irreducibly complex” and thus “intelligently designed.” Yet possible stages in its development have been identified. Moreover, if we could go back in time and look at the ancestor of the vertebrates that have the blood clotting mechanism, we’d expect to find it had the raw materials to make such a mechanism already scattered around its genome. If we examine the sea squirt, a chordate that is descended from a common ancestor with modern vertebrates, we find all but two of the relevant proteins in its genome (p.66).

One amusing example of how creationists themselves provide evidence for evolution is provided on pp.92-95. While young-earth creationists regularly assert that the intermediate fossils between modern humans and earlier primates are either clealy human or clearly ape, if you compare how various creationists assess specific fossils, they differ on all but one of six major hominid fossils (see the chart on p.95). In other words, these authors agree in claiming that these fossils are clearly human or clearly ape, and yet cannot agree on which are which, thus providing evidence that these fossils in fact do not fall in an obvious way into one classification or the other.

Other examples abound, and are powerfully persuasive. Our loss of the ability to produce our own vitamin C suggests we had an ancestor that lived in a place where citrus fruit was in abundance and was part of the diet, and thus the ability to produce vitamin C could be lost without natural selection eliminating the error. What we find as we dig deeper is that we share this inability not only as humans but with those primates most closely related to us, but not others. We also share the same exact pseudogene in the beta-globin gene cluster as other primates, and as Miller points out, agreeing on errors is a classic example of decisive evidence for plagiarism (pp.99-101).

Miller’s book offers a passionate and persuasive vision of science as not incompatible with faith, while also showing how intelligent design is a danger to science. I highly recommend Miller’s latest book, like his earlier ones, to anyone interested in understanding evolution, or why pseudoscientific religiously-inspired movement gain the appeal that they do, and what exactly is wrong with them. Both science and faith are the stronger for the coherent vision of both Miller offers.

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  • Angie Van De Merwe

    Politics runs science, just as in any other realm of reality…Publications in major scientific journals are only published after “experts” review the information to be published. A major problem “happens” when the information to be published in a major journal challenges previous information published by well-known scientists, especially if they have political clout, which they usually do. This course of events limits the expansion of scientific knowledge to what is politically correct in major journals. That means that lesser journals may be publishing what is not politically correct. There is just too much scientific information and scientists are limited in “seeing the global scope of things” because of science’s specificity. There is enough information in one area of science to challenge any scientific mind. much less the other areas of science.Not only are the publications made by the “politics” of scientists, but, the interests of business also gets into the mix, when business interests (profit) are involved. Lobbyists are paid to make sure that certain monies are/not appropriated by the government for certain ends. And many times those ends are monetary and not for alleviation of disease. Because of the limitation of scientific knowledge due to “politics”, and because scientists have not, as a whole, interacted amongst the sciences to bring about “proof” on a larger scale, it is really hard to really affirm either theory. We have data, which we interpret as absolute, but the data is put into a framework or hypthesis to affirm or disconfirm a theory. Because science is based on observable data and then the data is assembled to affirm the theory, science is based on faith in what theory one believes in the first place. This is why when a major paradigm shift happens in science, it is intially not “accepted” because it challenges the assumptions of what is politically correct. This fact alone should dissuade any of us from being absolutely certain, as we are alway coming into understanding more fully. And it is only the open mind that can see something differently than previously concieved.

  • James F. McGrath

    There is no denying that science is not entirely immune from the influence of ideology, big business, bias, hoaxes, career interests and other such factors. That said, I remain unpersuaded that in our day and age, when the actual scientific data available is ever increasing, the situation in the natural sciences is the same as in the case of the Copernican revolution that so inspired Kuhn. The data is a harsh critic and science has excellent methods in place that require one’s work be submitted to the harsh examination of reality. If science cannot claim to be above all bias, it certainly has a greater capacity to avoid such manipulation than most other domains of human inquiry.And when it comes to evolution, the mass of data that all points in a single direction is impressive.The greatest irony, in fact, in the “creation wars” is the way the modernist fundamentalists have themselves utilized and manipulated the rhetoric of relatism that they dislike just as much as evolution, to use as a weapon against one of the most critically tested and impressively vindicated scientific theories of all time.

  • sarah

    I recently came across your blog and have been reading along. I thought I would leave my first comment. I don’t know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often. Sarah

  • James F. McGrath

    Thanks for your kind comment!

  • newenglandsun

    When I quote something in a research paper, I try to find the context of the quote to make sure the snid-bit part that I’m quoting is in harmony with the author’s point. I have that book and I think that the strength in Kenneth Miller’s approach is that he thinks the intelligent design side should be looked into and tested for validity.