Molecular Biology and the New Creationism?1
The decision in the Dover creationism trial last month probably came as a relief to most biologists worried about the status of our science in the nationâ€™s high schools. Unimpressed by the arguments of renegade biochemists such as Michael Behe, a judge ruled that â€œID [Intelligent Design] is a religious view, a mere re-labeling of creationism, and not a scientific theory.â€?2 The judge was equally correct in holding that the ID creationistsâ€™ arguments were old, in fact going back to William Paleyâ€™s argument from design from the early nineteenth century. But one aspect of the dispute has changed, in fact changed radically from even twenty years ago, when Scientific Creationism rather than Intelligent Design was on trial.3 All of Intelligent Designâ€™s examples and arguments are molecular. There are two questions lurking here. Why have the creationists gone molecular? And what can we expect from them in the future, given that genomics is revealing more and more complex detail about the organization and behavior of genomes? We should think about these questions seriously because, in spite of this defeat, these well-funded creationists4 are not about to go away.
That the ID creationists have focused on the molecular level initially seems really surprising. After all, the area where evolutionary biology still has much to do is the evolution of morphological form, animal body-plans, why all animals have either bilateral or five-fold symmetry, and nothing else, etc. This is where the new science of evolutionary developmental (â€œevodevoâ€?) biology shows most promise but is yet far from mature.5 (Some creationists, for instance, the Discovery Instituteâ€™s Stephen Meyer do harp on animal form, and the problem posed by the Cambrian â€œexplosion,â€? but these are relatively rare. The Dover judgment makes no reference to this question.)
Instead, ID creationists focus on structures such as the bacterial flagellum or processes such as blood clotting which are supposed to be â€œirreducibly complexâ€? in the sense that simpler things with fewer parts cannot have perform the relevant function. In each case, biologists have shown that the examples donâ€™t work6 (as the judge in the Dover case duly noted) but thatâ€™s not what is at stake here. What is at stake is what the molecules are doing for creationists that larger structures cannot do. After all, molecular evolution is not that mysterious and, because protein and genome sequence data are accumulating so rapidly, using extensive molecular homologies, puzzles are being resolved more rapidly here than in other areas of evolutionary biology.
Well, there seem to be four ways in which the molecular level is welcoming to creationists. First, concentrating on complex molecular structures within cells, fine tuned for performance by billions of years of selection, seems to force us to have to explain the origin of the cells, that is, of life itself, a problem which we cannot yet fully solve. Creationists like to use this lacuna to cast doubts on evolutionary theory as a whole7 as if how life originated necessarily bears on how living forms have evolved afterwards. Second, ID creationists like to present all their concerns as ones about the origin of biological information which is easier to do in the molecular context because we typicall use informational concepts there. Their argument is that evolution could not have generated biological information, or it could not have generated this much biological information, or that it could not have generated this type of biological information (the sands keep shifting8). This argument relies on the work of Bill Dembski9 which is known to be mathematically flawed.10 The creationistsâ€™ cause is inadvertently aided by some older information theorists who have also expressed bewilderment over the evolution of information. It is high time that we had sustained discussion of the utility of informational metaphors in biology (on which there is considerable skepticism12) as well as the evolution of information (on which there is already some good work13).
Third, creationists have an easier time convincing molecular biologists (rather than, say, organismic biologists) that there are problems with evolutionary theory simply because molecular biologists, at least in the United States, typically do not have a serious background in evolutionary biology. In particular they are often unaware of the mathematical subtleties of models of population genetics, what they do and do not allow. For instance, how many molecular biologists know that, if selection is occurring on a trait controlled by two genes (loci) located on the same chromosome (there is linkage), natural selection does not always increase the mean fitness of the population? It seems almost self-contradictory but is a mathematical result that undercuts many creationist arguments about optimization.14 Fourth, with some justice, the public regards molecular biologyâ€”and, these days, much of it is genomicsâ€”as cutting edge science. So, by engaging molecular biology, creationists like Behe can pretend to work at the frontiers of science while evolutionary biologists are presented as old-fashioned naturalists following a 19th-century icon called Darwin.
Turning to the postgenomic situation, we have a potential problem. The organization and behavior of the genome has dealt many surprises, for instance, a lack of correlation between genome size and organismic complexity, massive alternative splicing of RNA in many species, the uneven organization of the human genome. For these, at least, we have some evolutionary stories (though they are no more than stories at this stage).15 For other features, we have no convincing story at all, for instance why so much RNA (apparently from what was once believed to be junk DNA) is transcribed in cells.16 This is not unreasonable: evolutionary stories should always be constructed carefully and this takes time. But molecular biologists are doing even less now than what they once did. For instance, when introns were first discovered in 1978, Walter Gilbert immediately published a speculative piece, â€œWhy Genes in Pieces?â€?17 that turned out to contain several worthwhile insights. We should confront the genome similarly but also construct detailed evolutionary models since verbal models in evolutionary biology are always subject to the objection that they are â€œjust soâ€? stories. We have work to do.
To face future creationist challenges, three important items belong on our agenda: (i) explicit discussion of biological â€œinformationâ€? and what we can say about its origin and evolution; (ii) explicit discussion of evolutionary scenarios for the complexities of genomic organization and behavior as they emergeâ€”in both cases, verbal arguments must be augmented by quantitative models, simulations, and other mathematical work; and (iii) a systematic integration of evolutionary biology into the education of all molecular biologists. Or we may end up with creationists in our own back yard.
1 Â© 2006 Sahotra Sarkar; published 2006.
2 See: http://www.pamd.uscourts.gov/kitzmiller/kitzmiller_342.pdf, p. 43; accessed 25 December 2005.
3 See Kitcher, P. 1982. Abusing Science: The Case Against Creationism. Cambridge, MA: MIT Press.
4 Forrest, B. and Gross, P. R. 2004. Creationism’s Trojan Horse: The Wedge of Intelligent Design. New York: Oxford University Press.
5 Carroll, S. B. 2005. Endless Forms Most Beautiful: The New Science of EvoDevo and the Making of the Animal Kingdom. New York: W. W. Norton.
6 Miller, K. R. 1999. Finding Darwin’s God: A Scientist’s Search for Common Ground Between God and Evolution. New York: Cliff Street Books.
7 See, for example, Dembski, W. A. 1998 â€œThe Act of Creation: Bridging Transcendence and Immanenceâ€? [http://www.leaderu.com/offices/dembski/docs/bd-the_ac.html]; accessed 25 December 2005.
8 All three versions are to be found in: Dembski, W. A. 2002. No Free Lunch: Why Specified Complexity Cannot be Purchased without Intelligence. Lanham, MD: Rowman and Littlefield.
9 Dembski, W. A. 2002. No Free Lunch: Why Specified Complexity Cannot be Purchased without Intelligence. Lanham, MD: Rowman and Littlefield.
10 See Wolpert, D. H. 2003. â€œWilliam Dembski’s Treatment of the No Free Lunch Theorems is Written in Jelloâ€? [http://www.talkreason.org/articles/jello.cfm] accessed 25 December 2005; Shallit, J. and Elsberry, W. R. 2004. â€œPlaying Games with Probability: Dembski’s Complex Specified Information.â€? In Young, M. and Edis, T., (ed.), Why Intelligent Design Fails: A Scientific Critique of the New Creationism. New Brunswick: Rutgers University Press, pp. 121 -138.
11 For instance, Yockey, H. P. 2005. Information Theory, Evolution, and The Origin of Life. Cambridge, UK: Cambridge University Press.
12 Sarkar, S. 1996. â€œBiological Information: A Skeptical Look at Some Central Dogmas of Molecular Biology.â€? In Sarkar, S., (ed.), The Philosophy and History of Molecular Biology: New Perspectives. Dordrecht: Kluwer, pp. 187 -231.
13 Schneider, T. D. 2000. â€œEvolution of Biological Information.â€? Nucleic Acids Research 28: 2794 -2799.
14 Moran, P. A. P. 1964. â€œOn the Nonexistence of Adaptive Topographies.â€? Annals of Human Genetics 27: 383 â€“ 393.
15 Sarkar, S. 2005. Molecular Models of Life: Philosophical Papers on Molecular Biology. Cambridge, MA: MIT Press, Chapter 14.
16 See, however, Mattick, J. S. 2003. â€œChallenging the Dogma: the Hidden Layer of Non-Protein-Coding RNAs in Complex Organisms.â€? BioEssays 25: 930 -939; Mattick, J. S. 2004. â€œThe Hidden Genetic Program of Complex Organisms.â€? Scientific American 291: 60 -67.
17 Gilbert, W. 1978. â€œWhy Genes in Pieces?â€? Nature 271: 501.