GENEWATCH
 
BAD SCIENCE: GENETICS, AS MISREAD BY CREATIONISM
By Glenn Branch
 

from GeneWatch 26-4
Aug-Oct 2013

Genetics is satisfyingly concrete. The genotypes rolling inexorably from the Punnett square; the millions of miles of DNA curling tidily within the cell nuclei of every human body; the reams of hard data spooling out of genome project after genome project: these suggest a sense of stern factuality. Evolution, however, offers a view of life extending through unimaginable eons, with infinitesimal changes eventually amounting to important differences. The result is a tree of life that challenges plausibility: eucalyptus shares a common ancestry not only with yew but also with you.

In truth, there's plenty that's counterintuitive about genetics, and there's plenty that's commonsensical about evolution. Moreover, evolution and genetics are "two very closely interwoven disciplines," as the Genetics Society of America observes, so it is difficult to disentangle the two from each other or from the fabric of biology as a whole.[1] Still, relying on a general trust in genetics and a general ignorance of, skepticism about, or hostility toward evolution, creationists regularly attempt to misrepresent genetics - whether the population genetics of the middle twentieth century, the molecular genetics of the late twentieth century, or the genomics of the early twenty-first century - as posing a problem for evolution.

At bottom, creationism is the rejection of evolution, the idea of common descent, and allied scientific principles in favor of supernatural creation. (Believing that God is, in the words of the Nicene Creed, "maker of heaven and earth, and of all that is, seen or unseen," is insufficient; it's necessary also to reject evolution.) As such, creationism comes in different varieties, depending on differences in the supernatural creation account offered. The most familiar forms of creationism are based on the Christian Bible, but Jewish, Islamic, Hindu, and even Native American and New Age forms are to be found. Within Christian creationism, the main division is between young-earth creationists, who hold that the world is merely thousands of years old and tend to accept Noah's Flood as historical and worldwide, and old-earth creationists, who accept the scientifically ascertained age of the earth and tend to reject the universality of Noah's Flood. Intelligent design, so-called, is not so much a distinctive form of creationism as it is a strategy for promoting it within the confines of American constitutional law: by remaining silent about the identity of the designer, its proponents hoped for proposals to teach generic creationism in the public schools to survive judicial scrutiny.[2]

Historically, three goals have characterized the creationist movement in the United States: banning the teaching of evolution; balancing the teaching of evolution with the teaching of the supposed alternatives of biblical creationism, creation science, or intelligent design; and belittling evolution as "just a theory" or as "controversial." Banning the teaching of evolution was popular during the 1920s, with the Scopes trial as the famous consequence, but the tactic was ended with a Supreme Court decision in 1968. Balancing the teaching of evolution became a major tactic in the wake of the 1968 decision, but each supposed alternative faltered with court decisions, biblical creationism in 1975, creation science in 1982 and 1987, and intelligent design in 2005. Thus, although belittling evolution is a long-standing tactic, it recently became preferred and prominent, with laws enacted in Louisiana in 2008 and Tennessee in 2012 that encourage teachers to misrepresent evolution as controversial. Throughout, three rhetorical themes have been constant: that evolution is bad science; that teaching evolution is connected to religious, moral, and social problems; and that alternatives or objections to evolution ought to be presented for the sake of fairness.[3] It is primarily in the first of these contexts that creationists have abused genetics.

The idea that genetics favors creationism over evolution comes in versions ranging from the silly to the sophisticated. At the silly end of the spectrum is the notion that evolution is debunked by the fact that organisms as different as the opossum and the giant sequoia have the same number of chromosomes. Misconceptions about mutations - that they are rare; that they are inevitably detrimental; that they are incapable of producing novel features, even when repeatedly winnowed by selection - are ensconced in the creationist mainstream, where they form the basis of arguments that evolution is impossible (except within so-called biblical kinds). Sometimes these are ornamented with specious claims about genetic information. At the sophisticated end of the spectrum are the contentions of creationists who have pounced on recent claims in the scientific literature that more than eighty percent of the human genome is functional, inferring that such a high degree of function bespeaks design. These claims have been challenged in the scientific literature as involving a dubious notion of functionality.[4] But whether or not the claims survive scientific scrutiny, the creationist inference to design - reminiscent of William Paley's 1802 blockbuster Natural Theology, and possessing all of its scientific rigor - is anything but scientifically compelling.

Genetics is also abused in the service of claiming that evolution is, if not inferior to creationism, at least controversial. A recent example was provided in Kentucky, where public comments were offered about the Next Generation Science Standards, under consideration at the time for adoption in the state. Based on a framework formulated by the National Research Council, the standards treat evolution as a unifying idea of the life sciences. According to a summary of the comments, "A commenter stated there are non-religious objections to evolution, and cited [...] Moeller [sic] and Newman, epigenetics, the work of the Altenberg 16, [...] and others."[5] The commenter was apparently referring to scientific work seeking to incorporate new ideas about genetics within evolutionary biology.[6] But such work is at the frontier of scientific thought; it is not appropriate for inclusion in state science education standards. More importantly, none of these scientists would describe their work as providing "objections to evolution." The editors of the proceedings of the Altenberg symposium, for example, conclude the introduction to their volume by commenting, "150 years after the publication of the Origin of Species, evolutionary theory is still making enormous progress in its capacity to explain the world we live in."[7]

Ironically, while creationists abuse genetics to argue against evolution, they also argue against evolution by holding it responsible for the abuses of genetics, particularly eugenics, the program of improving the genetic composition of the human population. Tainted by its coercive implementation, particularly in Nazi Germany, eugenics has a bad odor today, and creationists are eager to blame its historical excesses on evolution. But eugenics is historically and conceptually separable from evolution. After all, Plato's Republic argued for selective breeding of humanity two millennia before Darwin's Origin. In its modern heyday, eugenics was supported on scientific and extrascientific grounds not connected to evolution. For instance, it was often promoted by clergy and churches that were not notably invested in evolution, and even by card-carrying creationists such as William J. Tinkle.[8] Moreover, eugenics in its heyday was based on a variety of claims about heredity that are no longer accepted; there is hardly any risk that teaching evolution will encourage students to accept eugenics. Finally, it is uncontroversial that science education in general needs to distinguish scientific issues from policy issues, is from ought. Students who are properly taught about evolution aren't being offered any recommendations about social policy.

Even though creationists are fond of citing the failure of Charles Darwin's own theory of heredity and of quoting Alfred Russel Wallace's verdict on "the general relation of Mendelism to Evolution" - that the former "is really antagonistic to such evolution"[9] - there's never been a time when it made scientific sense to talk about evolution and genetics as opposed. True, there have been occasional tensions and conflicts between the dominant theories of evolution and the dominant theories of genetics. Most famous is the clash between Mendelians and biometricians, which began to be reconciled by the foundation of population genetics by J. B. S. Haldane, Ronald Fisher, and Sewall Wright, and was finally resolved by the establishment of the Modern Synthesis by Theodosius Dobzhansky, Ernst Mayr, and G. G. Simpson. As both evolution and genetics continue to advance, such tensions and conflicts are likely to continue - and also to continue to be exploited by creationists. But the scientific community firmly agrees with the evolutionary biologists Brian Charlesworth and Deborah Charlesworth about the "value of the ongoing interaction between genetics and the study of evolution" - and with the geneticist Theodosius Dobzhansky that "nothing in biology makes sense except in the light of evolution."[10]

Glenn Branch is Deputy Director of the National Center for Science Education.

 

ENDNOTES

1. Statement on evolution and creationism. Genetics Society of America, 2013. <http://genetics-gsa.org/policy/pp_evolution.shtml>.

2. Scott, E. C. 2009. Evolution vs. creationism: an introduction, 2nd ed. University of California Press. Berkeley.

3. Branch, G., Scott, E. C., Rosenau, J. 2010. Dispatches from the evolution wars: shifting tactics and expanding battlefields. Annual Review of Genomics and Human Genetics 11:317¬-338.

4. Graur, D., Zheng, Y., Price, N., Azevedo, R. B. R, Zufall, R. A., Elhaik, E. 2013. On the immortality of television sets: "function" in the human genome according to the evolution-free gospel of ENCODE. Genome Biology and Evolution doi: 10.1093/gbe/evt028.

5. Statement of consideration relating to 704 KAR 3:303 Kentucky Core Academic Standards. Kentucky Department of Education, 2013. <http://portal.ksba.org/public/Meeting/Attachments/DisplayAttachment.aspx?AttachmentID=178938>. Quotation from p. 113.

6. Lamb, M. J., Jablonka, E. 2005. Evolution in four dimensions: genetic, epigenetic, behavioral, and symbolic variation in the history of life. MIT Press. Cambridge, MA. Müller, G. B., Newman, S. A., editors. 2003. Origination of organismal form: beyond the gene in developmental and evolutionary biology. MIT Press. Cambridge, MA. Pigliucci, M., Müller, G. B., editors. 2010. Evolution: the extended synthesis. MIT Press. Cambridge, MA.

7. Pigliucci, M., Müller, G. B. Elements of an extended evolutionary synthesis. In: Pigliucci, M., Müller, G. B., editors. 2010. Evolution: the extended synthesis. MIT Press. Cambridge, MA. pp. 3-17. Quotation from p. 17.

8. Rosen, C. 2004. Preaching eugenics: religious leaders and the American eugenics movement. Oxford University Press. New York. Numbers, R. L. 1992. The creationists: the evolution of scientific creationism. Knopf. New York. See especially pp. 222-223. Tinkle, W. J. 1967. Heredity: a study in science and the Bible. St. Thomas Press. Houston.

9. Wallace, A. R. 1909. [Letter to Archdall Reid.] In: Marchant, J. 1916. Alfred Russel Wallace: letters and reminiscences. Harper & Brothers. New York. p. 340.

10. Charlesworth, B., Charlesworth D. 2009. Darwin and genetics. Genetics 183:757-766. Quotation from p. 764. Dobzhansky, T. 1973. Nothing in biology makes sense except in the light of evolution. The American Biology Teacher 35(3):125-129.


 
 
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