Darwin’s Gift to Science and Religion by Francisco J. Ayala 248 pages, bibliographic notes, paperback, $24.95 Joseph Henry Press, 2007, ISBN 978-0-30910-231-5
W. Malcolm Byrnes on This year, 2009, marks the one hundred The book contains ten chapters, as well as Darwin’s Gift to Science and Religion fiftieth anniversary of the publication of a notes section and an index. Chapter 1, the by Francisco J. Ayala Charles Darwin’s book The Origin of Spe- introduction, gives an overview of the book. cies. It is also the bicentennial of Darwin’s Chapter 2, “Intelligent Design: The Original birth. In early March of this year, a confer- Version,” presents William Paley’s original Brendan Sweetman on ence titled “Biological Evolution: Facts and argument, contained in his book Natural Body-Self Dualism in Contemporary Ethics and Politics Theories,” co-organized by the Pontifical Theology, for the existence of God based on by Patrick Lee and Robert P. George Gregorian University, the University of the design of organisms and the structures Notre Dame (Indiana), and the Vatican’s within them. Ayala presents Paley’s famous Pontifical Council for Culture and funded analogy of the watch and the watchmaker: Stephen Napier on in part by the John Templeton Foundation, a person traveling along a woodland path, Rethinking Informed Consent in Bioethics was held in Rome. Its purpose was to probe upon finding a watch lying on the ground, the relationship between faith and science as would come to the reasonable conclusion by Neil C. Manson and Onora O’Neill it relates to evolution. One of the speakers that the watch could not have arisen by at the conference was Francisco J. Ayala, a chance but instead must have been designed. professor of biology and philosophy at the J. Brian Benestad on Likewise, when one encounters the orga- University of California, Irvine. Ayala is a nized complexity of living organisms, Paley Human Dignity and Bioethics: prominent American evolutionary biologist argues, one will reasonably conclude that it Essays Commissioned by the President’s Council on Bioethics and the author of Darwin’s Gift. is the handiwork of God. The message that Ayala delivered at the A similar argument is used today by propo- Rome conference, and the main thesis of nents of what is known as intelligent design Jason T. Eberle on his book, is this: a belief in evolution does (ID). Consider, for instance, biochemist Artificial Nutrition and Hydration: not conflict with Christianity. Rather, Ayala Michael Behe’s argument for the existence The New Catholic Debate argues, Darwin’s theory of natural selection of an intelligent designer based on what he edited by Christopher Tollefsen has “gifted” religion by providing a solution perceives to be the irreducible complexity of to the age-old problem of how evil can ex- biological structures and systems such as the ist in a universe that was created by a God vertebrate eye, the bacterial flagellum, and who is both beneficent and omnipotent. In the immune system. According to this argu- other words, according to Ayala, Darwinian ment, since each of the individual parts of the evolution solves the “theodicity” problem. structure or system (e.g., the vertebrate eye) Moreover, as every biologist knows, Darwin’s depends intricately on the presence of the theory is a gift to science as well because it others within the whole, then all of the parts explains the unity of life, which has arisen on must have arisen together, as one integrated earth in all of its diversity from a common an- unit, not piecemeal. cestor through the process of natural selection Ayala marvels at Paley’s extensive knowl- acting on heritable variation within popula- edge of biology, but believes that Paley’s (and tions over eons of time. Much of the book is others’) argument for design falters when it concerned with unpacking this thesis. encounters the “imperfections, defects, pain,
The National Catholic Bioethics Quarterly Winter 2009 and cruelty of organisms” (21). He asks how It is gratifying to see Ayala accurately the existence of such “deficiencies” in nature portray Darwin as believing that evolution is could be consistent with an omnipotent and not necessarily progressive, especially given omniscient designer. “Paley cannot have it the temptation of some theologians to read both ways,” he writes (22). He cannot both “progress” into biological evolution, arguing believe in an all-knowing and all-powerful that it provides evidence that the universe God and also believe that nature, with all its is headed toward future fulfillment in God. imperfections, was designed by the same (This may be true, but does evolution provide God. Later in the book, in chapter 8, Ayala evidence for it?) Finally, it was the notion returns to this discussion. He gives examples that evolution is progressive, expressed in of the apparent cruelty of nature—predators the belief that races will improve through that eat their prey alive, females of certain selective breeding, which contributed to species of insects that eat their mates—and social Darwinism and eugenics. It is good writes, “The God of love and mercy could to recognize that these social phenomena not have planned all this” (159). are not extensions of Darwin’s original idea. In chapter 3 (“Darwin’s Revolution: Design They are misrepresentations of it. Without Designer”), Ayala describes Dar- In chapter 4, “Natural Selection,” Ayala win’s theory of natural selection, explaining further explains how natural selection works. that “Darwin’s greatest accomplishment Here, he hews close to the neo-Darwinian was to show that the complex organization paradigm of evolution, or what is known as and functionality of living beings can be the modern synthesis. It was the synthesis explained as a result of a natural process— of Gregor Mendel’s discoveries of the seg- natural selection—without any need to regation and independent assortment of resort to a Creator or other external agent” heritable traits with the discovery of genes on (42). In other words, Darwin provided a chromosomes as the units of inheritance that natural explanation for the design seen within provided a much-needed mechanism for the organisms. Ayala emphasizes that Darwin generation of heritable variation, something did not use the term “evolution,” but instead that Darwin’s original theory lacked. In this used such phrases as “common descent with chapter, Ayala describes the ins and outs of modification.” The term he did use, and the evolution by natural selection according the concept he did claim—enthusiastically—was neo-Darwinian paradigm, but he also brings natural selection. in other, newer, explanations for generating Ayala also compares and contrasts Dar- novelty. He mentions the Baldwin effect in win’s theory of natural selection with the which adaptive responses to the environ- apparently similar ideas of Alfred Russel ment can become genetically fixed, and the Wallace, who was Darwin’s contemporary. concept of “reaction norms” in which the He states that while Wallace thought that environment can call forth one of a range evolution was progressive, Darwin did not of phenotypes from a single genotype. He necessarily think it was. On the contrary, discusses adaptive radiation, describing Ayala writes, “Darwin . . . did not accept how the variable distribution of organisms that evolution would necessarily represent throughout the earth reveals evolution’s progress or advancement, nor did he believe “opportunism.” He presents the unique that evolution would always result in mor- flora and fauna of the Hawaiian Islands as phological change over time.” This is a very an example of this. He makes the subtle but penetrating observation by Ayala, one that important point that natural selection itself is seems to place him in the company of the not a random process: “The traits that organ- late Stephen Jay Gould (whom Ayala does isms acquire in their evolutionary histories not cite despite the similarity of some of his are not fortuitous, but rather determined by ideas to Gould’s, e.g., the idea that science their functional utility to the organisms” and religion represent nonoverlapping realms (77). He stresses that although the generation of knowledge). of traits on which natural selection works is
Book Reviews random, natural selection, which sifts and In the next two chapters, titled “Follies and sorts those traits, is not. Fatal Flaws” (chapter 8) and “Beyond Biol- Chapter 5, “Arguing for Evolution,” ogy” (chapter 9), Ayala takes on the propo- cites the evidence for evolution from sev- nents of ID. First, he counters the notion that eral sources, including the fossil record and evolution is “only” a theory. ID proponents embryology. Ayala cites “embryonic rudi- often say this in order to convince school ments,” such as the tail of four-week-old hu- boards that ID should be taught alongside man embryos, as proof that intelligent design evolution in the science classroom. But, Ayala cannot be true: “Why would some structure writes, “that evolution has occurred is, in be designed to form during early develop- ordinary language, a fact.” He disagrees with ment if it will disappear before birth?” (91). the assertion made by ID proponents that a In chapter 6, “Human Evolution,” Ayala failure of evolutionary theory to explain a nat- outlines what we know about human evolu- ural phenomenon means that the alternative tion, starting with the oldest hominids, which explanation provided by ID therefore must be lived six to seven million years ago, and correct. He calls this the “two-explanations moving to Australopithecus (three to four fallacy,” saying that ID must be able to stand million years ago), Homo erectus (1.8 million on its own, not gain its credibility from the years ago) and, finally, our species, modern failure of a rival explanation. The fact that humans, or Homo sapiens. He discusses it cannot—that there is no body of scientific Homo neanderthalensis, which appeared literature on which it is based—proves that in Europe around two hundred thousand it is not true science. This is essentially what years ago and disappeared less than thirty Judge John E. Jones said in 2005 in Kitzmiller thousand years ago. Once thought to be v. Dover Area School District: “ID is not sci- ancestral to modern humans, paleontologists ence and cannot be adjudged a valid, accepted now know that Neanderthals and modern scientific theory.” Further, he wrote that “the humans, who appeared in Africa around disclaimer [that the school district wanted to one hundred fifty thousand years ago, co- provide students in the classroom] . . . presents existed for tens of thousands of years. On the students with a religious alternative mas- topic of ethnicity and race, Ayala makes the querading as a scientific theory.” (171). Ayala interesting observation that the vast majority states that ID cannot be science because it (85 percent) of the genetic diversity present does not put forth any hypotheses of its own in the entire human population on earth is that can be tested empirically. also present within a single village. This is Emphasizing that science and religion are because the dispersal of humans around the separate but equally valid ways of finding globe from Africa is a relatively recent event truth, Ayala argues in chapter 9 that science in evolutionary terms, beginning only about does not deny the existence of religious one hundred thousand years ago. Moreover, values, meaning, or truth. He disagrees it turns out that the stereotypical traits that with some scientists and philosophers (e.g., explain the differences among the various Douglas Futuyma, Richard Dawkins, and “races” are based on very few genes. Thus, William Provine) who assert that to believe we humans are much more alike than we are in evolution is to believe that life is inherently different. What has uncovered this profound devoid of meaning and purpose. He writes fact is the analysis of genomes in an evolu- that “there is a monumental contradiction in tionary context. these assertions” because, while it is true that In chapter 7, “Molecular Biology,” Ayala science cannot prove that there is meaning explains how molecular phylogenetics, made and purpose in life, it is also equally true that possible by the sequencing of the genes science cannot deny such meaning and pur- and genomes of organisms, supports the pose (174). Citing Catholic biologist Kenneth conclusion that all life on earth arose from Miller and Catholic theologian John Haught, a common ancestor, that all life has a com- he notes that there are many who see no mon origin. essential conflict between Christianity and
The National Catholic Bioethics Quarterly Winter 2009 a belief in evolution. Such theistic evolution- very gradually through natural selection act- ists believe that God could create the world ing on genetic mutations generated randomly. through a mechanism in which creatures But others, notably biologists Lynn Margulis, adapt to environmental change over time, Scott Gilbert, and Stuart Newman, presented i.e., a world in which they evolve. other mechanisms (besides genetic mutation) If the first nine chapters of the book bring for how heritable variation can arise. Margulis up important but tried-and-true arguments discussed symbiogenesis, the generation of about science and religion, chapter 10, “Post- new life forms through the ancient symbiotic script for the Cognoscenti,” makes a uniquely association of ancestral organisms; Gilbert scholarly contribution to our understanding of talked about mechanisms for the generation Darwin’s thought process as a scientist. Ayala of anatomical diversity through changes in first states that there is a common misper- development (e.g., through heterochrony, ception that science is “inductive,” i.e., that due to changes in the timing or duration of science moves forward by gathering facts and the expression of developmental genes); and constructing general laws from those facts. Newman showed how “developmental pat- First proposed by Francis Bacon and John terning modules” present in ancient unicel- Stuart Mill, the “inductive canon” asserts that lular organisms could have acquired novel an inductive manner of proceeding allows functions simply by undergoing a change in scientists to reach conclusions objectively, scale and context that accompanied the rise without any preconceived notions of how of multicellularity around five hundred fifty things are. However, as Ayala argues, this million years ago. This, Newman argued, is not really how science proceeds. The way could have generated the animal body plans it really proceeds, he says, is that scientific and organ structures that exist today. The fact hypotheses—“creations of the mind”—are that these scientists were given a voice dem- proposed, and then these hypotheses are onstrates that the Vatican is truly interested rigorously subjected to “critical examination in knowing about the latest developments in and empirical testing” (188). Darwin, Ayala evolutionary biology as it contemplates issues argues, publicly claimed to proceed by the at the intersection of science and religion; it inductivist canon of Bacon and Mill but, in is not bound by a strict neo-Darwinian para- fact, he did science as any brilliant scientist digm of evolution, as are so many biologists, would: by letting his hypothesis (in this case, unfortunately. It is also noteworthy that of natural selection) guide his observations, the Vatican did not invite ID proponents to all the while testing it mercilessly. Ayala participate in the conference. The reason, ac- notes that it may have been Darwin’s public cording to Rev. Marc Leclerc, director of the reluctance to reveal the hypothesis (natural conference and a professor of philosophy of selection) behind his work that caused him to nature at the Pontifical Gregorian University, delay, for more than twenty years, the publi- was that ID was not appropriate because “it’s cation of The Origin of Species. It was only not a scientific perspective, nor a theological after Alfred Russel Wallace wrote Darwin a or philosophical one.”1 This certainly is a con- letter in which he revealed that he had discov- clusion with which Francisco Ayala, author of ered a similar explanation for evolution based Darwin’s Gift and speaker at the conference, on natural selection that Darwin was spurred would wholeheartedly agree. into action. In common scientific parlance, W. Malcolm Byrnes Darwin was afraid of being “scooped!” In conclusion, returning to the topic of the W. Malcolm Byrnes, Ph.D., is an associate pro- Rome conference mentioned at the beginning, fessor of biochemistry and molecular biology what was particularly encouraging about at Howard University College of Medicine in the conference was that it was very broad in Washington, D.C. considering possible mechanisms of evolu- 1 “Evolution at the Vatican,” Templeton Report, tionary change. Ayala presented the standard April 1, 2009, http://templeton.org/templeton_re- neo-Darwinian view that evolution proceeds port/20090401/.