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Word Gems exploring self-realization, sacred personhood, and full humanity
Dr. Stephen C. Meyer
return to "Evolution" main-page
from https://stephencmeyer.org/2001/05/16/the-meanings-of-evolution/
Principal Meanings of Evolution in Biology Textbooks6. “Blind watchmaker” thesis: the idea that all organisms have descended from common ancestors solely through an unguided, unintelligent, purposeless, material processes such as natural selection acting on random variations or mutations; that the mechanisms of natural selection, random variation and mutation, and perhaps other similarly naturalistic mechanisms, are completely sufficient to account for the appearance of design in living organisms. Evolution as the “Blind Watchmaker” Thesis. The “blind watchmaker” thesis, to appropriate Richard Dawkins’s clever term, stands for the Darwinian idea that all new living forms arose as the product of unguided, purposeless, material mechanisms, chiefly natural selection acting on random variation or mutation. Evolution in this sense implies that the Darwinian mechanism of natural selection acting on random variations (and other equally naturalistic processes) completely suffices to explain the origin of novel biological forms and the appearance of design in complex organisms. Although Darwinists and neo-Darwinists admit that living organisms appear designed for a purpose, they insist that such “design” is only apparent, not real, precisely because they also affirm the complete sufficiency of unintelligent natural mechanisms (that can mimic the activity of a designing intelligence) of morphogenesis. In Darwinism, the variation/selection mechanism functions as a kind of “designer substitute.” As Dawkins summarizes the blind watchmaker thesis: “Natural selection, the blind, unconscious, automatic process which Darwin discovered and which we now know is the explanation for the existence and apparently purposeful form of all life, has no purpose in mind. It has no mind and no mind’s eye.” In addition to the theory of universal common ancestry, classical “Darwinism” affirmed this sixth meaning of evolution. As Harvard evolutionary biologist Ernst Mayr has explained: “The real core of Darwinism, however, is the theory of natural selection. This theory is so important for the Darwinian because it permits the explanation of adaptation, the ‘design’ of the natural theologian, by natural means, instead of by divine intervention." Or as Mayr put it recently:
Further, not just classical Darwinism but contemporary neo-Darwinism has also affirmed this sixth meaning of evolution. Since the 1940s, the blind watchmaker thesis has been supported by the neo-Darwinian synthesis — which combined Mendelian genetics with Darwin’s theory of descent with modification. Neo-Darwinists proposed various types of random mutations as the creative engines giving natural selection the raw genetic material upon which to work. Many biologists before the 1940s had questioned the adequacy of Darwin’s mechanism precisely because they worried that natural selection did not have an adequate source of variation upon which to operate. Neo-Darwinists argued that the phenomena of mutations solved that problem by providing natural selection an unlimited source of genetic change. Thus, they, like the classical Darwinists before them, again affirmed the complete sufficiency of the (now) neo-Darwinian mechanism as an explanation for new living forms on Earth (and the appearance of design that they manifest). As George Gaylord Simpson would assert in his classic 1967 book, The Meaning of Evolution: “Man is the result of a purposeless and natural process that did not have him in mind. He was not planned.” As a result of the neo-Darwinian synthesis, biologists again assumed that a completely natural mechanism — natural selection acting on random mutations — could produce not only limited morphological change (and thus, patterns of limited common descent — evolution #3) but also unlimited morphological change (and thus the pattern of universal common descent — evolution #5). Neo-Darwinists also assumed that the new mutation/selection mechanism could account entirely for the appearance of design in biological systems. This view is reflected in many high school biology texts. As Kenneth Miller and Joseph Levine long asserted it in their popular text, “evolution works without plan or purpose.” Or as Purvis, Orians, and Heller tell students, “the living world is constantly evolving without any goals . . . evolutionary change is not directed." Similarly, Douglas Futuyma, in his widely used college textbook, Evolutionary Biology, writes: “By coupling undirected, purposeless variation to the blind, uncaring process of natural selection, Darwin made theological or spiritual explanations of the life processes superfluous. Francisco J. Ayala, president of the American Association for the Advancement of Science (AAAS) and chair of the National Academy of Sciences (NAS) steering committee for its 1999 edition of Science and Creationism (see analysis below), likewise speaks of Darwinism as having “excluded God as the explanation accounting for the obvious design of organisms. The blind watchmaker thesis suggests that the neo-Darwinian mechanism (and other related ones) functions as a designer substitute; it plays the role of creator in the scientific account of biological origins. Thus, clearly, this sixth meaning of evolution does have larger metaphysical or worldview implications. Many philosophical naturalists or materialists find support for their worldview in neo-Darwinian theory for what seems to them good reasons. If neo-Darwinism is true, God’s creative activity (whether expressed discretely or gradually) would no longer be necessary to explain the origin of new living forms, since a strictly naturalistic mechanism would suffice. Thus, a strictly naturalistic worldview would seem to provide a simpler account of reality, or at least of biological reality, than a theistic one. Further, if neo-Darwinism is true, then the natural world does not display evidence of actual design, divine or otherwise—as most religious theists affirm. For both of these reasons, neither neo-Darwinism nor other materialistic origins theories taught in the public schools (such as the chemical evolutionary theory of the origin of the first life) are religiously or metaphysically neutral. All strictly materialistic origins theories, if true, have implications that would seem to make a materialistic worldview more plausible than a theistic one and would also contradict some deeply held religious beliefs. Despite the confidence that many biologists and biology texts display in affirming the blind watchmaker thesis — evolution in the sixth sense — many scientists, including many biologists, have increasingly questioned the adequacy of the neo-Darwinian mechanism.19 Recently, a number of scientists have come to question whether natural selection acting on random variation can create the complex organs, molecular machines, and novel body plans that appear during the history of life. Such so-called macroevolutionary changes in the history of life — for example, the relatively sudden appearance of most extant and extinct animal phyla during the Cambrian explosion 530 million years ago — seem especially difficult to explain via the neo-Darwinian mechanism. As Gilbert, Opitz, and Raff have assessed the situation: “The Modern Synthesis is a remarkable achievement. However, starting in the 1970’s, many biologists began questioning its adequacy in explaining evolution. Genetics might be adequate for explaining microevolution, but microevolutionary changes in gene frequency were not seen as able to turn a reptile into a mammal or to convert a fish into an amphibian. Microevolution looks at adaptations that concern only the survival of the fittest, not the arrival of the fittest. Since the 1970s, many scientists have looked for additional naturalistic (or so-called self-organizational) mechanisms to show how extensive morphological innovation could arise—without, as yet, achieving much consensus or obvious success. Some scientists have questioned the sufficiency of the mutation/selection mechanism without proposing any alternatives. Still other scientists, such as Michael Behe, have proposed an alternative nonnaturalistic explanation for the origin of major innovations in the history of life, namely, the theory of intelligent design. Design theorists in general question the adequacy of the neo-Darwinian mechanism and see evidence of real (that is, intelligent) design, not just apparent design, in biology. Of course, many defenders of the neo-Darwinian mechanism remain, especially in fields such as population genetics, zoology, comparative anatomy, and molecular biology. Nevertheless, given the diversity of opinion within the scientific community, scientific integrity would seem to require teaching students about the controversy that has emerged among scientists about the blind watchmaker thesis. Further, given the larger metaphysical or worldview implications of that thesis, religious neutrality would also seem to require (a) avoiding the issue of design or purpose altogether, in which case neither classical Darwinism nor neo-Darwinism could be taught (since both make explicit claims about the origin of the appearance of design), or (b) teaching the controversy about the origin of this central feature of biological systems... Evolution as an “Unsupervised” and “Impersonal” Process: The Blind Watchmaker Thesis and the National Association of Biology TeachersThe NABT statement equivocates in other, arguably more significant, ways. For example, in 1995 the NABT issued the following statement: “The diversity of life on earth is the outcome of evolution: an unsupervised, impersonal, unpredictable and natural process of temporal descent with genetic modification that is affected by natural selection, chance, historical contingencies and changing environments.”29 Two years later the NABT deleted the words “unsupervised” and “impersonal” after two distinguished scholars, Alvin Plantinga and Huston Smith, wrote the NABT about the inappropriateness of those words: “Science presumably doesn’t address such theological questions, and isn’t equipped to deal with them. How could an empirical inquiry possibly show that God was not guiding and directing evolution?”30 The NABT Board of Directors took up that matter on 8 October 1997, voting unanimously to retain the objectionable wording. Wayne Carley, speaking for the board, said they felt “rather strongly” about keeping the statement unaltered. “We believe it. Evolution is real,” he affirmed.31 Carley did not say which meaning of the term evolution “is real,” nor did he acknowledge that Plantinga and Huston accept evolution in most of the other senses of the word (#1–4 and/or #5) but were disputing the sixth blind watchmaker thesis as advanced by the NABT. On the last day of the 1997 annual NABT meeting, the board met again and voted to remove the two objectionable words, “unsupervised” and “impersonal,” while maintaining: “The deletion of those two words would not affect the statement’s accurate characterization of evolution, and affirmation of evolution’s importance in science education.”32 Here again, implicit definitions shift from phrase to phrase. Many scientists, and indeed Plantinga and Huston, would accept “evolution’s importance to science” yet would not accept that scientific evidence has established that an “unsupervised” and “impersonal” (the two deleted words) mechanism is sufficient to explain the origin of every living system on Earth. But the NABT statement treats these two separate propositions as equivalent. If the NABT story ended here, some might think that statements affirming evolution in the sixth sense are on their way out. But most prominent evolutionary biologists do not see the blind watchmaker thesis (as defined above) as an optional ideological add-on to neo-Darwinian evolutionary theory. Rather, they see it as a central part of the propositional content of neo-Darwinian theory, as indeed Darwin himself did. Thus, the NABT leadership did not really repudiate its commitment to evolution in the sixth sense. They were merely responding to what Eugenie Scott perceptively called “a communication problem” (a public relations crisis).33 The NABT’s public relations campaign was soon challenged from the state of Tennessee. Massimo Pigliucci, assistant professor of ecology and evolution at the University of Tennessee, Knoxville, drafted “Defining Evolution: An Open Letter.” His letter was posted on the Darwin Day website as part of a moderated discussion that included contributions from Berkeley law professor (now emeritus) Phillip Johnson and Eugenie Scott of the National Center for Science Education (NCSE). Pigliucci enlisted the signatures of an impressive array of scientists, including Harvard’s Richard Lewontin, to support his rebuff of the NABT for their watering down of “evolution.” The letter urges the NABT to reconsider its change to the classroom definition of evolution in the name of “scientific and educational principles.” It argues that the NABT’s two-word alteration to the definition of evolution “betrays” the “core” of “high ideals” such as “rationalism and open inquiry.” What is this alleged core? The letter states:
The letter affirms that “all we know so far about the evolutionary process tells us that there is no supervision except for the action of natural selection.” Natural selection, for most evolutionary biologists, is the primary expression of the “blind watchmaker.” Without foresight it molds existing biological structures into new ones. Leading sociologist of science Steve Fuller, in a web-posted e-mail, “Why I Won’t Sign the Open Letter,” of 10 February 1998, wrote: “I found the Open Letter from the besieged biology teachers embarrassing. I’m sure there are some nasty things going on in Knoxville, but a petition of the sort circulating here is not the way to handle matters.” Fuller explained his embarrassment in these words: “To describe evolution as ‘impersonal’ and ‘unsupervised’ is indeed ideological, especially when the people behind this petition themselves claim that evolution can neither prove nor disprove the existence of God. It’s agnosticism upfront but atheism through the backdoor.”35 Fuller’s comment identifies the underlying reason for the public relations problem facing the science education establishment. On the one hand, for both public relations and constitutional reasons, public school science teachers and relevant professional societies must maintain ideological and religious neutrality. On the other hand, they are charged to teach a scientific theory that most prominent evolutionary biologists themselves understand to have decidedly metaphysical (indeed, antitheistic) implications. Caught on the horns of this dilemma, what is a principled science teacher to do? Well, why not acknowledge the dilemma and teach the scientific and philosophical controversies that arise from the origins issue? On the one hand, teachers should explain that what we are calling “mere evolution” (evolution #1–4) is “one of the strongest and most useful scientific theories we have,” to use NAS language. Mere evolution encompasses a vast number of specific cosmological, geological, and biological theories that “incorporate a large body of scientific facts, laws, tested hypotheses, and logical inferences.” On the other hand, teachers should help students understand that a significant minority of scientists dissent on evidential grounds from the theory of universal common descent (evolution #5), and an even greater group dissents from the blind watchmaker hypothesis (evolution #6). The equivocal use of the term evolution conceals this dissent and prevents open classroom discussion of legitimate scientific controversy and its associated evidential grounds. Further, science teachers need not ignore the larger philosophical or worldview issues that arise from discussing, for example, the blind watchmaker thesis. The threat of ideological indoctrination does not come from allowing students to ponder the philosophical questions raised by the origins issue. Instead, it comes from force-feeding students a single perspective. The best way to prevent indoctrination is to teach about the scientific controversies that surround the ideologically charged senses of the term evolution. But this can be accomplished only if teachers first define the “E” word precisely, distinguish its many distinct meanings (both uncontroversial and controversial), and allow dissenting scientific opinion about the latter meanings to have a voice in the classroom. Given the interest that such an approach would surely generate among students, one might wonder why informed biology teachers would do anything else.
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