Darwin's Dangerous IdeaDramatizations of Darwin's life, interspersed with commentaries by philosopher Daniel Dennett, biologist Stephen Jay Gould, and historian James Moore. Darwin's theory that all living things evolved from a common ancestor in one "great tree of life." Drug resistance in HIV. Biologist Kenneth Miller on the vertebrate eye and the role of God. Similarities between humans and apes. A. The Voyage of the BeagleCharles Darwin originally tried to follow a family tradition of studying medicine, but he found it not to his liking and switched to divinity school instead. Darwin possessed an abiding interest in nature, however, and in 1831 he took a position as ship's naturalist on board H.M.S. Beagle, which the British navy was sending to chart the waters off South America. Darwin also served as a traveling companion for the ship's captain, Robert FitzRoy. In the PBS series, the curtain rises on a dramatization of Charles Darwin and Captain Robert FitzRoy purchasing a mammal fossil from some herdsmen in South America in 1833. As Darwin and FitzRoy complete the purchase, an exchange between them sets the stage for the entire series:
This dramatization distorts the historical facts. Although FitzRoy was raised in a very religious household, while voyaging on the Beagle his views were much closer to Darwin's than this fictitious exchange implies--both because FitzRoy was not so literalistic, and because Darwin was not so skeptical. It was only several years later that FitzRoy took to defending a literal interpretation of Genesis against Darwin's views. By reading FitzRoy's later views back into this period, the Evolution project starts right off by promoting a stereotype that will re-appear throughout the series: Rational scientists accept the evidence in order to understand the reality of the natural world, but they are opposed by irrational fundamentalists who reject the evidence in order to preserve a literal interpretation of the Bible. The truth is that Darwin's theory was opposed in the nineteenth century by many eminent scientists. While most scientists became persuaded that some kind of evolution occurred, many of them disputed Darwin's claim that it was driven by an unguided process of natural selection acting on random variations. Instead, leading scientists advocated a type of guided evolution that flatly contradicted Darwin's core thesis. Because of such scientific criticism, according to historian Peter Bowler, Darwin's theory of evolution by natural selection "had slipped in popularity to such an extent that by 1900 its opponents were convinced it would never recover." In addition to being opposed by scientists, Darwin's theory was opposed by a broad spectrum of religious believers. But the makers of Evolution simply ignore this rich and fascinating history. In the next scene, Darwin rolls his eyes skeptically in his cabin as FitzRoy reads from the Book of Genesis on the deck above. In actuality, however, Darwin regularly attended the shipboard worship services conducted by FitzRoy. Like the preceding fictionalized scene, this one distorts the historical facts in order to promote the scientist-vs.-fundamentalist stereotype. And both scenes put the lie to Evolution's claim to be only about science, not religion.See . According to historian Janet Browne, FitzRoy at the time of the Beagle voyage was "much inclined to believe [Geologist Charles] Lyell's revisionist anticlerical arguments" against the historicity of Noah's Flood: B. Darwin's Dangerous IdeaFrom the Beagle in the 1830s the scene shifts to the present, for an interview with Tufts University philosopher Daniel C. Dennett: "If I were to give a prize for the single best idea anybody ever had, I'd give it to Darwin for the idea of natural selection--ahead of Newton, ahead of Einstein. Because his idea unites the two most disparate features of our universe: The world of purposeless, meaningless matter-in-motion, on the one side, and the world of meaning, and purpose, and design on the other. He understood that what he was proposing was a truly revolutionary idea." This entire two-hour episode is named after Dennett's 1995 book, Darwin's Dangerous Idea, which compares Darwin's theory to a "universal acid" that "eats through just about every traditional concept"--including the concept of God. Dennett's book also calls anyone who rejects Darwin's theory "inexcusably ignorant."See . Daniel Dennett believes that Darwinian evolution is not only unquestionably true, but also bears "an unmistakable likeness to universal acid--it eats through just about every traditional concept." (Darwin's Dangerous Idea: Evolution and the Meanings of Life [New York: Simon & Schuster, 1995], 63) In other words, Dennett sees a conflict between Darwin's theory and all traditional forms of religion--not just biblical fundamentalism. The interview with Dennett is followed by one with Harvard University evolutionary biologist Stephen Jay Gould, who says: "The Darwinian revolution is about who we are--it's what we're made of, it's what our life means insofar as science can answer that question. So it, in many ways, was the singularly deepest and most discombobulating of all discoveries that science has ever made." Following Gould, Open University historian James R. Moore adds: "In Darwin's day the idea of evolution was regarded as highly unorthodox, because it went against all of natural history in Great Britain. It jeopardized the standing of science, it did jeopardize the standing of a stable society, the Bible, and the Church as well." We will meet all three of these men several more times in this episode. Evolution's producers claim that they "examine empirically-testable explanations for `what happened,' but don't speak to the ultimate cause of `who done it'--the religious realm." But Dennett and Gould address issues of meaning and purpose that are normally considered to be in the province of religion, and Moore describes the challenge Darwin posed to society and religion. It seems that Evolution has things to say about the religious realm after all. C. The Legend of "Darwin's Finches"The interviews with Dennett, Gould and Moore are followed by some more imaginary scenes with Charles Darwin, his brother Erasmus, Captain FitzRoy and others--many serving to reinforce the scientist-vs.-fundamentalist stereotype. At one point Charles Darwin meets with ornithologist John Gould, who informs him that some birds Darwin had collected on the Galápagos Islands (600 miles west of Ecuador) were finches. Darwin later suggests to FitzRoy that some finches had been blown to the islands from the South American mainland and then diverged into the separate species now present. In a subsequent scene, John Gould tells Darwin that the Galápagos finches he collected differ mainly in the size and shape of their beaks. Darwin cradles one bird in his hand and remarks: "And they're all descended from this one--the common ground finch!" Darwin's eyes light up and he rushes out of the room to tell his brother that he has finally put the pieces together. "Perhaps everything is part of one ancestral chain," Darwin concludes, and the finches are simply one branch on the great "tree of life." The scene then shifts to a rainforest in present-day Ecuador, where Boston University biologist Chris Schneider tells us: "One of the most important ideas that Darwin had was that all living things on Earth were related. How can you realize that you are part of this single tree of life and not be fundamentally moved by that? It's something that stirs the soul." Schneider and his colleagues are studying various animals, the narrator tells us, to "understand how changing environments might trigger the evolution of new species." One of Schneider's colleagues studies differences in birds' beaks, and the narrator explains: "Even subtle differences may offer clues as to how and why new species arise--just as it was the beaks of finches from the nearby Galápagos Islands that spurred Darwin's thinking in the 1830s. Darwin saw that the finches he brought back had uniquely shaped beaks adapted to the different foods on the islands. He envisioned that these different species of finch had all descended with modifications from a common ancestral population that had flown over from the mainland. Darwin's bold insight was to apply this vision to all of life." This story of "Darwin's finches" is re-told in many biology textbooks, but it is largely fictional. In fact, the Galápagos finches had almost nothing to do with the process by which Darwin arrived at his theory. Much of his information about the birds was erroneous, and since he never visited South America north of Peru he was unaware of differences between the Galápagos birds and those on the mainland. Darwin did not even mention the finches in The Origin of Species. It wasn't until a century after his voyage on the Beagle that variations in the birds' beaks were correlated with different food sources, and only then were they named "Darwin's finches" in his honor. Although other Galápagos animals impressed Darwin, the finches did not, and the account presented in this episode is more legendary than historical. This may seem like a minor point, but it is symptomatic of a tendency among Darwin's admirers to give the man credit for things he never did.See . According to historian of science Frank Sulloway, Darwin "possessed only a limited and largely erroneous conception of both the feeding habits and the geographical distribution of these birds." And as for the claim that the Galápagos finches impressed Darwin as evidence of evolution, Sulloway wrote, "nothing could be further from the truth." (Journal of the History of Biology 15 [1982], 1-53; Biological Journal of the Linnean Society 21 [1984], 29-59.) D. Darwin's Tree of LifeAccording to the narrator, Darwin's "bold insight" is "now the bedrock of biology. All forms of life on Earth have evolved from a single branching tree of life." Darwin saw "that the great variety of life on Earth--leopards and lichens, minnows and whales, flowering plants and flatworms, apes and human beings--all descended from one root, one common ancestor." Enter Stephen Jay Gould again: "It was, indeed, another one of his radical proposals not only to say that evolution happened, but that there was a root, a common ancestry, to everything that lived on this planet--including us. You could construe it in another way, that is (I like to say) more user-friendly: You could have thought, well, God had several independent lineages and they were all moving in certain pre-ordained directions which pleased His sense of how a uniform and harmonious world ought to be put together--and Darwin says, No, it's just history all coming [through] descent with modification from a single common ancestry." James Moore makes another appearance, declaring: "The key to Darwin's thought in every realm is that given enough time, and innumerable small events, anything can take place by the laws of nature." This includes the raising of mountains and the evolution of new species. These statements seem strangely out of place here. Why does a program that ostensibly wants to avoid "the religious realm" have Stephen Jay Gould tell us--by his tone, if not in words--that Darwin's theory is preferable to divinely guided separate lineages? And why does a program that has "enlisted the top minds in all of the sciences" rely on a historian to assure us that anything can take place by the laws of nature, given enough time? The scene now switches back to South America again, where biologists are finding camouflaged insects and measuring the beaks of hummingbirds. The narrator tells us that these birds all evolved from a common ancestor, and that scientists now compare their DNA to determine how long ago they diverged from that ancestor. But in these DNA comparisons common ancestry is simply assumed; where is the evidence for it? And even though the common ancestry of hummingbirds seems plausible, how do we know that "leopards and lichens, minnows and whales, flowering plants and flatworms, apes and human beings" also share a common ancestor? The only actual evidence mentioned in this episode is the supposed universality of the genetic code. According to the narrator: "The fact that the blueprints for all living things are in the same language--the genetic code of DNA--is powerful evidence that they all evolved on a single tree of life." So the genetic code is supposed to be hard evidence for Darwin's theory that all living things share a common ancestor. Let's take a closer look at it. DNA is like a string of words that tells a cell how to make the proteins it needs. DNA words, however, are different from the words we use. In English, we use an alphabet of 26 letters, from which we make thousands of words of varying length. DNA, on the other hand, uses an alphabet with only four letters, and it makes only three-letter words--a total of 64 of them. Some of these three-letter words tell the cell to start or stop making a protein, while the others stand for 20 kinds of subunits that the cell uses to assemble it. DNA words--corresponding to a start or stop signal, or to one of the 20 protein subunits--make up "the genetic code." In the early 1970s, evolutionary biologists thought that a given DNA word specified the same protein subunit in every living thing, and that the genetic code was thus universal. This was unlikely to have happened by chance, so it was interpreted as evidence that every organism had inherited its genetic code from a single common ancestor. In 1979, however, exceptions to the code were found in mitochondria, the tiny energy factories inside cells. Biologists subsequently found exceptions in bacteria and in the nuclei of algae and single-celled animals. It is now clear that the genetic code is not the same in all living things, and that it does not provide "powerful evidence" that all living things "evolved on a single tree of life."See . The universality of the genetic code was suggested by Francis Crick in "The Origin of the Genetic Code," Journal of Molecular Biology 38 (1968), 367-379. Exceptions to the code are reviewed in Syozo Osawa, Evolution of the Genetic Code (Oxford: Oxford University Press, 1995), and in Robin D. Knight, Stephen J. Freeland and Laura F. Landweber, "Rewiring the Keyboard: Evolvability of the Genetic Code," Nature Reviews: Genetics 2 (2001), 49-58. For a current list of exceptions to the genetic code, go to: So the first hard evidence that we are given for Darwin's tree of life turns out to be false. The scene in the South American rainforest concludes with Chris Schneider climbing a tower that reaches high into the trees. Schneider asks: "How is it that organisms that are so different can be related--that we are related to a flatworm, or a bacteria? Darwin emphasized that small changes would accrue every generation, and these changes could build up to amount to enormous changes. It's not really hard to understand how major transitions could come about, given that life has been around for three and a half billion years." Schneider concludes by assuring us that "Darwin really had it right." In science, however, assurances are not enough; we must also have evidence. So far, we have been told that the universality of the genetic code is "powerful evidence" for the relatedness of all living things. But that "evidence" turns out to be false. How about Schneider's assurance that an accumulation of slight differences through natural selection can produce the enormous differences among living things? Where is the evidence for that? We haven't seen any so far, but let's be patient. Maybe some is on the way. E. Natural Selection in HIVThe episode moves on to some more dramatizations involving Darwin and his family, and some return appearances by James Moore and Stephen Jay Gould (who outline Darwin's theory of natural selection). We are then treated to some beautiful wildlife photography of animals engaged in the struggle for survival. Despite its faults, the Evolution series periodically delights us with colorful and captivating footage of the amazing creatures that inhabit our planet. (The colorful footage, however, is not evidence for evolution.) The narrator continues: "Darwin couldn't actually see natural selection acting in real time. But today scientists can, by observing the evolution of HIV, the virus that causes AIDS." The scene shifts to an AIDS patient who, we are told, "takes a host of medications, but to little avail. The virus keeps adapting, evolving into new strains that evade the drugs." The scene switches to another AIDS patient, who is also "locked in a daily struggle against the rapidly evolving virus." According to the narrator, the physician treating the second patient "has seen HIV evolve into new varieties over the last dozen years. The virus is constantly changing, subject to the forces of natural selection, in the environment of the patient's body." This occurs because a drug kills some viruses, but others acquire chance immunity to it and survive. The survivors then resist further treatments by that particular drug. The attending physician describes this process of evolution: "In the case of HIV, we're talking about minutes to hours to move from one species to another. It's mind-boggling." It's also untrue. The acquisition of drug resistance by HIV is a far cry from moving "from one species to another." The HIV at the end of the treatment is the same species (actually, it's called a "quasispecies") as the HIV at the beginning of the treatment. This is clear from the fact that the virus reverts to its previous condition when treatment is stopped. (Furthermore, HIV reproduces about every 24 hours, so whatever changes are occurring would take days instead of "minutes to hours.")See . Swarms of HIV variants--which may include drug-resistant strains--are called "quasispecies." See Esteban Domingo et al., "Basic concepts in RNA virus evolution," FASEB Journal 10 (1996), 859-864; and Michael H. Malim and Michael Emerman, "HIV-1 Sequence Variation: Drift, Shift, and Attenuation," Cell 104 (2001), 469-471. But changes within a species--such as we observe in the case of HIV--are nothing new. For centuries, farmers have been producing dramatic changes in crops and livestock by artificially selecting certain specimens for breeding. In fact, Darwin and his contemporaries took the success of domestic breeding for granted. But well-bred cows are still cows, and well-bred corn is still corn. The revolutionary claim in Darwin's theory was that the natural counterpart of artificial selection can create not only new species, but also new forms of organisms. The enormous differences we now see between "leopards and lichens, minnows and whales, flowering plants and flatworms, apes and human beings" go far beyond the small differences we observe in domestic breeding. But artificial selection does not produce new species, much less new forms of organisms, and this has been a major stumbling block to evolutionary theory since the time of Darwin. The HIV story does nothing to overcome this stumbling block. It does not show the origin of a new species; it shows only the sorts of minor changes within species that people have been observing for centuries. So it provides no support for Darwin's theory that natural selection can produce new species and higher level forms. Enter Stephen Jay Gould and Daniel Dennett again. According to Gould: "All that happens in evolution, at least under Darwinian natural selection, is that organisms are struggling, in some metaphorical and unconscious sense, for reproductive success, however it happens." Dennett adds: "The process of natural selection feeds on randomness, it feeds on accident and contingency, and it gradually improves the fit between whatever organisms there are and the environment in which they're being selected. But there's no predictability about what particular accidents are going to be exploited in this process." So instead of presenting us with evidence, this episode merely offers us more assurances that natural selection can, indeed, do what Darwin said it could do--and that it's random. The focus shifts back to treating AIDS patients, and how evolutionary thinking allegedly helps them. But the question with which we started was: What is the evidence that natural selection can produce "leopards and lichens, minnows and whales, flowering plants and flatworms, apes and human beings" from one common ancestor? And our question remains unanswered. F. The Evolution of the EyeMore dramatizations follow, culminating in an important conversation between Darwin and his wife, Emma:
James Moore returns and says Emma "saw that her husband's speculations about the origins of species and of humanity would jeopardize the Christian plan of salvation. God was being made remote in her husband's universe. Now if nature, by itself, unaided by God, could make an eye, then what else couldn't nature do? Nature could do anything! It could make everything!" Brown University biologist Kenneth R. Miller elaborates: "In Darwin's day, the very existence of an organ of extreme perfection like the eye was taken by many as proof of God, as proof of a Designer. How else could all the intricate organs and substructures of the eye have come together in just the right way to make vision so possible, and so perfect? But it turns out the eye isn't exactly perfect after all. In fact, the eye contains profound optical imperfections. And those imperfections are proof, in a sense, of the evolutionary ancestry of the eye." After calling the multi-layered structure of the eye an evolutionary defect (because it can lead to retinal tears as people grow older), the narrator tells us that another defect "occurs because nerve cells and blood vessels evolved to lie in front of the retina, where they interfere with its ability to form sharp images. It's like trying to take a picture through a foggy piece of glass. Now the optic nerve itself evolved to connect to the brain through a hole in the retina. So the eyes of all vertebrates have a small blind spot, right near the middle of the visual field." Miller attributes this to natural selection: "Evolution starts with what's already there, tinkers with it, and modifies it, but can never do a grand re-design. So even the eye, with all of its optical perfection, has clues to the fact that its origin is of the blind process of natural selection." But does imperfection count as evidence against design? Many cars are noticeably imperfect, though they are all designed. Every time a manufacturer recalls a faulty product we are confronted with an example of imperfect design. Miller is actually relying here on an unstated theological argument (as Darwin often did in The Origin of Species)--namely, that if God had made it, it would be perfect; but it's not perfect, so God didn't make it, and evolution must have. But why does an argument for evolution have to resort to theology? In any case, it turns out that the vertebrate eye is not as imperfect as Miller claims. The light-sensing cells in the eyes of higher vertebrates are extremely efficient at amplifying faint light. The efficient, hard-working tips of the light-sensing cells need lots of energy, and they also need to be constantly regenerated. The energy is provided by a dense bed of capillaries, and the regeneration is facilitated by a special layer of epithelial cells. If the tips of the light-sensing cells faced forward, as Miller thinks they should, incoming light would be blocked by the dense capillary bed and the epithelial layer. Such an eye would be much less efficient--and therefore less perfect--than the one we have now, because the capillaries and epithelial cells are now behind the retina instead of in front of it. It's true that the present arrangement causes the optic nerve to leave a blind spot as it passes through the retina; but vertebrates have two eyes, and the blind spots cancel out when both are used to focus on the same object. Despite Miller's claim, the vertebrate eye seems to be a masterpiece of engineering! Another problem with Miller's argument is its implication that the retina of vertebrate eyes is backwards because evolution was forced to tinker with something it already had. But animals regarded as evolutionarily more primitive than vertebrates all have retinas that face forward . There is no backwards retina in a primitive animal that could have served as an evolutionary precursor to the vertebrate eye. So where is Miller's "proof" of the evolutionary ancestry of the vertebrate eye? Stephen Jay Gould returns to explain that "what Darwin was able to do was to point out that you might think in logic that it's difficult to imagine a set of intermediary stages between the simplest little spot of nerve cells that can perceive light to a lens-forming eye that makes complex images, but in fact these intermediary forms do exist in nature." We are shown colorful pictures of eyes in various animals, but all of them are complex; none of them are "intermediary forms." The scene then shifts to Sweden, where Lund University zoologist Dan-Eric Nilsson has performed calculations and made a model to show how "we can go all the way gradually, in very small steps, from a simple pigment cup-eye--which has barely got the ability to determine the direction of a light source--all the way to a complete camera-type eye, the same type as we have ourselves." Nilsson's interesting presentation is periodically interrupted by more pictures of animals, this time showing presumably intermediary forms--including a flatworm with a simple cup eye, a chambered nautilus with a pin-hole camera eye, and some vertebrates. But no biologist believes that chambered nautiluses evolved into vertebrates, so it's not clear what relevance these forms have to the argument. Nevertheless, Nilsson concludes: "And that is really exactly the way eye evolution must proceed." Nilsson's hypothesis, however, requires a pre-existing layer of light-sensing cells, and these require the simultaneous presence of several extremely complex and specialized molecules. According to Darwin's theory, such a complex molecular apparatus must have formed as a result of innumerable small steps, but no one knows how this could have happened. The origin of the light-sensitive cells that Nilsson needs for his hypothesis remains a mystery. Furthermore, in order for evolution to work, variations must be heritable--that is, they must be passed on to subsequent generations. There is no known mechanism by which real organisms could generate the variations envisioned by Nilsson, much less pass them on to subsequent generations. So Nilsson's mechanism--plausible though it may seem--has no counterpart in living things.See . The idea that the vertebrate eye is imperfect, and therefore must be a product of Darwinian evolution, did not originate with Kenneth Miller. In his 1986 book, The Blind Watchmaker (New York: W. W. Norton), Richard Dawkins wrote: We are not told about these problems, however, and the narrator concludes: "He [Darwin] later wrote that eyes must have evolved by numerous gradations from an imperfect and simple eye to one perfect and complex, with each grade being useful to its possessor. Nature, unaided by a designer, could produce an organ of seemingly miraculous complexity." So we are assured that surely eyes must have evolved this way. But did they, really? G. More on Darwinism and ReligionMore dramatizations follow, including some poignant scenes about the death of Darwin's daughter, and the effect this tragedy had on his religious faith. Whatever one may think of Darwin's theory, there is no denying that he was an interesting man, and the dramatizations in this episode help to bring him alive for us. After James Moore and Stephen Jay Gould comment on Darwin's religious views, the scene shifts to a Roman Catholic Church, where Kenneth Miller sits listening to a children's choir sing "All Things Bright and Beautiful." The narrator explains: "Today scientists hold all conceivable views on religion--from atheism, to agnosticism, to a general spirituality. And many, like biologist Ken Miller, adhere to very traditional beliefs." "I'm an orthodox Catholic, and I'm an orthodox Darwinist," Miller says. "My idea of God is: Supreme being who acts in concert with the principles and the ideas that Darwin explained to us about the origin of species. My students often ask me, You say you believe in God--well what kind of God? Is it a fashionable New Age God, a pyramid-power kind of God? Do you think, like some scientists do, that God is the sum total of the laws of physics? And I shake those off and say that my religious belief is entirely conventional." The congregation recites the "Our Father" in the background as Miller continues: "It surprises students very often that anyone could say that, that kind of very traditional, conventional religious belief could be compatible with evolution, but it is. I find this absolutely wonderful consistency with what I understand about the universe from science and what I understand about the universe from faith." In the next scene, Miller is being interviewed on a radio program in Knoxville, Tennessee, about his recent book, Finding Darwin's God. "What room is there for God in present-day life?" Miller asks himself, then answers: "Well, I think if you ask people who are believers, How does God act?--they would say He acts in a variety of ways. He answers our prayers; He inspires us. No doubt there are events that take place that are part of what some people might call God's plan. And what I would suggest is--if you look back in Earth's history--if God is working today in concert with the laws of nature, with physical laws and so forth, He probably worked in concert with them in the past. In a sense, in a sense, He's the guy who made up the rules of the game, and He manages to act within those rules."See . Darwin's view, at least when he wrote The Origin of Species, seems to have been that God created the universe and the natural laws that govern it, but then turned it loose to run by itself. Unlike many others who hold this view, however, Darwin believed that the law of natural selection cannot produce any determinate outcome, so no specific result of evolution is fore-ordained. As Darwin wrote in a letter to Asa Gray in 1860, he was "inclined to look at everything as resulting from designed laws, with the details, whether good or bad, left to the working out of chance." (Francis Darwin, ed., The Life and Letters of Charles Darwin [New York: D. Appleton, 1887], II:105-106) See also Jonathan Wells, Charles Hodge's Critique of Darwinism: An Historical-Critical Analysis of Concepts Basic to the 19th-Century Debate (Lewiston, NY: Edwin Mellen Press, 1988). The narrator explains: "For Miller, and millions of followers of all major religions, notions of God and evolution are fully compatible. But not everyone agrees." Daniel Dennett comes on again and says: "When we replace the traditional idea of God the creator with the idea of the process of natural selection doing the creating, the creation is as wonderful as it ever was. All that great design work had to be done. It just wasn't done by an individual, it was done by this huge process, distributed over billions of years." A clergyman then reads to his congregation from the Bible: "God created man in His image, in the image of God He created him; male and female He created them." As the clergyman continues speaking in the background, Dennett remarks: "Whereas people used to think of meaning coming from on high and being ordained from the top down, now we have Darwin saying, No, all of this design can happen, all of this purpose can emerge from the bottom up, without any direction at all. And that's a very unsettling thought for many people." Some comments by James Moore are followed by more dramatizations featuring Darwin and his contemporaries. These include Darwin's receipt of Alfred Russel Wallace's manuscript outlining a theory very similar to his own (which prompted Darwin finally to publish his theory in The Origin of Species), and a re-enactment of the famous 1860 confrontation between Bishop Samuel Wilberforce and Darwin's defender, Thomas Henry Huxley. Though much of the history in these dramatizations is accurate, it downplays the scientific opposition to Darwin's theory and over-emphasizes the religious opposition. If we had any doubt before, it is now absolutely clear--despite what the producers claim--that the Evolution project has quite a lot to say about "the religious realm." After presenting us with a variety of conflicting religious viewpoints, it leaves us with the distinct impression that some of them are acceptable while others are not. How can we tell the difference between the good and the bad? By their attitudes toward Darwinian evolution. Religion that accepts Darwin's theory is good, while religion that doesn't is bad. So the PBS Evolution series is far from neutral on religious issues. It has a very specific agenda when it comes to "the religious realm." That agenda was subtly introduced in the very first scene; it becomes more explicit here; and--as we shall see in the last episode--it turns out to be one of the major take-home lessons of the series. H. Are Humans Just Animals?The concluding scenes of this episode tackle the question of whether there is more to human beings than their animal nature. Daniel Dennett addresses the question first: "For more than a century, people have often thought that the conclusion to draw from Darwin's vision is that Homo sapiens--our species--that we're just animals, too, we're just mammals, that there is nothing morally special about us. I, in myself, don't think this follows at all from Darwin's vision, but it is certainly the received view in many quarters." Watch closely now as the camera pans over a stack of books critical of Darwinism. The narrator says: "Ever since The Origin of Species was published, strict believers in biblical creation have attacked Darwin's vision. Their concerns aren't only about the science of evolution. At stake, many believe, is nothing less than the human soul." But two of the books in the stack are by critics of evolution who are not strict believers in biblical creation. Darwin On Trial is by Phillip E. Johnson, a Berkeley law professor who is a Christian but who accepts the geological evidence for an old Earth; and Darwinism: The Refutation of a Myth is by Søren Løvtrup, an evolutionary biologist. Yet Evolution misrepresents them as biblical literalists simply because they are critical of Darwin's theory. James Moore continues: "To suggest that animals and plants--and us!--came into being in a natural, law-like way, in the way the planets move, was to put in jeopardy the human soul. And the human soul is the crux of the matter, because if we are not different from animals--if we don't live forever, in heaven, or in hell--then why should we behave other than like animals in this life?" The scene shifts to chimpanzees. We are told that in Darwin's time there was not much evidence that chimps and humans are closely related, but the fossil record and DNA studies have since shown that they are. Similarity, especially in the DNA, supposedly shows that we come from a common ancestor. There are similarities in the way we learn, too. Ohio State University developmental psychologist Sally Boysen concludes from this that humans and chimps "have a great deal of commonality in--literally--the neurological structure that supports their ability to learn just like we do. Those things are absolutely comparable, and had to come from a common ancestor." Kenneth Miller returns to the screen to tell us that for all of the extraordinary similarities between us and the apes, "there are striking differences," which he attributes to natural selection. According to Miller, "Darwin's great idea is a grand and marvelous explanation that shows us that we are united with every other form of life on this planet. And I find that an exciting, and maybe even ennobling way, to look at things." So, are we just animals, built to behave like them--or are we morally special, with immortal souls? Dennett thinks the former doesn't follow from Darwin's theory; Miller, as an orthodox Darwinist and an orthodox Catholic, presumably agrees; and Moore acknowledges that this question is "the crux of the matter." Boysen thinks our similarities with chimps mean we had to come from a common ancestor, but she doesn't comment on the larger question, which remains unanswered.See . The two books in the pile that are not by "strict believers in biblical creation" are Darwin On Trial, by Phillip E. Johnson (Washington, DC: Regnery Publishing, 1991), and Darwinism: The Refutation of a Myth, by Søren Løvtrup (London: Croom Helm, 1987). Johnson, though a Christian, does not hold to a literal six-day creation or six-thousand year history. Løvtrup is an evolutionary biologist. As we saw above, however, in the scene with the stack of books, anyone critical of Darwinian evolution risks being stereotyped as a strict believer in biblical creation. The message seems to be that it's OK for people to believe whatever they want about God and the soul--as long as they don't criticize evolution. Once again, there's good religion and there's bad religion--and Darwinism enables us to distinguish between the two. The episode ends, appropriately, with Darwin's death. Moore concludes by telling us that Darwin was accorded great honor because "he had naturalized creation, and had delivered human nature, and human destiny," into the hands of those who were running the technological society of late nineteenth-century England. "Society would never be the same. Darwin's vision of nature was, I believe, fundamentally a religious vision." Notes
In particular, FitzRoy doubted the existence of a Noachian Flood--the traditional stumbling-block for Protestants since the seventeenth century. . . . He could not believe that the extensive gravel and clay deposits of Patagonia, hundreds of feet thick and apparently originating in calm water, had been laid down in forty days. Lyell's secular proposals seemed altogether more probable. He said as much to Darwin while they tramped the coastal plains puzzling over the sequence of deposition. To understand these deposits was important in relation to the fossil mammals and FitzRoy was as keen to unravel the conundrum as Darwin. (Janet Browne, Charles Darwin, Voyaging: Volume I of a Biography [New York: Knopf, 1995], 272-273) During the Beagle voyage, Darwin's religious views were largely indistinguishable from those of FitzRoy. (Such disagreements as they had concerned the topic of slavery [see Browne, 199] and social niceties.) Indeed, during the voyage, FitzRoy and Darwin composed a joint letter defending the work of English missionaries in Tahiti and New Zealand (Browne, 330). Furthermore, as Browne reports: [Darwin] went to church regularly throughout the voyage, attending the shipboard ceremonies conducted by FitzRoy and services on shore whenever possible. He and [naval lieutenant Robert] Hammond, spent some hours in Buenos Aires waiting to hear if they could receive communion from the English chaplain stationed there before going to Tierra Del Fuego. . . . The Beagle Darwin, though occasionally doubtful, was by no means a thorn in the side of the church. (326) According to Gertrude Himmelfarb: "Most biographers, carried away by the zeal of hindsight, tend to hasten the development of Darwin's religious views [i.e., away from orthodoxy], as they do his evolutionary views. . . . [But there is a] total lack of evidence on this score." Furthermore: Several times during the voyage he [i.e., Darwin] alluded to the vision of a quiet English parsonage glimpsed through a grove of tropical palms. To a college friend already installed in a country parish he wrote [in Nov. 1832]: "I hope my wanderings will not unfit me for a quiet life and that on some future day I may be fortunate enough to be qualified to become like you a country clergyman. And then we will work together at Natural History." And again the following year [May 23, 1833]: "I often conjecture what will become of me; my wishes certainly would make me a country clergyman." (Gertrude Himmelfarb, Darwin and the Darwinian Revolution [New York: W. W. Norton, 1959], 64-65, 459.) The quotation from Bowler is from Peter J. Bowler, Evolution: The History of an Idea, Revised Edition (Berkeley: University of California Press, 1989), 246. The scientific opposition to Darwin's theory is described in David Hull's Darwin and His Critics: The Reception of Darwin's Theory of Evolution by the Scientific Community (Chicago: University of Chicago Press, 1983), while the broad spectrum of nineteenth-century religious opposition to Darwin is described in James R. Moore's The Post-Darwinian Controversies (Cambridge: Cambridge University Press, 1979). There is no historical evidence for Darwin's shipboard reaction to FitzRoy's Bible reading. According to Himmelfarb (64), Darwin was "shocked when one of his shipmates flatly denied the fact of the flood. Indeed, he was remembered by them as being naively orthodox in his beliefs. Several of the officers (though themselves orthodox) were amused once when he unhesitatingly gave the Bible as final authority on a debated point of morality." Further details of Darwin's life can be found in Adrian Desmond and James Moore, Darwin: The Life of a Tormented Evolutionist (New York: W.W. Norton, 1991).
Some other quotes from Dennett's book (after which this episode is named) are: Darwin's dangerous idea cuts much deeper into the fabric of our most fundamental beliefs than many of its sophisticated apologists have yet admitted, even to themselves. (18) To put it bluntly but fairly, anyone today who doubts that the variety of life on this planet was produced by a process of evolution is simply ignorant--inexcusably ignorant. (46) Evolutionists who see no conflict between evolution and their religious beliefs have been careful not to look as closely as we have been looking, or else hold a religious view that gives God what we might call a merely ceremonial role to play. (310) Those whose visions dictate that they cannot peacefully coexist with the rest of us we will have to quarantine as best we can. . . . If you insist on teaching your children falsehoods--that the Earth is flat, that `Man' is not a product of evolution by natural selection--then you must expect, at the very least, that those of us who have freedom of speech will feel free to describe your teachings as the spreading of falsehoods, and will attempt to demonstrate this to your children at the earliest opportunity. Our future well-being--the well-being of all of us on this planet--depends on the education of our descendants. What, then, of all the glories of our religious traditions? They should certainly be preserved, as should the languages, the art, the costumes, the rituals, the monuments. (519) Dennett recommends that religion be "preserved in cultural zoos." His book concludes with: "Is something sacred? Yes, I say with Nietzsche. I could not pray to it, but I can stand in affirmation of its magnificence. This world is sacred." (520)
Darwin wrote in the second edition of his Journal of Researches (London: John Murray, 1845, 380): "The most curious fact is the perfect gradation in the size of the beaks of the different species of [finches]. Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends." But Darwin by then had already formulated his theory, so this was a speculative afterthought. Indeed, the confusion surrounding the geographical labeling of Darwin's specimens (alluded to in the PBS episode) made it impossible for him to use them as evidence for his theory. Nor did Darwin have a clear idea of the finches' ancestry. He did not visit the western coast of South America north of Lima, Peru, so for all Darwin knew the finches were identical to species still living on the mainland. It wasn't until the 1930s that the Galápagos finches were elevated to their current prominence. Although they were first called "Darwin's finches" by Percy Lowe in 1936 (Ibis 6: 310-321), it was ornithologist David Lack who popularized the name a decade later. Lack's 1947 book, Darwin's Finches (Cambridge University Press), summarized the evidence correlating variations in finch beaks with different food sources, and argued that the beaks were adaptations caused by natural selection. In other words, it was Lack more than Darwin who imputed evolutionary significance to the Galápagos finches. Ironically, it was also Lack who did more than anyone else to popularize the myth that the finches had been instrumental in shaping Darwin's thinking.
http://www.ncbi.nlm.nih.gov/htbin-post/Taxonomy/wprintgc?mode=c
Any engineer would naturally assume that the photocells would point towards the light, with their wires leading backwards towards the brain. He would laugh at any suggestion that the photocells might point away from the light, with their wires departing on the side nearest the light. Yet this is exactly what happens in all vertebrate retinas. Each photocell is, in effect, wired in backwards, with its wire sticking out on the side nearest to the light. The wire has to travel over the surface of the retina, to a point where it dives through a hole in the retina (the so-called `blind spot') to join the optic nerve. This means that the light, instead of being granted an unrestricted passage to the photocells, has to pass through a forest of connecting wires, presumably suffering at least some attenuation and distortion (actually probably not much but, still, it is the principle of the thing that would offend any tidy-minded engineer!). (p. 93) See also Timothy H. Goldsmith, "Optimization, Constraint, and History in the Evolution of Eyes," The Quarterly Review of Biology 65:3 (1990), 281-322. For a discussion of the role played in Darwinian thinking by hidden theological arguments (like the argument that God would only make perfect things), see Paul A. Nelson, "The Role of Theology in Current Evolutionary Reasoning," Biology and Philosophy 11 (1996), 493-517; and Cornelius George Hunter, Darwin's God (Grand Rapids, MI: Brazos Press, 2001). For arguments against the modern Darwinian claim that the vertebrate eye is imperfect, see George Ayoub, "On the Design of the Vertebrate Retina," Origins and Design 17:1 (1997), available at: http://www.arn.org/docs/odesign/od171/retina171.htm See also Michael J. Denton, "The Inverted Retina: Maladaptation or Pre-adaptation?" Origins and Design 19:2 (1997), available at: http://www.arn.org/docs/odesign/od192/invertedretina192.htm For general background on the evolution of eyes, see L. Salvini-Plawen and Ernst Mayr, "On the Evolution of Photoreceptors and Eyes," Evolutionary Biology 10 (1977), 207-263. Neuroanatomist Bernd Fritzsch, though an evolutionist, criticizes over-simplified explanations for the evolution of the vertebrate eye in "Ontogenetic Clues to the Phylogeny of the Visual System," in The Changing Visual System, edited by P. Bagnoli and W. Hodos (New York: Plenum Press, 1991), 33- 49. For a published report of Nilsson's work, see Dan-Eric Nilsson and Susanne Pelger, "A pessimistic estimate of the time required for an eye to evolve," Proceedings of the Royal Society of London B 256 (1994), 53-58. See also Richard Dawkins, "The eye in a twinkling," Nature 368 (1994), 690-691. The lack of a Darwinian explanation for the origin of light-sensitive cells is discussed in Michael J. Behe, Darwin's Black Box (New York: Simon & Schuster, 1996), Chapter 1.
For more on Kenneth Miller's views, see his book, Finding Darwin's God (New York: Cliff Street Books, 2000).
Darwinists sometimes claim that it was Darwin who showed that humans are part of nature. But that was never in doubt. Aristotle discusses emotions that humans share with animals in his History of Animals, 488b12-20, 508a19-22, 571b9-11, 575a20-32, 581b12-21, 585a3-4, 588a22-31, 608a11-608b18, 629b6-8, and 630b18-23. Catholic theologian and philosopher Thomas Aquinas discusses the animal nature of human beings in the Summa Theologiae, First Part ("Treatise on Man") and First Part of the Second Part ("Treatise on the Divine Government"). In the eighteenth-century, Swedish biologist Carolus Linnaeus classified humans and apes together in one taxonomic family. For Aquinas and Linnaeus, however, the similarities between humans and other animals came from a common creator, not a common ancestor. The issue here is not whether humans have an animal nature, but whether humans are just animals. |
