Why Darwin Matters Read online

  Observation. Science and technology have changed our world more in the past century than it changed in the previous hundred centuries—it took ten thousand years to get from the cart to the airplane, but only sixty-six years to get from powered flight to a lunar landing. Moore’s Law of computer power doubling every eighteen months continues unabated and is now down to about a year. Some computer scientists, such as Ray Kurzweil, calculate that there have been thirty-two doublings since World War II, and that as early as 2030 we may encounter the Singularity—the point at which total computational power will rise to levels that are so far beyond anything that we can imagine that they will appear near infinite and thus, relatively speaking, be indistinguishable from omniscience (note the suffix!).6 When this happens the world will change more in a decade than it did in the previous thousand decades.

  Deduction. Extrapolate these trend lines out a hundred thousand years, or a million years (an eye blink on an evolutionary time scale, and thus a realistic estimate of how far advanced an ETI will be7), and we get a gut-wrenching, mind-warping feel for just how godlike an ETI would appear to us.

  By pursuing a course of inquiry to its natural end, Intelligent Design, as a simplistic scientific explanation of the world around us, can only lead to the discovery of Extra-Terrestrial Intelligence. What Intelligent Design advocates will find (if they find anything) is an alien being capable of engineering DNA, cells, complex organisms, planets, stars, galaxies, and perhaps even universes. If today we can engineer genes, clone mammals, and manipulate stem cells with science and technologies developed in only the last half century, think of what an ETI could do with one hundred thousand years of equivalent powers of progress in science and technology. For an ETI who is a million years more advanced than we are, engineering the creation of planets and stars will probably be practicable. And if universes are created out of collapsing black holes—which some cosmologists think is probable—it is not inconceivable that a sufficiently advanced ETI could even create a universe.

  What would we call an intelligent being that could engineer a universe, stars, planets, and life? If we knew the underlying science and technology used to do the engineering, we would call it an ETI; if we did not know the underlying science and technology, we would call it an Intelligent Designer; if we left science out of theology altogether, we would call it God.

  So Intelligent Design is simple science. It is also bad theology: Intelligent Design reduces the deity to a mere engineer, a garage tinkerer, a technician piecing together worlds and life forms out of available materials, but not necessarily the creator of the original materials. This is not at all the spirit invoked in creeds such as those formulated at the first Nicene Council, held in AD 325, the opening of which states: “We believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible.”

  In his classic work, Maker of Heaven and Earth, the Protestant theologian Langdon Gilkey, who also penned a cogent history of the 1981 Arkansas creationism trial,8 rejects the approach taken by the natural theologians all the way back to William Paley’s heyday. “In the Christian doctrine of creation,” he writes, “God is the source of all and creates out of nothing. Thus the Christian idea, far from merely representing a primitive anthropomorphic projection of human art upon the cosmos, systematically repudiates all direct analogy from human art.” Far from being a mere intelligent watchmaker, God is the “transcendent source of all existence” who creates ex nihilo—from nothing. For Gilkey, whose theology I greatly respect, knowledge of God comes “not from a careful scientific or metaphysical analysis of the general experience of nature and of finite existence, but rather from the illumination that comes from special encounters with God in revelatory experiences.”9

  Recall that in our study on why people believe in God, the second most popular reason people gave for their belief was the experience of God in everyday life. This reason, and not the convoluted logic and twisted science of Intelligent Design Creationism, makes for deep and honest theology, the type of theology practiced by the great German theologian Paul Tillich, who once said, “God does not exist. He is being itself beyond essence and existence. Therefore to argue that God exists is to deny him.”10

  If we think of God as a thing, a being that exists in space and time, it constrains God to our world, a world of other things and other beings that are also restrained by the laws of nature and the contingencies of chance. But if God is the maker of all things and all beings visible and invisible in heaven and earth, God must be above such restraints; that is, above the laws of nature and contingencies of chance. “The question of the existence of God can be neither asked nor answered,” Tillich explains. “If asked, it is a question about that which by its very nature is above existence, and therefore the answer—whether negative or affirmative—implicitly denies the nature of God. It is as atheistic to affirm the existence of God as it is to deny it. God is being-itself, not a being.”11

  If there is a God, the avenue to Him is not through science and reason, but through faith and revelation. If there is a God, He will be so wholly Other that no science can reach Him, especially not the science that calls itself Intelligent Design.

  DEBATING INTELLIGENT DESIGN

  Those who cavalierly reject the Theory of Evolution, as not adequately supported by facts, seem quite to forget that their own theory is supported by no facts at all.

  —Herbert Spencer, Essays Scientific, Political and Speculative, 1891

  Debating creationists on the “science,” rather than the theology, of Intelligent Design is problematic, and I have been encouraged not to do so by such friends and colleagues as Stephen Jay Gould and Richard Dawkins, whose wisdom I consider inestimable. They argue, correctly, that there is no debate about the reality of evolution—the issue was settled a century ago—and that the numerous debates about how evolution happened are all well within the normal borders of science. In any case, public debate is not how the validity of a scientific theory is determined, and participating in a debate could send the wrong message to the public: that evolution is debatable.

  But eschewing public debate has not kept the Intelligent Design movement at bay, nor has the public decided that evolution should not be debated. On a balmy spring Southern California evening in 2004, for example, I entered the four-hundred-seat Physical Sciences Lecture Hall on the campus of the University of California, Irvine, to find it chockablock with five hundred people. I was there to debate the incorrigibly insouciant Kent Hovind, Young Earth Creationist, Defender of the Fundamental Faith, and the fastest talker I have ever met. On the docket that evening was the defining question of this controversy, Creation vs. Evolution: Creation (supernatural action) or Evolution (natural processes)—which is the better explanation? So, in contrast to many other scientists, I believe there are legitimate and important reasons to engage in the debate between evolution and Intelligent Design:

  1. Debates will occur anyway, so they might as well include someone with expertise and experience in science. Better still if they also have expertise and experience in debating, and can employ diplomacy, wit, and warmth along with scientific facts.

  2. When a controversy receives as much media attention as evolution and creationism have garnered over the past century, refusing to engage in public dialogue or debate can be misconstrued as a weakness in one’s position. Intelligent Design advocates have made a cottage industry out of exactly this point.

  3. Debate forces both sides to put their cards face up on the table for everyone to see. Intelligent Design creationists have no science to speak of, and debates provide opportunities to demonstrate that a pretty PowerPoint slide is not science. As John Stuart Mill argued in his classic 1859 treatise On Liberty: “But the peculiar evil of silencing the expression of an opinion is, that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the oppo
rtunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error.”1

  4. Debate is a chance to educate people about science and evolution. As we have discussed, muddled misunderstandings about the science of evolution—and the theology of Intelligent Design—far outnumber concrete understanding. In general, the world may be divided into three types of people: True Believers, Fence Sitters, and skeptics. Religious True Believers will never change their minds no matter what evidence is presented to them, and science-embracing skeptics already accept evolution. The battleground is for the Fence Sitters—those who have heard something about a claim or controversy and wonder what the explanation for it might be. Lacking a good explanation, the mind defaults to whatever explanation is on the table, regardless of how improbable it may be.

  Point four is particularly relevant to the debate between evolution and Intelligent Design. Before the theory of evolutionary biology was developed in the nineteenth century, the default explanation for the distribution of species around the globe was independent creation by God and the Noachian flood. (Among the handful of more religiously skeptical scientists, the mode of distribution was Lamarckian evolution and long-gone land bridges between continents and islands.) But after Charles Darwin and Alfred Russel Wallace demonstrated how natural selection changes varieties into different species when they migrate into different regions, the default supernatural explanation could be abandoned in favor of a fact-based natural one. Debate affords us an occasion to demonstrate to Fence Sitters that there is, in fact, a perfectly reasonable natural explanation for the apparently supernatural phenomenon of design.2

  Investigating Intelligent Design

  Skepticism—thoughtful inquiry—is a scientific way of thinking; science—a testable body of knowledge—is applied skepticism. At the core of any scientific investigation are a number of skeptical principles that help us assess the validity of a claim before we examine the specific arguments and evidences. Six principles of skepticism help us sort through the various arguments for Intelligent Design:

  Hume’s Maxim, or, what is more likely?

  In 1758 the Scottish philosopher David Hume published his most influential work, An Enquiry Concerning Human Understanding. When confronted by the claim of an event so improbable and extraordinary that it is called a miracle, Hume asks us to inquire what is more likely: that a supernatural act occurred contrary to the laws of nature, or that people who describe such acts are mistaken in their assessment of the event’s supernatural nature? Hume’s Maxim is best defined in his own words: “The plain consequence is (and it is a general maxim worthy of our attention), ‘That no testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous than the fact which it endeavours to establish.’ ”

  Hume then weighs which is more likely: “When anyone tells me that he saw a dead man restored to life, I immediately consider with myself whether it be more probable, that this person should either deceive or be deceived, or that the fact, which he relates, should really have happened. I weigh the one miracle against the other; and according to the superiority, which I discover, I pronounce my decision, and always reject the greater miracle. If the falsehood of his testimony would be more miraculous than the event which he relates; then, and not till then, can he pretend to command my belief or opinion.”3

  The evolution–Intelligent Design debate boils down to a Humean question of what’s more likely: that the diversity and complexity of life we see around us came about by laws of nature that we can observe, or supernaturally by an Intelligent Designer that we cannot observe? The nineteenth-century social Darwinist Herbert Spencer answered the question rhetorically: “Well, which is the most rational theory about these ten millions of species? Is it most likely that there have been ten millions of special creations? or is it most likely that, by continual modifications due to change of circumstances, ten millions of varieties have been produced, as varieties are being produced still?”4 It’s a good question.

  The Known and the Unknown, or, before you say something is out of this world, first make sure it is not in this world.

  Creationists and Intelligent Design theorists explain natural phenomena by turning immediately to supernatural forces operating outside this world. Following that thinking, there is no point in searching for medical cures in the natural world; we should throw out all medical knowledge and turn purely to prayer, without trying any treatments. But medicine, like evolution and other sciences, deals with natural explanations for natural phenomena, and even with only a rudimentary understanding of the natural world we should seek answers from the known, natural world first. Before assuming that the unknown is the only possible way to account for the complexity and diversity of life, it must first be demonstrated that known forces and processes cannot do the job.

  Burden of Proof, or, extraordinary claims require extraordinary evidence.

  Darwin’s original claim of evolution by means of natural selection was an extraordinary claim in its time, so he was required to provide extraordinary evidence for it. He did, and evidence has continued accumulating ever since. Today, the burden of proof is on creationists and Intelligent Design advocates to provide extraordinary evidence for their extraordinary claim that a supernatural being of great power and intelligence performed a supernatural act in place of or contrary to natural law. They have yet to do so.

  Either-Or Fallacy, or, disproving A does not prove B.

  The either-or fallacy is the false assumption that there are only two positions, A and B, so if A is wrong then B must be right. The fallacy is that discrediting A does not demonstrate B. Both A and B could be wrong and a third alternative could be correct. Creationists employ the either-or fallacy when they claim that life was either divinely created or naturally evolved. By attempting to discredit evolution they hope to draw the conclusion that creationism is true. In science, however, it is not enough to just debunk the accepted theory. You must also replace it with a theory that explains both the “normal” data accounted for by the old theory as well as some of the “anomalous” data not accounted for by the old theory. At the end of my debate with Kent Hovind, for example, he was asked by an audience member: “What is the best evidence for the creation?” He answered: “The impossibility of the contrary” (that is, evolution). In that simple statement, Hovind confessed the scientific sin of creationism and Intelligent Design: Disproving evolution does not prove creationism.

  The Fossil Fallacy, or, one datum does not a science make.

  In debates with creationists they often demand “just one transitional fossil” that proves evolution, pointing to a gap in the fossil record. When I fill the gap—for example, with Ambulocetus natans, a transitional fossil between ancient land mammals and modern whales—they respond that there are now two gaps in the fossil record! This is a clever retort, but it reveals a deep error in epistemology that I call the Fossil Fallacy: the belief that a single “fossil”—one bit of data—constitutes proof of a multifarious process or historical sequence.5

  Proof is derived not through a single piece of evidence, but through that convergence of evidence from numerous lines of inquiry, all of which point to an unmistakable conclusion. We know evolution happened not because of a single transitional fossil such as Ambulocetus natans, but because of the convergence of evidence from such diverse fields as geology, paleontology, biogeography, comparative anatomy and physiology, molecular biology, genetics, and many more. Paleontologist Donald Prothero, for example, employs the convergence technique in revealing that in addition to at least eight transitional fossils from land mammals to whales, DNA from living specimens reveals that modern whales descended from even-toed hoofed mammals called artiodactyls. Whales, it turns out, are most closely related to the hippopotamus.6

  No single discovery from any one field constitutes proof of evolution. It i
s the mass of data together, converging to reveal that life evolved in a specific sequence by a particular process, that makes the theory of evolution a singular landmark in our understanding of the world.

  Methodological Naturalism, or, no miracles allowed.

  In one of Sidney Harris’s most poignant cartoons, two scientists are at a blackboard filled with equations, in which the words “THEN A MIRACLE OCCURS” appear in the middle. The caption has one scientist saying to the other: “I THINK YOU NEED TO BE MORE EXPLICIT HERE IN STEP TWO.” This is what we call the God of the Gaps argument—wherever an apparent gap exists in scientific knowledge, this is where God interjects a miracle. Intelligent Design advocates argue something like this:

  • X looks designed

  • I can’t think of how X could have been designed naturally

  • Therefore X must have been designed supernaturally

  This is comparable to the “plane problem” of Isaac Newton’s time: The planets all lie in a plane (the plane of the ecliptic) and revolve about the sun in the same direction. Newton found this arrangement to be so improbable that he invoked God as an explanation at the end of his magisterial work Principia Mathematica: “This most beautiful system of the sun, planets, and comets could only proceed from the counsel and dominion of an intelligent and powerful Being.”7 Why don’t creationists use this argument any more? Because astronomers have filled that gap with a natural explanation.

  The technical term for this process is methodological naturalism, and Intelligent Design theorists harp about it incessantly. Methodological naturalism holds that life is the result of natural processes in a system of material causes and effects that does not allow, or need, the introduction of supernatural forces. In his book Darwin on Trial, University of California, Berkeley, law professor Phillip Johnson, the founding father of the Intelligent Design movement, accused scientists of unfairly defining God out of the picture by limiting the search to only natural causes, and argued that scientists who postulate that there are supernatural forces or interventions at work in the natural world are being pushed out of the scientific arena on the basis of nothing more than a fundamental rule of the game. Johnson wants the rules of the game changed to allow methodological supernaturalism.