Why Darwin Matters Read online

  Okay, let’s change the rules. Let’s allow methodological supernaturalism into science. What would that look like? How would that work? What would we do with supernaturalism? For the sake of argument, let’s assume that Intelligent Design theorists have suddenly become curious about how exactly the Intelligent Designer operates. As researchers who are now given entrée into the scientific stadium with an addendum to the rules that allows supernaturalism, they call a time out during the game to announce, “THEN A MIRACLE OCCURS.” What do we do now? Do we halt all future experiments? Since science is what scientists do, what are we supposed to do with such supernatural explanations? My response to the God of the Gaps argument is: “I THINK YOU NEED TO BE MORE EXPLICIT HERE IN STEP TWO.”

  Even if Intelligent Design advocates are willing to continue searching, what will they do if they discover a new force of nature that accounts for design? How will they identify it? Will it be considered a natural force, or a supernatural force? When electromagnetism and the weak and strong nuclear forces were discovered in the nineteenth and twentieth centuries, scientists did not identify them as supernatural forces; they simply added them to the known forces of nature. If IDers eschew all attempts to provide a naturalistic explanation for life, they abandon science altogether.8

  There is no such thing as the supernatural or the paranormal. There is only the natural, the normal, and mysteries we have yet to explain.

  Intelligent Design’s Best Arguments

  As we have seen, creationists and Intelligent Design theorists have made dozens of arguments trying to disprove evolution, most hinging on the truly meaningless search for a single piece of data that will fill the gap of the week. But much of their recent success in classrooms and with school boards has been in using the language of science to argue that the data support Intelligent Design rather than evolution. Here I present their ten most cogent—and most commonly presented—arguments, followed by an evolutionary response grounded in the latest scientific theories on the origin and evolution of the universe and life.9

  The Anthropic Principle:

  The universe is fine tuned for life.

  We begin with what I consider to be the best scientific argument that creationists and Intelligent Design theorists have in their arsenal: The universe is finely tuned and delicately balanced to support life. Change any number of physical parameters or initial conditions of the universe by even the tiniest amount, and life would not be possible. Fine tuning implies that there is a fine tuner, an Intelligent Designer, a God.

  There is no shortage of observations from leading scientists on this condition of the cosmos. No less a personage than Stephen Hawking wrote:

  Why is the universe so close to the dividing line between collapsing again and expanding indefinitely? In order to be as close as we are now, the rate of expansion early on had to be chosen fantastically accurately. If the rate of expansion one second after the big bang had been less by one part in 1010, the universe would have collapsed after a few million years. If it had been greater by one part in 1010, the universe would have been essentially empty after a few million years. In neither case would it have lasted long enough for life to develop. Thus one either has to appeal to the anthropic principle or find some physical explanation of why the universe is the way it is.10

  What is this supernaturally appealing “anthropic principle”? In The Anthropic Cosmological Principle, the physicists John Barrow and Frank Tipler define the term: “It is not only man that is adapted to the universe. The universe is adapted to man. Imagine a universe in which one or another of the fundamental dimensionless constants of physics is altered by a few percent one way or the other. Man could never come into being in such a universe. That is the central point of the anthropic principle. According to the principle, a life-giving factor lies at the center of the whole machinery and design of the world.”11 Of course, thinking of man as the center of the universe has not had a strong track record in science, but let’s set aside Copernican reservations in favor of contemporary astronomy.

  Sir Martin Rees, Britain’s Astronomer Royal, argues that “our emergence from a simple Big Bang was sensitive to six ‘cosmic numbers.’ Had these numbers not been ‘well tuned,’ the gradual unfolding of layer upon layer of complexity would have been quenched.”12 The six cosmic numbers are:

  Ω (omega) = 1, the amount of matter in the universe, such that if Ω was greater than one, it would have collapsed long ago, and if Ω was less than one, no galaxies would have formed.

  ε (epsilon) = .007, how firmly atomic nuclei bind together, such that if epsilon were .006 or .008, matter could not exist as it does.

  D = 3, the number of dimensions in which we live, such that if D were 2 or 4, life could not exist.

  N = 1036, the ratio of the strength of gravity to that of electromagnetism, such that if it had just a few less zeros, the universe would be too young and too small for life to evolve.

  Q = 1/100,000, the fabric of the universe, such that if Q were smaller, the universe would be featureless, and if Q were larger, the universe would be dominated by giant black holes.

  λ (lambda) = 0.7, the cosmological constant, or “antigravity” force, that is causing the universe to expand at an accelerating rate, such that if λ were larger, it would have prevented stars and galaxies from forming.

  Change these relationships and stars, planets, and life could not exist. Thus, this is not just the best of all possible worlds, it is the only possible world—and a world crafted with remarkable math skills, to boot. Intelligent Design theorists consider these numbers to be complex and specified, and thus the fine-tuned anthropic principle is evidence of design.13

  First, the universe is not so finely tuned for life. The vast majority of the universe is empty space, and the vast majority of what little matter there is, is completely inhospitable to life, including most planets. In its 13.7-billion-year history, the anthropic conditions for life were nonexistent for several billion years—it is only during a narrow slice of recent time that the universe became finely tuned for life, and only a minuscule portion of the universe is hospitable. John Barrow and his colleague John Webb also note that the so-called “constants” of nature—the speed of light, gravitation, the mass of the electron—may be inconstant, varying over time from the Big Bang to the present, making the universe finely tuned only now. 14

  Second, our universe is not finely tuned for us (the strong anthropic principle), we are finely tuned for it (the weak anthropic principle). It is entirely possible that a completely different form of life could be based on another type of physics. We are carbon chauvinists, Carl Sagan liked to point out; life based on some other element (such as silicon) is entirely possible, but because we know of only one type, it is difficult for us to think outside the chemical box.

  Third, our universe may not be that exceptional. String theory, for example, allows for 10500 possible worlds, all with different selfconsistent laws and constants.15 That’s a 1-followed-by-500-zeros possible universes (recall that twelve zeros is a trillion!). If that is true, it would be miraculous if there were not intelligent life in a number of them. The physicist and astronomer Victor Stenger created a computer model that analyzes what just a hundred different universes would be like under constants different from our own, ranging from five orders of magnitude above to five orders of magnitude below their values in our universe. He discovered that longlived stars of at least one billion years—necessary for the production of life-giving heavy elements—would emerge within a wide range of parameters in at least half of the universes in his model.16

  Fourth, there may be an underlying principle behind all the finetune equations and relationships that will be forthcoming when the grand unified theory of physics is discovered. In the grand unified theory there will not be six mysterious numbers, there will be just one. Here we would do well to remember skeptical principle number two: Before you say something is out of this world, first make sure it is not in this world. Until we hav
e a unified theory of physics connecting the quantum world of subatomic particles to the cosmic world of general relativity, we cannot conclude that there is something beyond nature to explain the anthropic principle.

  Fifth, we may live in a multiverse, in which our universe is just one of many bubble universes, all with different laws of nature. Those with physical parameters like ours are more likely to generate life. Cosmologists theorize that there may even be a type of natural selection at work among the many bubble universes, in which those whose parameters are like ours are more likely to survive. According to inflationary cosmology, each time a black hole collapses, it does so into a singularity—the same entity out of which our universe may have sprung. Every time a star collapses into a black hole in our universe, the “other side” of the black hole may yield a new baby universe. Since there have likely been billions of collapsed black holes, there could be billions of bubble universes. Those universes whose initial conditions and physical laws do not produce stars like ours will not have black holes and thus will not reproduce more life-giving universes. Those bubble universes whose parameters are like ours are more likely to give rise to universes with life, perhaps even complex life with brains big enough to conceive of God and evolution.17 How elegantly recursive!

  In a slightly different scenario—one in which the universe is created out of a fluctuation in the quantum foam of space (it turns out that space is not so empty at the quantum level and that pure energy may give rise to matter)—Stephen Hawking answered the anthropic principle problem by conjecturing that new baby universes may be created in the same manner: “Quantum fluctuations lead to the spontaneous creation of tiny universes, out of nothing. Most of the universes collapse to nothing, but a few that reach a critical size, will expand in an inflationary manner, and will form galaxies and stars, and maybe beings like us.”18 Indeed, the multiverse is the next natural step in our expanding knowledge of the cosmos: from the earth to the solar system to the galaxy to the universe to the multiverse; that is, from the Copernican revolution that overturned the medieval worldview with the earth at the center and the stars and planets rotating close by on their crystal spheres and created within the last ten thousand years, to the early-modern worldview of the Milky Way galaxy as the entire known universe created within the last several million years, to the modern worldview of an accelerating expanding universe of some 13.7 billion years of age, to a multiverse of perhaps infinite age and containing perhaps an infinite number of universes.

  Finally, from what we now know about the cosmos, to think that all this was created for just one species among tens of millions of species who live on one planet circling one of a couple of hundred billion stars that are located in one galaxy among hundreds of billions of galaxies, all of which are in one universe among perhaps an infinite number of universes all nestled within a grand cosmic multiverse, is provincially insular and anthropocentrically blinkered. Which is more likely? That the universe was designed just for us, or that we see the universe as having been designed just for us?

  The Design Inference: There is a distinct difference between objects that are naturally designed and those that are intelligently designed.

  Mount Rushmore is made entirely of natural material (rock), but no one would infer that the natural forces of erosion account for the design of four U.S. presidents’ faces on the granite. This is an example of what Intelligent Design theorists call a “design inference,” another staple argument, this one with its roots in lutemakers and William Paley’s watchmakers. Of course, there are lots of examples of natural forces that do account for designed-looking objects: the rock formation in Maui’s Iao Valley State Park that bears a striking resemblance to President John F. Kennedy in profile; the eroded mountain on Mars that under coarse-grained resolution looks like a face; the eagle rock off the 134 freeway in Southern California that overlooks the town of Eaglerock; the “Nun Bun” found by a Tennessee baker that resembles Mother Teresa; the Virgin Mary stained on the side of a bank building in Clearwater, Florida, or on a Chicago freeway underpass, or on a cheese sandwich in a Las Vegas casino. Although they were created entirely by natural forces, almost no one infers that there is an Intelligent Designer behind such artifacts of nature (with the possible exception of the Virgin Mary stains, which some religious devotees regard as miraculous apparitions). How can we tell the difference between natural design and artificial design?

  “Design theorists infer a prior intelligent cause based upon present knowledge of cause-and-effect relationships,” writes the philosopher of science and Intelligent Design advocate Stephen Meyer. “Inferences to design thus employ the standard uniformitarian method of reasoning used in all historical sciences, many of which routinely detect intelligent causes.” Archaeologists, for example, employ statistical and physical criteria to discriminate between natural-made and human-made artifacts, so it is fair to say that “intelligent agents have unique causal powers that nature does not. When we observe effects that we know only agents can produce, we rightly infer the presence of a prior intelligence even if we did not observe the action of the particular agent responsible.”19 Intelligent Design theorists point to the elegance, uniformity, and ingenuity of DNA: It is no more naturally designed than the pyramids. If it looks intelligently designed, it was.

  But the inference to design is subjective. Sometimes it is obvious, other times it is not. The difference between a rock and a watch is obvious; the difference between a rock and a chipped-stone tool made by an Australopithecene three million years ago is not obvious. And the inference to design is specific to each claim. In the chippedstone problem, for example, a rock that has been chipped on both sides in a symmetrical fashion is more likely to be intelligently designed than naturally flaked. Nevertheless, archaeologists admit that they likely infer false positives, and there is no surefire design inference algorithm that applies to all archaeological problems, let alone one that applies to all scientific fields. The set of criteria used by archaeologists to determine whether a stone was chipped by chance or design is completely different from the set of criteria used by astronomers to determine whether a signal from space is natural or artificial.

  Second, we perceive nature to be intelligently designed based on our experience of human artifacts. We know some human artifacts are intelligently designed because we have observed them being made and we have vast experience with human artificers. By contrast, we have no experience with a nonhuman intelligent designer, and no experience with a supernatural agent—outside of inferring that one exists by identifying the current gaps in our knowledge of apparently designed objects. The skeptical principle, Methodological Naturalism, or, no miracles allowed, refutes the inference to supernatural intelligent design. Not yet understanding how something was created naturally does not make it a supernatural creation.

  Last, we must be cautious about inferring design because our experience with intelligently designed artifacts in our culture biases us to see intelligent design where none exists (for example, those Virgin Mary apparitions). Long before Darwin debunked the watchmaker argument, the Enlightenment philosopher Voltaire satirized this problem in his classic novel Candide, through the character Dr. Pangloss, a professor of “metaphysico-theology-cosmolonigology”: “’Tis demonstrated that things cannot be otherwise; for, since everything is made for an end, everything is necessarily for the best end. Observe that noses were made to wear spectacles; and so we have spectacles. Legs were visibly instituted to be breeched, and we have breeches.”20

  Explanatory Filter: A tool for discriminating between natural design and intelligent design shows that only an Intelligent Designer can account for complex specified information and design.

  Mathematician William Dembski has devised an “Explanatory Filter” through which intelligent design can be distinguished from natural design. Dembski asks, “When called to explain an event, object, or structure, we have a decision to make—are we going to attribute it to necessity, chance, or design?”2
1 If necessity (natural law) and chance (randomness) cannot explain the phenomenon, then design (intelligence) is the default answer. The filter operates in a three-step process:

  1. Does natural law explain the design? If event E has a high probability, accept necessity as an explanation; otherwise move to the next step.

  2. Does chance explain the design? If event E has an intermediate probability or E is not specified, then accept chance; otherwise move to the next step.

  3. Does intelligent design explain the design? Having eliminated necessity and chance as the explanation for a highly specified but low probability event, accept design.22

  The Explanatory Filter is a tool by which we can tell the difference between the naturally designed JFK rock formation and the intelligently designed Mount Rushmore rock formation: “I argue that the Explanatory Filter is a reliable criterion for detecting design,” Dembski explains. “Alternatively, I argue that the Explanatory Filter successfully avoids false positives. Thus, whenever the Explanatory Filter attributes design, it does so correctly.”23