The Greatest Show on Earth: The Evidence for Evolution by Richard Dawkins is the famous biologist’s most recent book since his best selling The God Delusion. This is a well-written book, complete with illustrations and beautiful color sections. In it, Professor Dawkins presents evidence for evolution. The purpose of this review is to survey some of Dawkins’ ideas and weigh up the overall logic of his case for evolution; in particular, does Dawkins present a good case that macroevolution is a fact?
Dawkins states his purpose for the book clearly from the outset: “This book is my personal summary of the evidence that the ‘theory’ of evolution is actually a fact – as incontrovertible a fact as any in science.” (vii) The author’s thesis is to present the evidence for those who doubt evolution, and to equip those who are frustrated with those who doubt evolution. Dawkins is passionately against the ignorance of those who would doubt what he sees as indisputable fact, referring to them as “history-deniers”:
I shall be using the name ‘history-deniers’ for those people who deny evolution: who believe the world’s age is measured in thousands of years rather than thousands of millions of years, and who believe humans walked with dinosaurs. (7)
Dawkins seems to place all doubters into the young-earth category, while the illustrations he employs put them on par with “well-financed and politically muscular groups of Holocaust-deniers.” (4) Yet the author’s goal is partially to reach this very group: “The history-deniers themselves are among those that I am trying to reach in this book.” (8) His thesis:
Evolution is a fact. Beyond reasonable doubt, beyond serious doubt, beyond sane, informed, intelligent doubt, beyond doubt evolution is a fact. The evidence for evolution is at least as strong as the evidence for the Holocaust, even allowing for eyewitnesses to the Holocaust. (8)
We know this because of a rising flood of evidence supports it. Evolution is a fact, and this book will demonstrate it. No reputable scientist disputes it, and no unbiased reader will close the book doubting it. (8-9)
Like any good author, Dawkins first seeks to define some key terms in his thesis before presenting his case. In his preliminary definitions, Dawkins is careful to define the word theory. He is also careful to define the word fact; after all, his key thesis is to demonstrate that evolution is a fact:
Fact: Something that has really occurred or is actually the case; something certainly known to be of this character; hence, a particular truth known by actual observation or authentic testimony, as opposed to what is merely inferred, or to a conjecture or fiction; a datum of experience, as distinguished from the conclusions that may be based upon it. (14)
Dawkins cites this definition from Oxford English Dictionary. An Oxford man himself, Dawkins feels it appropriate to take some liberties of his own with the definition:
The implied pejorative of that ‘merely’ is a bit of a cheek. Careful inference can be more reliable than ‘actual observation’, however strongly our intuition protests at admitting it. (15)
This book will take inference seriously – not mere inference but proper scientific inference – and I shall show the irrefragable power of the inference that evolution is a fact. (16)
It is interesting to note that Dawkins finds it necessary to alter the definition of the word fact ever so slightly so that it fits his own usage. The Oxford English Dictionary makes a clear distinction between facts and inference. But while Dawkins frets over the word “merely,” he seems to have missed the latter part of the definition that distinguishes facts from the conclusions that they are based upon.
Having overlooked that part of the definition, the author proceeds to assure the reader:
The aids to inference that lead scientists to the fact of evolution are far more numerous, more convincing, more incontrovertible, than any eye-witness reports that have ever been used, in any court of law, in any century, to establish guilt in any crime. Proof beyond reasonable doubt? Reasonable doubt? That is the understatement of all time. (18)
Although the author did present the reader with definitions of a couple of key terms in his thesis, there seems to be a glaring omission: Dawkins never defines the word evolution. At best, the reader is left with a line fit for Yoda: “Evolution is within us, around us, between us, and its workings are embedded in the rocks of aeons past.” (18)
In fact, throughout the book the word evolution is used so liberally, and in such a wide variety of ways, it seems to lose all clarity. So for the sake of this review, evolution will be defined very roughly in two common senses: microevolution and macroevolution. Microevolution can be defined as small-scale changes over short generations. Macroevolution can be defined as large-scale changes over a geological time period. As there is little dispute over microevolution, this reviewer is most concerned with the evidence for macroevolution; proof that all living things are descended from a common ancestor.
Dawkins begins his presentation of evidence in chapter two, in which he explains the artificial breeding of “dogs, cows, and cabbages.” His overall goal seems to be to illustrate natural selection, which is a fact. Through selective breeding, humans can artificially “sculpt” the gene pool of various species, to which Dawkins imagines: “If so much evolutionary change can be achieved in just a few centuries or even decades, just think what might be achieved in ten or a hundred million years.” (37)
Dawkins’ reiterates his a fortiori argument:
If human breeders can transform a wolf into a Pekinese, or a wild cabbage into a cauliflower, in just a few centuries or millennia, why shouldn’t the non-random survival of wild animals and plants do the same thing over millions of years? (42)
This seems to be Dawkins’ first instance of assuming macroevolution to be true based upon evidence for microevolution. Yet Dawkins finds this evidence helpful to his case. Apparently he sees no limit to what could evolve naturally if given enough time.
Chapter three continues Dawkins’ exposition of natural selection. Here he shows how plants and flowers are selected over time by insects:
Insects may ‘breed’ flowers to be more beautiful, but not because they enjoy the beauty. Rather, the flowers benefit from being perceived as attractive by insects. The insects, by choosing the most attractive flowers to visit, inadvertently ‘breed for’ floral beauty. (53)
This chapter shows how selection, which was done in the earlier chapter artificially by man, is now taking place naturally, with plants and insects doing the selecting. Dawkins’ descriptions of the intricate pollination processes are indeed fascinating; the author’s love and admiration of nature truly shines through.
The fact of natural selection is in plain sight, which, of course, no one denies. However, Dawkins has some inferences to make from these facts:
The difference between any two breeds of dog gives us a rough idea of the quantity of evolutionary change that can be achieved in less than a millennium. The next question we should ask is, how many millennia do we have available to us in accounting for the whole history of life? If we imagine the sheer quantity of differences that separate a pye-dog from a peke, which took only a few centuries of evolution, how much longer is the time that separates us from the beginning of evolution or, say, from the beginning of mammals? … Can you imagine two million centuries, laid end to end? (81)
Dawkins sees the need to make extrapolations. Perhaps the reader wonders at this point if the author considers an extrapolation into the past a fact.
Bear in mind this order of evolutionary change, and then extrapolate backwards twenty thousand times as far into the past. It becomes rather easy to accept that evolution could accomplish the amount of change that it took to transform a fish into a human. (82)
Interested in finding out just how much time is available for past extrapolations, the book now turns the reader’s attention to the past:
If the history-deniers who doubt the fact of evolution are ignorant of biology, those who think the world began less than ten thousand years ago are worse than ignorant, they are deluded to the point of perversity. (85)
Here in chapter four Dawkins explains the various “clocks” that are available in nature to determine the time available for evolution to work, and “praise be, nature has provided us with just the wide range of clocks that we need.” (88) Of course, this chapter is also very interesting as it explores the ins and outs of dating, from tree rings to carbon dating.
Chapter five is entitled Before Our Very Eyes, and deals with examples of (micro) evolution happening right in front of us: “…some examples are so fast that we can see evolution happening with our own eyes during one human lifetime.” (111) Dawkins suggests: “Just think what you might see in three or four decades if you followed the evolution of bacteria, whose generations are measured in hours or even minutes, rather than years!” (116)
Here Dawkins explores the long-term experiments of Michigan State University bacteriologist Richard Lenski, which chart the generational changes of bacteria. Dawkins repeats his “how-much-more” reasoning here as well:
So, whatever evolutionary change Lenski may have clocked up in the equivalent of a million years of bacterial generations, think how much more evolution might happen in, say, 100 million years of mammal evolution. (119)
He seems to suggest that if you multiply the time available by a certain factor you can expect the observed changes to multiply in the same way; all while shifting his conclusions from bacteria to mammals. And here Dawkins produces what seems to be powerful genetic evidence from the Lenski experiments:
Lenski and a different set of colleagues investigated this phenomenon…which seemed, over 20,000 generations, to have followed the same evolutionary trajectory, and looking at their DNA. The astonishing result they found was that 59 genes had changed their levels of expression in both tribes, and all 59 had changed in the same direction. Were it not for natural selection, such independent parallelism, in 59 genes independently, would completely beggar belief. The odds against its happening by chance are stupefyingly large. This is exactly the kind of thing creationists say cannot happen, because they think it is too improbable to have happened by chance. Yet it actually happened. And the explanation, of course, is that it did not happen by chance, but because gradual, step-by-step, cumulative natural selection favoured the same – literally the same – beneficial changes in both lines independently. (124-125)
Michael Behe analyzed this same data in his 2007 book The Edge of Evolution, which explores the limits of evolutionary change. Behe suggested a different possibility of how fifty-nine genes could be affected in such a way:
Another change was in a regulatory gene called spoT which affected en masse how fifty-nine other genes worked, either increasing or decreasing their activity. One likely explanation for the net good effect of this very blunt mutation that it turned off the energetically costly genes that make the bacterial flagellum, saving the cell some energy. (Behe, 142)
Dawkins moves on in chapter six and seven to talk about fossils and missing links. But he doesn’t feel that fossils are necessary to prove evolution: “The evidence for evolution would be entirely secure, even if not a single corpse had ever fossilized.” (145) And again:
We don’t need fossils – the case for evolution is watertight without them; so it is paradoxical to use gaps in the fossil record as though they were evidence against evolution. (146)
Although Charles Darwin seemed to disagree on this point regarding the fossil record, Dawkins does however see them as useful: “In fact, for a large number of fossils, a good case can be made that every one of them is an intermediate between something and something else.” (151) He laments the fact that so many people want to see the “missing links,” and seems to turn much of his attention to attacking the “history-deniers” once again, answering such objections as “I’ll believe in evolution when a monkey gives birth to a human baby!”
Evolution not only is a gradual process as a matter of fact; it has to be gradual if it is to do any explanatory work. Huge leaps in a single generation – which is what a monkey giving birth to a human would be – are almost as unlikely as divine creation, and are ruled out for the same reason: too statistically improbable. It would be so nice if those who oppose evolution would take a tiny bit of trouble to learn the merest rudiments of what it is they are opposing. (155)
The author seems to be either completely unaware of, or unwilling to deal with, the actual scientific arguments of scientists such as Stephen Meyer or Michael Behe. Instead he spends his energies on crock-o-ducks and Noah’s Ark:
“Once again, I am sorry to take a sledgehammer to so small and fragile a nut, but I have to do so because more than 40 per cent of the American people believe literally in the story of Noah’s Ark.” (269)
Chapter eight is entitled You Did It Yourself in Nine Months. Here Dawkins cites an interaction between J.B.S. Haldane, a leading architect of neo-Darwinism, and an evolution skeptic. The skeptic poses a complex question of how, even given billions of years, a single cell could develop into a complicated human body that thinks and feels. Haldane’s one-liner response was, “But madam, you did it yourself. And it only took you nine months.”
What follows in this chapter is an exposition on embryology and how a single cell transforms into a complex living organism, which is of course fascinating. But Dawkins’ aim is to stress the idea that none of this is intentional or purposeful, even given the fact that it looks that way. Small bits are simply obeying local rules, from which eventually emerge complex bodies with the appearance of design:
They key point is that there is no choreographer and no leader. Order, organization, structure – these all emerge as by-products of rules which are obeyed locally and many times over, not globally. (220)
Dawkins stresses that we should not be deceived by the appearance of design; it is an illusion:
The body of a human, an eagle, a mole, a dolphin, a cheetah, a leopard frog, a swallow: these are so beautifully put together, it seems impossible to believe that the genes that program their development don’t function as a blueprint, a design, a master plan. But no…it is all done by individual cells obeying local rules. (220)
The author admits not only the appearance of design everywhere one looks, but he also uses design language and analogies throughout the entire book: “Notice, by the way, how hard it is to resist the language of intention, purpose and personification.” (351) The reader finds passages worthy of a modern-day Paley:
…the T4 bacteriophage, which parasitizes bacteria. It looks like a lunar lander, and it behaves rather like one, ‘landing’ on the surface of a bacterium (which is very much larger) then lowering itself on its spidery ‘legs,’ then thrusting a probe down the middle, through the bacterium’s cell wall, and injecting its DNA inside. (223)
Yet the reader is assured that Darwinian mechanisms are to be credited with this apparent design. The author asserts that Darwinism is to be credited for pretty much any form of life we could possibly hope to find in the future:
I love speculating on how weirdly different we should expect life to be elsewhere in the universe, but one or two things I suspect are universal, wherever life might be found. All life will turn out to have evolved by a process related to Darwinian natural selection of genes. (235)
In the next chapter, entitled The Ark of the Continents, Dawkins explores the diversity of species as explained by continental drift. Because all things share a common ancestor, there must come various points where they branch off and part ways.
What actually happened at this epic parting of the ways, nobody knows. It happened a very long time ago, and we have no idea where. But modern evolutionary theory would confidently reconstruct something like the following history. (255)
Dawkins admits that many of his details are strictly hypothetical fiction (256); but it doesn’t matter. It had to occur somehow, and he is merely offering options. Interestingly enough, this form of reasoning is the very thing he rails against later in the same chapter when referring to “…creationists’ penchant for ignoring evidence when it doesn’t support the position they know, from Scripture, has got to be true.” (283)
Chapter ten, The Tree of Cousinship, deals with homology. Bones and other structures are similar across a wide variety of animals. Included in this chapter are many line drawings of animals that look similar and have similar bone configurations. Molecular similarities are also included in Dawkins’ exposition. This, in the author’s opinion is strong evidence not only for microevolution, but macroevolution as well:
Anyway, the ancestors of whales and dolphins were fully paid-up land mammals, who surely galloped across the prairies, deserts or tundras with an up-and-down flexion of the spine. And when they returned to the sea, they retained their ancestral up-and-down spinal motion. (299)
In addition, he counts homology as evidence against any sort of design, asking the question, “Why would the designer not borrow that ingenious invention, the feather, for at least one bat?” (297) He discounts the possibility of common design plans or themes.
When it comes to design, the author has very strong feelings and does not hesitate to vent his frustrations. Throughout the book, and especially in chapter eleven, History Written All Over Us, Dawkins points out some of the examples of poor “design” he sees in nature. He finds the eye particularly appalling. “Once again, send it back, it’s not just bad design, it’s the design of a complete idiot.” (354) It is “obvious stupidity” that the retina is back to front. (356)
Luckily, evolution has fixed the errors and aberrations of the poorly designed eye by compensating: “…the brain does an amazing job of cleaning the images up afterwards, like a sort of ultra-sophisticated, automatic Photoshop.” He continues, “what they eye lacks in optics the brain makes up for with its sophisticated image-simulating software.” (353) Natural selection fixed it:
…the eye would be terrible at seeing, and it is not. It is actually very good. It is good because natural selection, working as a sweeper-up of countless little details, came along after the big original error of installing the retina backwards, and restored it to a high-quality precision instrument. (355)
Yes, Dawkins will admit it looks designed: “When we look at animals from the outside, we are overwhelmingly impressed by the elegant illusion of design.” (370) But all appearance of design must be ejected in light of the fact of evolution: “… the illusion of design makes so much intuitive sense that it becomes a positive effort to put critical thinking into gear and overcome the seductions of naïve intuition.” (371)
As Dawkins explains later in the book, this mere appearance of design fooled even the greatest minds:
…energy from the sun powers life, to coax and stretch the laws of physics and chemistry to evolve prodigious feats of complexity, diversity, beauty, and an uncanny illusion of statistical improbability and deliberate design. So compelling is that illusion that it fooled our greatest minds for centuries, until Charles Darwin burst onto the scene. (416)
Dawkins has an answer to this apparent design. Simply look on the inside of the animal to see just how haphazard it really is:
the overwhelming impression you get from surveying any part of the innards of a large animal is that it is a mess! Not only would a designer never have made a mistake like that nervous detour; a decent designer would never have perpetuated anything of the shambles that is the criss-crossing maze of arteries, veins, intestines, wads of fat and muscle, mesenteries and more. (371)
Apparently, real design would look more like a car exhaust, as Dawkins points out:
I think it would be an instructive exercise to ask an engineer to draw an improved version of, say, the arteries leaving the heart. I imagine the result would be something like the exhaust manifold of a car, with a neat line of pipes coming off in orderly array, instead of the haphazard mess that we actually see when we open a real chest. (371)
Dawkins’ “designer” doesn’t live up to his standard of completely optimal design. For evolution, however, Dawkins doesn’t require perfection. This is because he understands that optimal design is a delicate balance of trade-offs; a give and take of one benefit to the loss of another:
It is the lesson of trade-offs, and we have already adverted to it when talking about pollination strategies in plants. Nothing is free, everything comes with a price tag. (69)
The lesson applies to all living creatures. We can expect bodies to be well equipped to survive, but this does not mean they should be perfect with respect to any one dimension. (70)
This is just one hypothetical example of the many hundreds of trade-offs and compromises that all animals and plants juggle. They juggle with risks and they juggle with economic trade-offs. […] As you would expect, the optimum compromise in a trade-off is not fixed. (385-386)
In any flying machine, there is a trade-off between stability and maneuverability. (348)
Dawkins stresses that the poor “designs” we see in living things make perfect sense if we forget design. He explains as much when expounding on the poor design of the laryngeal nerve: “it makes perfect sense the moment you forget design and think history instead. To understand it, we need to go back in time to when our ancestors were fish.” (356)
Looking to history explains many things, including goosebumps:
…you get goosebumps. Why? Because your ancestors were normal mammals with hairs all over, and these were raised or lowered at the behest of sensitive body thermostats. […] In later evolution, the hair-erection system was hijacked for social communication purposes. (339-340)
Chapter twelve is entitled Arms Races and ‘Evolutionary Theodicy.’ Previously, Dawkins’ goal was to show that poor design proved that individual creatures were not designed. Now, his goal is to show that nature as a whole was not well designed, yet it makes perfect sense in light of Darwinism. A central planner would not have allowed inefficiencies, imperfections, or pain. Enter evolution:
Evolutionary biologists see no problem, because evil and suffering don’t count for anything, one way or the other, in the calculus of gene survival. Nevertheless, we do need to consider the problem of pain. Where, on the evolutionary view, does it come from? Pain, like everything else in life, we presume, is a Darwinian device, which functions to improve the sufferer’s survival. (393)
Chapter thirteen, There is Grandeur in this View of Life, is Dawkins’ final chapter. His view of life compels a sort of noble reflection: “Yes, there is grandeur in this view of life, and even a kind of grandeur in nature’s serene indifference to the suffering that inexorably follows in the wake of its guiding principle, survival of the fittest.” (401)
Included in this chapter are Dawkins’ expositions on the role that DNA plays in the evolutionary process. “No matter how elaborate and different the high-level programs that underlie the various life forms, all are, at bottom, written in the same machine language.” (410) Having previously contended that DNA should not be viewed as a blueprint or a plan, he settles on using the word “recipe” instead:
In the case of DNA, we understand pretty well how the information content builds up over geological time. […] Because there are occasional errors in the copying, new variants may survive even better than their predecessors, so the database of information encoding recipes for survival will improve as time goes by. (405)
As these copying errors occur, building a better and better recipe over geological time, they also somehow retain the helpful living habits and instincts of their particular species. As Dawkins explains:
The DNA in predator gene pools will increasingly contain information about prey animals, their evasive tricks and how to outsmart them. The DNA in prey gene pools will come to contain information about predators and how to dodge and outrun them. The DNA in all gene pools contains information about parasites and how to resist their pernicious invasions. (406)
But where does this DNA information originate? Dawkins doesn’t explore that issue; he dismisses it: “We don’t actually need a plausible theory of the origin of life…” (421) But he does offer his own brief accounting of origins:
We know a great deal about how evolution has worked ever since it got started, much more than Darwin knew. But we know little more than Darwin did about how it got started in the first place. This is a book about evidence, and we have no evidence bearing upon the momentous event that was the start of evolution on this planet. (416)
We have no evidence about what the first step in making life was, but we do know the kind of step it must have been. It must have been whatever it took to get natural selection started. […] And that means the key step was the arising, by some process as yet unknown, of a self-replicating entity. Self-replication spawns a population of entities, which compete with each other to be replicated. (419)
Dawkins ends his book on a note of eloquence: “We are surrounded by endless forms, most beautiful and most wonderful, and it is no accident, but the direct consequence of evolution by non-random natural selection – the only game in town, the greatest show on earth.” (426) The appendix offers a less eloquent reprise, as he offers his final lament against the “history-deniers.”
The Greatest Show on Earth is a well-written book. It is enjoyable on multiple levels. To be sure, the great majority of the content is completely unobjectionable to those who would doubt Darwinism as a comprehensive history of the development of life. Frankly, Dawkins presents the facts of microevolution very well.
But does Dawkins accomplish his overall thesis to demonstrate macroevolution as a fact? This reviewer found Dawkins’ thesis to fall short on three points: His case was incomplete, inconsistent, and ultimately insufficient to reach the doubter. Each of these can be unpacked briefly.
The case was incomplete: The doubter will not be persuaded when Dawkins excludes certain conclusions and certain lines of evidence from his investigation before he begins. Throughout, Dawkins has said: “I have used the metaphor of a detective, coming on the scene of a crime after it is all over and reconstructing from the surviving clues what must have happened.” (111) If this is case, then it seems the detective has limited his pool of suspects to natural causes, he has limited his evidence to only those clues that point to his preferred suspect, and he has not interacted with evidence outside of one field. Dawkins spent his energy on creationist parodies and ignored the leading proponents of intelligent design.
The case was inconsistent: The doubter will not be persuaded with the inconsistent treatment of apparent design. When something functioned well, evolution was credited. If something functioned poorly (in his estimation), design was discredited. In addition, Dawkins used the word evolution so loosely and inconsistently that the doubter would be hard-pressed not to find him guilty of equivocation on multiple counts. This did not help his case, as one may fully agree with evolution on a certain scale, but only to an observable point. In the eyes of the doubter, Dawkins makes the word evolution mean anything: it can mean change, it can be a force, it can be clever, etc.
The case was insufficient: Dawkins made grandiose claims in his first chapters. He set the bar very high. This is like introducing a joke by saying, “this is going to be the funniest joke you’ve ever heard…” What follows is sure to disappoint. But the real insufficiency in Dawkins’ case, in this reviewer’s estimation, was Dawkins’ amazing logical jumps and marshalling of ambiguous data. The author’s many unwarranted extrapolations and fallacies of affirming the consequent are simply not excusable for an Oxford professor. This is insufficient to bridge the logical gap between microevolutionary facts and macroevolutionary extrapolations.
In conclusion, The Greatest Show on Earth will educate and elucidate the reader who is ignorant of the Dawkins’ views of evolution. The book will give the careful reader plenty of raw data to make his own inferences to the best explanation. Unfortunately, Dawkins’ combative, condescending rhetoric may not impress the “history-deniers” he hopes to persuade. In sum, Richard Dawkins’ has written an enjoyable and informative book that promises much, but does not fully deliver on its promises.
Citations from Richard Dawkins, The Greatest Show on Earth: The Evidence for EvolutionLondon, England: Bantam Press, 2009).