Richard Dawkins’ The Greatest Show on Earth hopes to convey and document some of the evidence which compels him to embrace a Darwinian perspective on origins. Dawkins is also author of The God Delusion and probably today’s best known Darwinian apologist. Dawkins, in his 2009 book, The Greatest Show on Earth, lives up to his legendary reputation of creative tale-telling.
Just how strong are Richard Dawkins’ arguments? Does he present anything new? Do his claims stand up when subjected to careful scrutiny? Richard Dawkins clearly thinks so. In chapter 1 of his book, entitled Only a theory? Dawkins remarks:
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 eye witnesses to the Holocaust. It is the plain truth that we are cousins of chimpanzees, somewhat more distant cousins of monkeys, more distant cousins still of aardvarks and manatees, yet more distant cousins of bananas and turnips…continue the list as long as desired. That didn’t have to be true. It is not self-evidently, tautologically, obviously true, and there was a time when most people, even educated people, thought it wasn’t. It didn’t have to be true, but it is. We know this because 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.
One wonders, of course, how many times Richard Dawkins believes that he has to rephrase the core contention of his book in order to legitimise it!
Richard Dawkins further remarks:
…Imagine you are a teacher of recent history, and your lessons on 20th century Europe are boycotted…by politically muscular groups of Holocaust deniers. The plight of many science teachers today is not less dire. When they attempt to expound the central principle of biology they are harried and stymied, hassled and bullied.
Such dogmatic rhetoric and ad-hominen name-calling is highly indicative of the level of Dawkins’ argumentation. Nonetheless, it should be noted that no critic of Darwinism seeks the outlawing of the concept of evolution — or even common descent — from the academic environment. Rather, most critics would argue that the significant criticisms of Darwinism — which are, as yet, without resolution — should be referenced such that Darwinism is not taught in an uncritical fashion. Richard Dawkins’ claim, then, that critics want to torpedo the public education system is a simple point of misrepresentation.
The Origin of Life
Richard Dawkins, in The Greatest Show on Earth, has very little to say concerning the most fundamental challenge to standard materialistic thinking, namely the problem of life’s origin. In chapter 13 of his book, Dawkins writes:
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. Before that first step, the sorts of improvement that only natural selection can achieve were impossible. And that means the key step was the rising, by some process as yet unknown, of a self-replicating entity.
Dawkins is overlooking or ignoring a host of key points here. As Dawkins himself concedes, natural selection can only occur in organisms which are capable of reproducing or replicating themselves. But surely any self-replicating mechanism must exhibit a definable minimal level of complexity, let alone the necessitude of functional, and thus sequence specific DNA and protein molecules. As theoretical biologist Howard Pattee explains in his The Problem of Biological Hierarchy: “There is no evidence that hereditary evolution occurs except in cells which already have…the DNA, the replicating and translating enzymes, and all the control systems and structures necessary to reproduce themselves.” In order to invoke a materialistic pathway which can account for the origin of specified information in DNA, the naturalist must invoke a process that itself depends upon pre-existing sequence specific DNA molecules. Yet, the origin of these molecules is precisely what the thesis seeks to explain. And let us not forget that it is not merely the sequence of base-pairs comprising the information in DNA which is the chief concern at this point — but the problem becomes even deeper when confronted with the paradox of the origin of the genetic code itself. For further discussion of the origin of life and the genetic code, please see my articles here and here.
The RNA World
Dawkins’ The Greatest Show on Earth, proceeds to outline the classic Catch-22 paradox which concerns the relationship of DNA to proteins. He writes:
The ‘Catch-22’ of the origin of life is this. DNA can replicate, but it needs enzymes in order to catalyse the process. Proteins can catalyse DNA formation, but they need DNA to specify the correct sequence of amino acids. How could the molecules of the Early Earth break out of this bind and allow natural selection to get started?
How does Dawkins attempt to resolve this enigma? He continues:
Now for the key point of the ‘RNA World theory’ of the origin of life. In addition to stretching out in a form suitable for passing on sequence information, RNA is also capable of self-assembling…into three-dimensional shapes which have enzymatic activity. RNA enzymes do exist. They are not as efficient as protein enzymes, but they do work. The RNA World theory suggests that RNA was good enough enzyme to hold the fort until proteins evolved to take over the enzyme role, and that RNA was also a good enough replicator to muddle along in that role until DNA evolved.
Curiously, Richard Dawkins spends no time in The Greatest Show on Earth attempting to address the numerous criticisms of the RNA-first model. For example, the formation of the first RNA molecule would have necessitated the prior emergence of smaller constituent molecules, including ribose sugar, phosphate molecules and the four RNA nucleotide bases. But both synthesising and maintaining these essential RNA molecules (particularly ribose) and the nucleotide bases is profoundly problematic to perform under realistic prebiotic conditions.
Further, naturally occurring RNA molecules possess very few of the specific enzymatic properties of proteins. Ribozymes can perform a small handful of the thousands of functions performed by proteins. The inability of RNA molecules to perform many of the functions of protein enzymes raises a third and related concern with regard to the tenability of the RNA-first model. To date, no plausible explanation has been advanced as to how primitive self-replicating RNA molecules could have made the transition into modern cellular systems which depend heavily on a variety of proteins to process genetic information. Consider the transition from a primitive replicator to a system for building the first proteins. Even if such a system of ribozymes for building proteins had arisen from an RNA replicator, that system of molecules would still require information-rich templates for building specific proteins. To date, there is no materialistic pathway by which specified information can be readily produced. For further discussion of the RNA world, please see my articles here and here.
The Cambrian Explosion
To Dawkins’ credit in The Greatest Show on Earth, he does provide a reasonably detailed commentary on the geological incident known as the “Cambrian Explosion” (a phenomenon which is curiously omitted in many popular Darwinian texts) in his chapter on “The Missing Link? – What do you mean, ‘missing’?”. Richard Dawkins makes reference to the famous flatworms known as the Platyhelminthes:
This great phylum of worms includes the parasitic flukes and tapeworms, which are of great medical importance. My favourites, however, are the free-living tubellarian worms, of which there are more than four thousand species; that’s about as numerous as all the mammal species put together…They are common, both in water and on land, and presumably have been common for a very long time. You’d expect, therefore, to see a rich fossil history. Unfortunately, there is almost nothing. Apart from a handful of ambiguous trace fossils, not a single fossil flatworm has ever been found. The Platyhelminthes, to a worm, are ‘already in an advanced state of evolution, the very first time they appear. It is as though they were just planted there, without any evolutionary history.’ But in this case, ‘the very first time they appear’ is not the Cambrian but today. Do you see what this means, or at least ought to mean for creationists? Creationists believe that flatworms were created in the same week as all other creatures. They have therefore had exactly the same time in which to fossilise as all other animals. During all the centuries when all those bony or shelly animals were depositing happily alongside them, but without leaving any significant trace of their presence in the rocks. What, then, is so special about gaps in the record of these animals that do fossilise, given that the past history of the flatworms amounts to one big gap: even though the flatworms, by the creationists’ own account, have been living for the same length of time? If the gap before the Cambrian Explosion is used as evidence that most animals suddenly sprang into existence in the Cambrian, exactly the same ‘logic’ should be used to prove that the flatworms sprang into existence yesterday. Yet this contradicts the creationist’s belief that flatworms were created during the same creative week as everything else. You cannot have it both ways. This argument, at a stroke, completely destroys the creationist case that the Precambrian gap in the fossil record weakens the evidence for evolution.
Again, Richard Dawkins is missing the point with regards to the fossil record. Before examining the underlying fallacy of Dawkins’ argument, let us take a moment to consider the theological undertones in the above text. Theological arguments — by their very nature — cannot be defended as a scientific statement, and thus ought to be given no place in scientific discussions regarding evolution. The subtitle of Dawkins’ book is The Evidence for Evolution. There should be no need, therefore, to prop up Darwinism by appealing to theologically-related considerations. The age of the earth and the proper interpretation of Genesis is the subject of heated debate among Christians. While I do believe that this is a very interesting and important issue (I personally strongly favour the view that the earth is very ancient), it should not be featuring in scientific discourses concerning the scientific evidence relating to evolution. Moreover, to categorically place all Darwin-skeptics in the same category is misleading.
Leaving that point aside, let us turn to Richard Dawkins’ understanding of the Cambrian explosion. First, even if we were to grant him his premise — namely, the contention that organisms prior to the Cambrian were of a non-fossilisable composition (which is plausible) — this is not the point in question. Indeed, it is to be expected that non-skeletonized predecessors ought to leave few if any fossils. If it were the case, therefore, that one evolving line appeared suddenly in the fossil record, once it reached the stage of being fossilizable, then Dawkins might have a point here. But the real challenge of the Cambrian explosion is the wide variety of fossilizable forms which appeared at more or less the same instant in geological time. Every single phyla represented by modern day organisms — certainly all those with fossilizable parts — were included, yet for none is there any clearly identifiable ancestor. It is explaining the simultaneous and abrupt appearance of those which is one of the leading challenges in evolutionary biology.
Dawkins’ argument here is by no means original. Interestingly, over the last century and a half since the publication of Darwin’s Origin of Species, paleontologists have discovered many Precambrian fossils, many of them microscopic or soft-bodied. As Darwinian paleobiologist William Schopf wrote in his The early evolution of life: solution to Darwin’s dilemma, “The long-held notion that Precambrian organisms must have been too small or too delicate to have been preserved in geological materials…[is] now recognised as incorrect.” If anything, the abrupt appearance of the major animal phyla, conventionally dated to about 540 million years ago, is better documented now that in Darwin’s time. Indeed, as more fossils are discovered it becomes clear that the Cambrian explosion was even more abrupt and extensive than previously envisioned.
At any rate, as discussed in some detail here, the Ediacaran fauna are not generally thought to be ancestral to the modern phyla which appear explosively in the Cambrian radiation. The presence of these organisms, therefore, should offer no comfort to Darwinists. As Peter Ward has observed in On Methuselah’s Trail: Living Fossils and the Great Extinctions, “[L]ater study cast doubt on the affinity between these ancient remains preserved in sandstones and living creatures of today; the great German paleontologist A. Seilacher, of Tübingen University, has even gone so far as to suggest that the Ediacaran fauna has no relationship whatsoever with any currently living creatures. In this view, the Ediacaran fauna was completely annihilated before the start of the Cambrian fauna.” (p. 36)
Moreover, many phyla (such as the brachiopods and arthropods) couldn’t have evolved their soft parts first and then added the hard parts (such as the exoskeleton or shell) later — their survival depends in large measure upon the ability to protect or shield their soft parts. Soft and hard parts had to arise together. Finally, the critic of Darwinism need not point to the fossil record as the most compelling decisive blow to Darwinian orthodoxy. Dawkins is free to invoke ad-hoc hypothesis in an attempt to explain away the gaps and challenges presented by the fossil record at the most crucial points. Nonetheless, the fact remains that the fossil record simply cannot be used to document anything relating to the common descent of all life forms — which is one of the two central claims of neo-Darwinism. To state otherwise is to engage in circular reasoning.
Exaggerations and Over-Statements
Richard Dawkins’ The Greatest Show on Earth, explains in great detail how evolution has occurred “before our very eyes”. He makes reference to the replication of the well-known bacterium E. coli as a means by which we can simulate ‘deep time’. He notes that while lizards experience a generation turnover period of about two years, bacterial generations are measured in hours, or even minutes. He points to Michigan professor Richard Lenski’s experiment where 12 identical lines of E. coli were cultured to over 44,000 generations (20 years later). The bacteria were grown in a medium which had a small amount of glucose (a primary carbon source for E. coli) and abundant citrate (a carbon source not normally utilised by E. coli). Every 500 generations, Lenski would take samples of the bacteria, which — as Dawkins puts it — in essence produced a ‘fossil record’ of the different tribes. Lenski observed many changes in the E. coli as they adapt to the culture conditions in his lab. While the fitness of bacteria had increased, it had come at a cost. For instance, all the tribes had lost the ability to catabolise ribose. Some tribes had lost the ability to repair DNA. These bacteria may indeed be more fit in a lab setting, but when placed back into their environment alongside their wild-type counterparts, they would be at a selective disadvantage.
Dawkins goes on to explain that at generation 31,500, one line of E. coli was found to be able to utilise citrate. What Dawkins does not give us, however, is a rebuttal to the numerous pertinent comments which have been given by ID proponents with regards to Lenski’s work. Michael Behe, for example, discusses Lenski’s work on pages 140-142 of his book, The Edge of Evolution, and — more recently — in a peer-reviewed article in the Quarterly Review of Biology. Behe has also been keeping tabs on Lenski’s work over on his Uncommon Descent blog. Please also see Casey Luskin’s excellent recent blog entry on this topic on Evolution News & Views.
The case of the citrate transporter seems, to me, to be a weak one because it has been documented that wild-type E. coli can already use citrate under low-oxygen conditions. Under these conditions, citrate is transported into the cell (Pos et al. 1998). The gene in E. coli specifies a citrate transporter. In the presence of high levels of oxygen, it is thought that the citrate transporter doesn’t function or is not produced. Thus, wild-type E. coli already possesses the genes necessary for the transportation of citrate into the cell and its subsequent utilisation. Indeed, Lenski et al. (2008) note that “A more likely possibility, in our view, is that an existing transporter has been co-opted for citrate transport under oxic [high oxygen level] conditions.” Such a scenario could take place by a loss of gene regulation (meaning that the gene is no longer expressed exclusively under low oxygen conditions) or a loss of transporter specificity.
Do Dawkins’ Claims Regarding the Fossil Record Follow Logically?
In The Greatest Show on Earth, Dawkins spends considerable portions of his book expounding the fossil record. For example, in chapter 6 concerning the so-called missing links in the fossil record, he writes,
Creationists are deeply enamored of the fossil record, because they have been taught (by each other) to repeat, over and over, the mantra that it is full of “gaps”: “Show me your ‘intermediates!'” They fondly (very fondly) imagine that these “gaps” are an embarrassment to evolutionists. Actually, we are lucky to have any fossils at all, let alone the massive numbers that we now do have to document evolutionary history—large numbers of which, by any standards, constitute beautiful “intermediates.” We don’t need fossils in order to demonstrate that evolution is a fact. The evidence for evolution would be entirely secure even if not a single corpse had ever fossilized. It is a bonus that we do actually have rich seams of fossils to mine, and more are discovered every day. The fossil evidence for evolution in many major animal groups is wonderfully strong. Nevertheless there are, of course, gaps, and creationists love them obsessively.
Richard Dawkins — as a neo-Darwinist — is evidently seeking to demonstrate, and thus uphold, the central tenets of Darwinism. But the central claim of neo-Darwinism is that natural selection, coupled with chance mutation, can mimic what would normally be ascribed to intelligence. The most important issue which we have at hand, therefore, is whether or not life could have evolved by natural processes. The theory of intelligent design merely claims that certain natural phenomena exhibit features which are best attributed to intelligence. The concept of common descent is crucial to the Darwinian paradigm, but its falsehood is by no means critical to the design thesis. To the design hypothesis, as a scientific model, it is a secondary issue whether the various forms of life were created independently or by modification of previously existing forms. While the latter model rejects the theory of evolution as an overall paradigm, it is nonetheless consistent with common descent. Thus, even if one were to concede that the fossil record supports common descent — a notion which I challenge — it would not by any means prove neo-Darwinism.
What About the Missing Link?
Richard Dawkins defines the concept of “the missing link” as “the alleged gap between humans and the rest of the animal kingdom.” He spends much of the rest of his chapter on the fossil record taking on some of the pseudoscientific claims made by some in the name of creationism, for instance, the weak (to put it mildly) argument, ‘I’ll believe in evolution when I see a monkey give birth to a human baby.’ There are plenty of well-meaning creationists out there who utilise this level of argumentation — but to suggest or imply that such reasoning is ‘mainstream’ is very misleading indeed. There are many sophisticated and well-informed critiques of Darwinian orthodoxy in the scientific literature. Richard Dawkins should be responding to them, rather than the under-informed laypeople, who, perhaps should be spending less time teaching apologetics, more time getting their facts straight! (For the record, Darwinists do not believe that humans are descended from modern monkeys, but that modern monkeys and humans shared a common ancestor.).
In the proceeding chapter (chapter 7), Richard Dawkins outlines several fossil organisms which he deems to be feasible intermediates between humans and the common ancestor we share with chimpanzees. One example to which Dawkins alludes is ‘Lucy’. Dawkins remarks,
The most famous fossil…is ‘Lucy’, classified by her discoverer in Ethiopia, Donald Johanson, as Australopithecus afarensis. Unfortunately we have only fragments of Lucy’s cranium, but her lower jaw is unusually well preserved. She was small by modern standards, although not as small as Homo floresiensis, the tiny creature the newspapers have irritatingly dubbed ‘the Hobbit’, which died out tantalisingly recently on the island of Flores in Indonesia. Lucy’s skeleton is complete enough to suggest that she walked upright on the ground, but probably also sought refuge in trees, where she was an agile climber. There is good evidence that the bones attributed to Lucy really did all come from a single individual…The conclusion from studies of Lucy and her kin is that they had brains about the same size as chimpanzees’ but, unlike chimpanzees, they walked upright on their hind legs…
Indeed, Lucy’s skeleton is very incomplete. Only 40% was found, and a significant percentage of the known bones are rib fragments. As Dawkins notes, very little useful material from the skull was recovered. Ironically, Lucy still represents the most complete pre-Homo known hominid skeleton to date. Dawkins’ assertion that “There is good evidence that the bones attributed to Lucy really did all come from a single individual” is highly precarious. Given the fragmentary nature of many of the bones and the highly incomplete nature of the skeleton, the argument seems highly suspect. Consider, for example, Lucy’s femur or the pelvis, the most prized parts of her skeleton. It is an extremely difficult case to state that all Lucy’s bones are clearly from one individual of one species, and it requires some heavy assumptions.
Leaving the fragmentary nature of Lucy’s skeleton aside, let us assume for the moment that Lucy was a fully bipedal ape – would that necessarily qualify her as a human ancestor? Given that the much earlier fossil record from the Miocene yields bipedal apes that supposedly evolved upright-walking completely independently from the line that supposedly led to humans, it would seem that the answer is emphatically no.
Even if we concede that Lucy walked upright, there is strong evidence to suggest that her mode of locomotion was, in significant ways, very different from that of modern humans. For example, it is almost certain that A. afarensis and other australopithecines were not adapted to a striding gait and running, as humans are. It doesn’t seem very advantageous, and therefore likely, to use bipedality as one’s primary mode of locomotion if one cannot use it to quickly run from predators.
As Richard Leakey and Roger Lewin write in their book, Origins Reconsidered – In Search of What Makes us Human:
“We were sent a cast of the Lucy skeleton, and I was asked to assemble it for display,” remembers Peter Schmid, a paleontologist at the Anthropological Institute in Zurich. … “When I started to put [Lucy’s] skeleton together, I expected it to look human,” Schmid continues. “Everyone had talked about Lucy as being very modern, very human, so I was surprised by what I saw.” … “What you see in Australopithecus is not what you’d want in an efficient bipedal running animal,” says Peter. “The shoulders were high, and, combined with the funnel-shaped chest, would have made arm swinging very improbable in the human sense. It wouldn’t have been able to lift its thorax for the kind of deep breathing that we do when we run. The abdomen was potbellied, and there was no waste, so that would have restricted the flexibility that’s essential to human running.”
Richard Dawkins’ contention, then, that “[Lucy] walked upright on [her] hind legs, as we do…” ignores large volumes of skeletal evidence that Lucy did not in fact walk upright. The only real reason to discard Lucy’s clear anatomical evidence that she climbed trees and knuckle-walked is the Darwinist preference for her to be a fully-bipedal ape that was on her way toward evolving into a modern human. But this is circular.
What About Bad Design?
In chapter 11 of The Greatest Show on Earth, Richard Dawkins alludes to a number of systems which he regards to be badly or ‘unintelligently’ designed. The point he makes is a rather elementary logical fallacy — design does not have to be perfect; it just has to be good enough. The fact remains that living systems exhibit clear marks of the action of an intelligent agent, even if the design is somewhat less than perfect. As an analogy, consider Microsoft office software. Microsoft office applications often possess certain imperfections, but no-body would infer that the programming script was the product of undirected mechanisms. Ultimately, Richard Dawkins is here depending upon the utilisation of theological arguments in order to support his case. The theory of intelligent design states that certain features of the natural world exhibit indicators of intelligent design. Questions relating to the identity or skill of the designer are questions for theologians and philosophers to address, and thus stand independently from biological or scientific concerns.
Nonetheless, let us take one of Richard Dawkins’ examples of bad design, as presented in The Greatest Show on Earth, subject it to scrutiny and see how it holds up. If it can be demonstrated that there exists functional reasons for the relevant instances of apparent ‘bad design’ or if new evidence suggests a pattern of degenerative evolution (that is to say, evidence of decay of an otherwise rational and beneficial original design), then the argument would no longer hold water.
On page 353-355 of The Greatest Show on Earth, Richard Dawkins alludes to the often-cited example of the inversion of the vertebrate eye retina as an instance of ‘bad design’. However, recently identified functional reasons for this design challenge the old Darwinian claim. Biologist George Ayoub has shown, for example, that the vertebrate retina provides an excellent example of what engineers call a constrained optimisation, in which several competing design objectives are elegantly balanced to achieve an optimal overall design.
Light at various wavelengths is capable of inducing degenerative effects on biological machinery. The retina is clearly designed with the inbuilt purpose of withstanding the toxic and heating effects of light. The eye is well equipped to protect the retina against radiation from the outside world. Besides the almost complete exclusion of ultraviolate radiation by the cornea and the lens together, the retina also serves a crucial role in protection against such damage — for example, producing substances with combat the damaging chemical by-products of light radiation.
The photoreceptors, therefore, need to be in direct contact with the retinal pigment epithelium, which plays an essential part in sustaining them. The retinal pigment epithelium, in turn, requires to be in direct contact with the choroids. Both of these are required in order to satisfy the nutritional requirements and thus prevent overheating the retina from focused light (as a consequence of the heat sink effect of bloodflow).
If, conversely, the human retina were ‘wired’ the other way as Dawkins proposes that it should be, these two opaque layers would need to be interposed in the path of light to the photoreceptors , which really would be bad design!
Conclusion: Does Richard Dawkins have the goods?
Richard Dawkins continues in the same vein throughout his book. One favourable review of Dawkins’ book, published in The Guardian, commented that while The Greatest Show on Earth “demonstrates once again [Dawkins’] consummate skill as an explainer,” the science covered by the book mostly rehashed “pretty standard stuff.” The book fails to address the growing problems of biological information, the origin of life, how natural selection coupled with chance mutations can account for the origin of irreducibly complex systems, which continue to defy the Darwinism he preaches. Darwin called The Origin of Species ‘one long argument’ for his theory, but Richard Dawkins has given us one long bluff. The Greatest Show on Earth seeks to defend neo-Darwinism by appealing to theological arguments, by attempting to explain away the challenge of the Cambrian explosion by means of invoking ad-hoc conjectures, by exaggerating the evidence for the potentiality of natural selection, by misrepresenting design arguments, casting down ‘straw-men’, and by avoiding mention of the most sinister threats to the neo-Darwinian model of origins.
Another point which is worth mentioning is that one should not be so taken with the evidence that is consistent with evolution that we think we can ignore the evidence that contradicts it. And this isn’t a balancing act — weighing whether there is more evidence for or against the theory. We know from common experience that even a small amount of clearly contradictory evidence outweighs a large body of consistent evidence. A common thread running throughout Richard Dawkins’ book (The Greatest Show on Earth) is the analogy of weighing up incriminating evidence in a court of law. But in a court of law, no matter how much evidence appears to incriminate someone, it would be entirely outweighed by a reliable alibi that the accused was in a totally different location at the time of the crime. The same is true of science. Even a small amount of attestable data that clearly contradicts evolution is sufficient to demonstrate that it is false, despite a much larger body of evidence that is consistent with it.
The actual evidence shows that major features of the fossil record and cell biology are an embarrassment to Darwinian evolution. Judged by the normal criteria of empirical science, the data used to prop up neo-Darwinism is weak. We know today that there are multiple critical facts which strike hard blows at the conventional understanding of the theory. These are not merely trivial problems or anomalies that are likely to be solved, but fundamental matters that appear to be without prospect of solution.