I found a good review on Dawkins' "the blind watchmaker" it begs to be posted here:
http://www.geocities.com/a_and_e_uk/BlindWatch.htm
eview of Richard Dawkins, The Blind Watchmaker (London 1991)
ISBN: 0140144811
Debates about Darwinism rage as fiercely as they did when the Origin of Species was published in 1859. Opponents of Darwinism come from a variety of directions. Those with a religious background often argue using creationist arguments, whilst others provide alternative scientific theories such as mutationism. A third group, including punctuationists, argue for a modified Darwinian theory. The Blind Watchmaker is Dawkins’ attempt to prove all these people wrong whilst simultaneously educating the layman about what Darwinism actually is.
Dawkins writes in a clear and accessible way, instantly allaying any fears that the reader might have about being incapable of understanding the concepts of Darwinism. This is achieved by a copious use of analogies and real-world examples that are unfailingly fresh, exciting and informative. Not only does the reader get an education in Darwinism, but also in biology, taxonomy, linguistics, engineering and computing. The book’s structure also helps to make the concepts accessible. Each chapter is a self-contained topic that has little impact on the discussions in the following chapters. This ensures that the reader never feels that they are halfway through a chapter, but have forgotten a basic concept explained three chapters ago. Because of this structure, a summary of the book’s content will tend to be episodic in nature. On this matter I beg your indulgence.
The first chapter explains what Dawkins means by ‘complexity’. No doubt there will be some physicists who will feel slighted at Dawkins’ dismissal of their subject as simple, but they would be missing the point he is trying to make. For Dawkins, a complex object is one whose approximate form and (more importantly) function is unlikely to emerge if its constituent parts were thrown together at random. Examples of Dawkins’ definition of complexity are such things as complex machinery or biological entities, the function of the latter being to stay alive.
Having established this, Dawkins goes on to justify what he believes to be an appropriate degree of explanation. In this case, he judges this to be an explanation to the level where ‘entities are so simple that they can be safely handed over to the physicists’. Just to prove what a detailed level of explanation this is, he ends the chapter by describing the intricate structure of the eye.
Chapter 2 continues his exploration of the complexity of the biological world through a thrilling description of the echo-location system in bats. This takes up the majority of the chapter, leaving only a small space for what he really wants to attack: ‘the argument of Personal Incredulity’. This, reduced to its simplest form, equates to the oft-quoted Richard Wilson catchphrase, ‘I don’t believe it!’. To make this line of argument seem particularly foolish he uses a passage written by an unfortunately under-educated bishop, Hugh Montefiore, who could not think of a selection advantage for polar bears being white. There is a very obvious advantage to being white if you are a polar bear – your prey is less likely to see you as you stalk them. By pointing this out Dawkins makes Montefiore and all of Montefiore’s arguments seem unreasonable. The destruction of the reader’s disbelief at the immense probabilities involved in the workings of evolution is essential for making many of his proposition convincing. So essential, in fact, that he discusses probabilities again later on in the book.
In Chapter 3 Dawkins starts to describe the processes involved in evolution. He shows, with the aid of computer programs, how cumulative adaptation vastly increases the probability of a structure developing. This is convincingly demonstrated by a computer which takes an input phrase, ‘mutates’ it and then selects the best mutant progeny to ‘breed’ the next generation of mutant phrases from it. In this case ‘best’ is defined as closest to the target – METHINKS IT IS A WEASEL. Impressively, the computer progresses from WDLMNLTDTJBKWIRZREZLMQOCOP to the endpoint in a mere 43 generations. The probability of this phrase spontaneously arising by a single-step mutation is a staggering 1 in 1039.
The second half of the chapter refines the point by introducing a computer program which has no idealised endpoint. Through the alteration of a few basic variables, his second program produces drawings that look very similar to biological objects. This is all very interesting, but Dawkins takes a long time to get to the point of it all – that evolution by small gradual steps is far more likely than evolution by large jumps.
Using this thesis he then sets out to show that evolution of the eye is very simple to explain if you consider it in terms of small steps. ‘1% of vision is better then total blindness’ he notes. To further hammer the point home he takes a passage from Frank Hitching’s The Neck of a Giraffe: or Where Darwin Went Wrong, which claims that ‘the eye functions as a whole, or not at all’. Unfortunately for Hitching, not only are short-sighted people obviously better off than blind people, but there exists a squid-like creature called Nautilus, whose eyes do not have lenses. Dawkins is all too eager to point this out. Hitching’s book continues to provide Dawkins with opportunities to demonstrate his superior zoological knowledge, and Dawkins takes him to task with relish. In doing so, not only does he make Hitching look ridiculous but, by association, the idea that the eye could not have developed gradually is made to look ludicrous.
The last third of Chapter 4 continues Dawkins’ adventures in zoology, and uses copious examples to provide evidence of convergent evolution. Here Dawkins really shines, inspiring feelings of wonder and delight in the reader, whilst making the point that if specialised organs have evolved separately in two unrelated creatures then the process of evolution must be quite probable.
Chapter 5 begins by stating that the problem of blending has been solved by the discovery of Mendelian genetics. Since discrete genes are inherited, there can be only phenotypic blending, not genotypic blending. Having introduced the term gene, Dawkins takes the opportunity to digress into a long and fascinating discussion of the structure of DNA and the mechanism of its replication. Towards the end of this tangent he introduces evidence of spontaneously self-replicating RNA, an essential concept if you postulate that life originated in a puddle of primeval ooze.
Sure enough, Chapter 6 is devoted entirely to discussing the origin of life. Pride of place is given to the primeval puddle theory. God is sidelined as a facile argument within the first few pages of the chapter, leaving plenty of time to explain how evolution can provide an explanation of how life arose. Dawkins spends a lot of time looking at probability and, having, allocated the catchy moniker of Spontaneous Generation Probability (SGP) to the probability of life arsing spontaneously on Earth, he assigns it a value of 1 in one billion (on the basis of facts contained in chemistry textbooks). After playing with this figure for a few pages he concludes that life is so overwhelmingly probable that it is likely to have occurred ‘not just once but many times, all over the Universe’.
This established, he outlines Cairns-Smith’s theory of how clay replication could have led to the development of RNA, which in turn evolved into DNA and life as we know it. Just in case reader are beginning to find this a little improbable, he reiterates just how ridiculous it is to let mere implausibility get in the way of a good theory. After all, our brains are not built to accurately consider the range of probabilities needed.
Having now covered the really controversial subjects, Dawkins spend the next two chapters describing how evolutionary forces could foster further evolution and how sexual selection can lead to the emphasis of certain traits within a species. These two chapters are carefully and meticulously argued. Particularly effective is his demonstration of the power of sexual selection using the example of tails in African long-tailed widow birds.
In Chapter 8 Dawkins turns on saltationists and punctuationists, the opponents of the gradualist school of thought. Here again he is very convincing, showing that punctuationism and saltation, particularly saltation, are not plausible alternatives. In fact punctuationism is not an alternative to gradualism, but more of a slight re-wording of it (at least according to Dawkins). Amidst this discussion he briefly takes time out to explain speciation, another potential stumbling block to Darwinism, and accomplishes this in a mere two and a half pages. Perhaps as a result of his belief that the theory he describes is accepted by all orthodox neo-Darwinists as the main process by which species come into existence, Dawkins does not believe that it warrants more than a short explanation.
The rest of the book seems to be aimed more at his scientific colleagues than the layman. Chapter 10 discusses various systems of taxonomy and the superiority of schemes based on evolution over other schemes. Chapter 11 explains why alternative scientific theories to neo-Darwinism, such as Lamarckianism, mutationism, neutralism and molecular drive, are either completely ridiculous or not real opponents to neo-Darwinism. Just in case any readers were considering God again, he takes another opportunity to reduce God to the status of a silly argument. He concludes by stating that ‘natural selection is the ultimate explanation for our existence’. It now remains to discuss whether the arguments contained in The Blind Watchmaker are sufficiently strong to support such a sweeping statement.
Perhaps the main problem with many of Dawkins’ explanations is that he does not go into sufficient detail about the mechanisms of the processes he describes. Certainly, he rarely reaches the level of detail where entities are so simple that they can be handed over to the physicists. Having taken so much care to establish what a good level of explanation is in the first chapter, it seems odd (if not careless) that he should so often fall short of his own criterion.
A good example of this is his explanation of speciation. Earlier in the book Dawkins mentions that chimpanzees have 24 pairs of chromosomes whilst humans have 23. Therefore, we either lost a chromosome or the chimps gained one. The implication of this, he glibly remarks, is that ‘there must have been at least one individual who had a different number of chromosomes from his parents’. This does not seem to bother Dawkins, but the inquisitive reader is left wondering how this person bred with the rest of his or her population. Given that different species often have different numbers of chromosomes, this seems a particularly pertinent question in the case of speciation.
The subject of speciation is poorly dealt with in The Blind Watchmaker. Such a fundamental cornerstone of evolutionary theory deserves a lot more than two and a half pages. Having said that, there are subtle references to speciation in the chapter on taxonomy. At one point Dawkins say that the appearance of distinct species is merely an illusion, and in fact all species are a continuum. The reason that there appear to be separate species is that the intermediates have died out. This is all very well, but by the end of the book I do not feel that I have fully understood speciation. Of course, this may simply be because I am obtuse, but on the other hand a more detailed explanation would undoubtedly have helped.
In the same chapter that he discusses speciation, Dawkins discusses the origins of life. The Cairns-Smith theory is plausible enough while it suggests that RNA originally evolved as an aid to clay replication, and then the RNA self-replicated and evolved into DNA. However, when Dawkins suddenly makes the jump from DNA to life the plausibility ends. Can DNA self-replicate? He does not answer this question. Certainly in modern cells DNA replication is achieved with the help of multiple enzymes such as gyrases and polymerases. Are we supposed to believe that these evolved in the same zinc-filled puddle as the DNA? The DNA certainly could not code for them, because translation of DNA requires another whole set of enzymes. Even if all these proteins did develop beside the DNA and miraculously organised themselves into a simple cell (and many more proteins are required for this last step) it would be a staggering coincidence if the DNA, which had been randomly mutating while it ‘waited’ for the other cell elements to arise, should then code for the specific proteins required to replicate, transcribe and translate it into useful proteins. Dawkins’ only answer is, again, to warn against the lunacy of incredulity. It becomes apparent that the reason he has devoted as many paragraphs to ridiculing the incredulous is because he needs to make the reader feel incapable of questioning anything that seems unlikely. If the reader does take this (radical) step then many of Dawkins’ arguments become unconvincing.
Sometimes the tactic of mocking disbelieving opponents is used to ignore the question at the heart of the argument. When Hitching said that all the parts of the eye needed to be working together or the eye would not function at all, he certainly overstated the point. Dawkins has seized on this, and has showed how a partially sighted person is at a distinct advantage to a blind person. However, I believe that Hitching was trying to say that the structure of the smallest units of the eye is still very complex, and a great deal of complex structures need to be in place for even a rudimentary eye to work.
Take the most basic eye, a photoreceptor linked to some mechanism that produces a reflex response. Dawkins helpfully draws a diagram to display how complex a photoreceptor is, but for the purposes of our basic eye we will make the photoreceptor more simple and have it simply as a cell containing rhodopsin, the light sensitive protein in photoreceptors, linked to some simple hypothetical actuating mechanism, far simpler than the one in modern eyes that generates nervous impulses. If the structure of either rhodopsin or the actuating mechanism is imperfect then the cell will not be light-sensitive and the organism will have absolutely no survival advantage over its peers whatsoever. Hence, at the molecular level, Dawkins’ reductionist argument that 6% sight is better than 5.9% sight is better than 5.8% sight etc falls to pieces.
The development of enzymes is a very important topic. Dawkins attempts to show, with his METHINKS IT IS A WEASEL program, that cumulative adaptation is easily capable of explaining how proteins develop. However, in real life proteins that differ from the correct structure by even a single amino acid have a radically different conformation and are completely useless. Some of the body’s proteins are huge: haemoglobin, for example, is made up of two a globin chains and two b globin chains. The a chain is 141 amino acids long and the b chain is 146 amino acids long. This means that the a chain is coded for by a gene 423 base pairs long. There are many ‘critical sites’ along the chain where alteration of a single amino acid could result in the haemoglobin being completely non-functional. Thus, the alteration of a single base pair out of 423 could potentially lead to a protein that, despite being 99.764% correct, has no selection advantage whatsoever (and this is just if the a chain is miscoded). The b chain poses a similar problem. The only way that imperfect chains could be selected would be if the host organism simultaneously developed a different adaptation that gave it an advantage over its peers. This seems rather improbable, given that our bodies contain thousands of highly complex proteins. Was the evolution of each one really accompanied by the evolution of an advantageous adaptation?
Dawkins briefly mentions co-evolution when he describes how a certain genetic ‘climate’ favours the evolution of certain enzymes. To use his own example, if a biochemical pathway requires enzymes A1, B1 and C1, development of B1 is favoured if A1 and C1 are already present. The concept of A1 and C1 being produced by an organism for no reason (they cannot function effectively until B1 arrives) does not seem to bother Dawkins. His example is very simple, but most biochemical pathways consist of many enzymes. If you have a 20-enzyme pathway it seems unlikely that 19 of these enzymes will be propagated through a population until enzyme 20 develops, making the pathway useful. At some point one has to assess the probability of an event happening, and if that probability is vanishingly small then we can dismiss that event as effectively impossible. Physicists do this all the time to explain why a cow will not jump over the moon.
Making an assessment of such probabilities is very tricky, as Dawkins himself demonstrates while discussing the origins of life. His argument for the likelihood of life arising on Earth is dependant on the value he gives to the SGP. He guesses, and chooses what he regards as a small probability – 1 in one billion. To my mind this is a rather large probability, but that is not important. What is important is that Dawkins demonstrates absolutely no justification for choosing one in one billion as the value of the SGP. If his guess is wrong, then his argument is completely invalid. When you consider that this is meant to be the best evidence for the conclusion that life on Earth is a result of evolution, the theory looks ever more shaky.
In the same chapter Dawkins dismisses the idea of an eternal Creator as a ‘lazy way out’, because ‘to explain the origins of the DNA/protein machine by invoking a supernatural Designer is to explain precisely nothing, for it leaves unexplained the origins of the Designer’. However, if God really did create the universe then whether you can explain God or not changes nothing. We cannot fundamentally explain how gravity works – does this mean that it does not operate? Certainly not. Just because you cannot explain something does not mean that you should deny its existence. When trying to explain God, science is a completely inappropriate tool. No form of reasoning will prove His existence; you just have to take His omnipotence and eternal existence on faith. In much the same way, though science will ever be able to fully explain everything in the Universe we have to take its starting assumptions on faith if we are happy with the answers it provides.
At no stage does Dawkins admit this. He presents the theory of evolution as fact when it is merely one of many theories describing how life on Earth began. As demonstrated by Dawkins’ final chapter, neo-Darwinism is more plausible than many other scientific theories. However, scientific theories are not more inherently valid than religious ones. By failing to be open about this fact, by rushing over many of his calculations and by refusing to discuss critical details about the mechanism of evolution Dawkins loses much of the credibility that he might otherwise have kept. The reader is left wondering why Dawkins found it necessary to skim over so many details. Dawkins’ supporters might argue that they are sacrificed in terms of readability, and it is true that the book is refreshingly lucid and highly entertaining. However, at the end of the day readers have bought the book for a lesson in the mechanisms of evolution, not zoology. By failing to properly describe the mechanisms of evolution Dawkins not only fails to justify his conclusion but also renders his book the literary equivalent of a glass bauble – superficially attractive but ultimately worthless.
I'll get back to you on Lot's folly! ok!
Godless.
That I am. Here is what your probably don't understand: If the bible is the word of god, and it's writen on "his" manual Lot's action were, then JUSTIFIED in order to "PROTECT" god's agenls. OK!!