The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe without Design is a 1986 book byRichard Dawkins, in which he presents an explanation of, and argument for, the theory ofevolution by means ofnatural selection. He also presents arguments to refute certain criticisms made of his first book,The Selfish Gene. (Both books espouse thegene-centered view of evolution.) It was illustrated by Liz Pyle. It won theLos Angeles Times Book Prize for Current interest.[1] A computer program of the same name was released[2] and it was the basis for aBBC documentary.[3] An audiobook was released, read by Dawkins andLalla Ward.
The title of the book refers to thewatchmaker analogy made famous byWilliam Paley in his 1802 bookNatural Theology or Evidences of the Existence and Attributes of the Deity.[4] Paley, writing long beforeCharles Darwin publishedOn the Origin of Species in 1859, held that the complexity of living organisms was evidence of the existence of adivine creator by drawing a parallel with the way in which the existence of a watch compels belief in an intelligent watchmaker. Dawkins, in contrasting the differences between human design and its potential for planning with the workings of natural selection, therefore dubbed evolutionary processes as analogous to a blind watchmaker.
"Biomorph" that randomly evolves following changes of several numeric "genes", determining its shape; the gene values are given as bars on the top
1. Explaining the Very Improbable
Dawkins addresses the argument from design. He emphasizes that natural selection is nonrandom (since only adaptive traits are selected for) and cumulative (as adaptive traits accumulate).
2. Good Design
Dawkins discusses the evolution of echolocation inbats. Many animals have some ability to navigate by sound. Such abilities can be honed by natural selection to produce the sophisticated sonar seen in bats.
3. Accumulating Small Change
Dawkins writes that "We have seen that living things are too improbable and too beautifully 'designed' to have come into existence by chance. How then, did they come into existence? The answer, Darwin's answer, is by gradual, step-by-step transformations from simple beginnings. ... Each successive change in the gradual evolutionary process was simple enough,relative to its predecessor, to have arisen by chance. But the whole sequence of cumulative steps constitutes anything but a chance process. ... The cumulative process is directed by non-random survival."[5]
Dawkins illustrates the difference between the potential for the development of complexity as a result of pure randomness, as opposed to that of randomness coupled with cumulative selection. He demonstrates this by the example of theweasel program. Dawkins then describes his experiences with a more sophisticatedcomputer simulation of artificial selection implemented in a program also calledThe Blind Watchmaker, which was sold separately as a teaching aid.
The program displayed a two-dimensional shape (a "biomorph") made up of straight black lines, the length, position, and angle of which were defined by a simple set of rules and instructions (analogous to a genome). Adding new lines (or removing them) based on these rules offered a discrete set of possible new shapes (mutations), which were displayed on screen so that the user could choose between them. The chosen mutation would then be the basis for another generation of biomorph mutants to be chosen from, and so on. Thus, the user, by selection, could steer the evolution of biomorphs. This process often produced images which were reminiscent of real organisms, for instancebeetles, bats, ortrees. Dawkins speculated that the unnatural selection role played by the user in this program could be replaced by a more natural agent if, for example, colourful biomorphs could be selected by butterflies or other insects, via a touch-sensitive display set up in a garden.
4: Making Tracks Through Animal Space
Dawkins looks at theevolution of the eye. Many animals have a patch of light-sensitive cells. Natural selection would favor the formation of a "cup" which can detect direction. From there you can get apinhole camera eye, as seen in thechambered nautilus. The addition of a lens results in thecephalopod eye. "For each of these types of eye, stages corresponding to evolutionary intermediates exist as working eyes among modern animals."[6] Any improvements would be favored by natural selection. In fact, eyes have evolved several times independently, an example ofconvergent evolution. He returns to echolocation, noting that "Any animal that can hear at all may hear echoes. Blind humans frequently learn to make use of these echoes. A rudimentary version of such a skill in ancestral mammals would have provide ample raw material for natural selection to build upon, leading by gradual degrees to the high perfection of bats."[7] Echolocation also seems to have evolved several times independently, another example of convergent evolution.
Dawkins looks at Darwin's concept ofsexual selection, revived by R. A. Fisher. It is thought that peacocks evolved colorful plumage to attract peahens. But the peahens are also passing along genes preferring plumage. This is an example oflinkage disequilibrium, which can lead to runaway evolution.
Dawkins examines alternatives to natural selection, likeLamarckism, and finds them wanting.
In an appendix to the 1996 edition, Dawkins explains how his experiences with computer models led him to a greater appreciation of the role ofembryological constraints on natural selection. In particular, he recognised that certain patterns of embryological development could lead to the success of a relatedgroup of species in filling varied ecological niches, though he emphasised that this should not be confused withgroup selection. He dubbed this insightthe evolution of evolvability.
Tim Radford, writing inThe Guardian, noted that despite Dawkins's "combative secular humanism", he had written "a patient, often beautiful book... that begins in a generous mood and sustains its generosity to the end." 30 years on, people still read the book, Radford argues, because it is "one of the best books ever to address, patiently and persuasively, the question that has baffled bishops and disconcerted dissenters alike: how did nature achieve its astonishing complexity and variety?"[4]
Philosopher and historian of biologyMichael T. Ghiselin, writing inThe New York Times, comments that Dawkins "succeeds admirably in showing how natural selection allows biologists to dispense with such notions as purpose and design". He notes that analogies with computer programs have their limitations, but are still useful. Ghiselin observes that Dawkins is "not content with rebutting creationists" but goes on to press home his arguments againstalternative theories to neo-Darwinism. He thinks the book fills the need to know more about evolution that creationists "would conceal from them." He concludes that "Readers who are not outraged will be delighted."[8]
Kenneth R. Miller writes that Dawkins "brilliantly explains how complex mechanisms and structures are put together by the process of evolution" adding "It is true that he makes certain theological points that I don’t agree with."[9]
Jerry Coyne also recommends the book: "I’ve always thought of Dawkins as an extremely smart child. He is not a child of course, he’s a really brilliant man. But he looks at things with the eyes of a child, in a way that I don’t think any scientist who wrote really well, including Stephen Jay Gould, ever could. He sees things with this fresh viewpoint that brings them alive."[10]
The American philosopher of religionDallas Willard, reflecting on the book, denies the connection of evolution to the validity of arguments from design to God: whereas, he asserts, Dawkins seems to consider the arguments to rest entirely on that basis. Willard argues that Chapter 6, "Origins and Miracles", attempts the "hard task" of making not just a blind watchmaker but "a blind watchmaker watchmaker", which he comments would have made an "honest" title for the book. He notes that Dawkins demolishes several "weak" arguments, such as the argument from personal incredulity. He denies that Dawkins's computer "exercises" and arguments from gradual change show that complex forms of life could have evolved. Willard concludes by arguing that in writing this book, Dawkins is not functioning as a scientist "in the line of Darwin", but as "just a naturalist metaphysician".[11]
The engineerTheo Jansen read the book in 1986 and became fascinated by evolution and natural selection. Since 1990 he has been buildingkinetic sculptures, theStrandbeest, capable of walking when impelled by the wind.[12]
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