Pros: Scholarly and thorough presentation of evolution as the explanation for life
Cons: Dawkins confidence in his ideas has been described by some as arrogance
This is Dawkins second best-selling book on evolution, following his first, The Selfish Gene. The Blind Watchmaker was first published in 1986, and this review is based on a third edition published in 1997. There were no revisions from the original except a new Preface and an additional Appendix.
The title comes from the writing of William Paley in Natural Theology, published in 1802, in which he argued that the organization and complexity of living things prove the existence of a deity, the well-known Argument from Design. Dawkins shows great respect for Paley and his writing, saying his --argument is made with passionate sincerity, informed by the best biological scholarship of his day, but then goes on to say he was --wrong, gloriously and utterly wrong.
Dawkins builds his case for random mutation and natural selection as the blind watchmaker, starting with a discussion of what is meant by order and complexity, and an acknowledgement that living things are the most orderly and complex entities in existence, demanding an explanation of how such elegant and efficient organisms and apparent design came about. He says If anyone doesnt agree that this amount of complex design cries out for an explanation, I give up. No---I dont---because one of my aims---is to convey something of the sheer wonder of biological complexity---and to explain the solution to the mystery.
He succeeds on both counts, making a compelling case that neo-Darwinian natural selection is not only the correct explanation for the development of bio-diversity, but the only known possible explanation. The focus of the book is upon the statistical improbability of life on a colossal scale, and the astronomically long odds against the spontaneous arising of order and apparent design. The solution is to break this high improbability into many, many more probable small steps. The first step is the rise of simple molecules that have the ability to replicate themselves accurately, but with occasional errors. Dawkins provides a detailed description of one of several theories that could explain how this initial step might have occurred.
A replicating molecule leads in a few thousand steps to a bacteria-like single-celled life form, capable of replicating very accurately, but with an occasional error, or mutation. When a mutation arises that improves the ability to survive and reproduce, it is naturally selected, and quickly spreads throughout the whole population.
The mechanism of replication is carried out by genes, chromosomes, and DNA molecules, the means by which instructions for building protein molecules are preserved, replicated, and transmitted. All is carefully and clearly explained with many allegories and examples, in simple enough terms to be readily understood by any patient layman.
Dawkins provides many biological examples to illustrate and explain his argument. About a quarter of the book is devoted to the common bat that uses a highly sophisticated system of echolocation to image its surroundings and its prey. It is much like a sonar system, or like radar using high frequency sound waves rather than electromagnetic radiation. Several other bird species utilize similar systems of echolocation and it has also been carried to a high degree of sophistication in whales and dolphins. Dawkins uses these examples to illustrate the idea of convergence: that independent lines of evolution have, in many cases, converged from different starting points to a similar endpoint, in this case echolocation. The same is true of vision and the eye, a capability that has evolved separately and independently several times. These are cited as illustrations of the power of natural selection to produce good designs.
Such designs cannot occur in a single step, as Dawkins shows, since such a step would indeed be so improbable as to be impossible, as Paley argued. But Dawkins makes a case for the evolution of the eye, for example, in perhaps a thousand steps over many thousands of generations. The key is the eons of geological time and the hundreds of thousands of generations available for development of biological complexity in very small steps.
Dawkins provides the best explanation I have seen of how random mutations and natural selection can lead to a new species. The key is geographical separation of a single species population into two or more groups in different environments. Each group undergoes small changes through natural selection and adaptation to their differing environments. After hundreds or thousands of generations the groups have evolved in different directions in small discrete steps, until they have become different species. It they were then rejoined they would have become incapable of reproduction due to their genetic differences.
Dawkins addresses some of the differences among biologists regarding details of evolution, and argues that some are wrong, while others are just minor differences within a general acceptance of neo-Darwinism and natural selection. For example, he argues very effectively that Lamarkian selection is not a valid theory. Lamarkian evolution is the idea that acquired characteristics are passed on to the next generation, such as giraffes getting longer and longer necks as they reach for higher leaves on taller trees.
As another example, in a chapter called Puncturing Punctuationism, he discusses punctuated equilibrium in detail, and presents scathing ridicule of how punk eek has been seized upon and misrepresented by journalists and creationists. Properly understood, there is little disagreement between the gradualists and the idea by Eldridge and Gould that the fossil record suggests long periods of stasis with occasional bursts of relatively rapid evolution and appearance of many new species. He explains in detail that punctuated equilibrium is not inconsistent with neo-Darwinian natural selection, and should be seen only as a possible refinement of Darwins theory. He also offers some thoughts on other possible explanations for the apparent gaps in the fossil record.
In a chapter called The One True Tree of Life he discusses the great help that evolution offers to the science of Taxonomy---the science of classification and relationships between all living things. The idea of a nested hierarchy and its relationship to evolution is discussed in detail. There are several schools of thought among taxonomists, also called cladists, and Dawkins shows special scorn for one particular group called transformed cladists. Nelson and Platnick of the New York American Museum of Natural History have written that Darwinism---is a theory that has been put to the test and found false. They are prominent biologists and it is clear that Dawkins is VERY annoyed by them and seeks to invalidate their unorthodox view.
The final chapter of the book is called Doomed Rivals, and here Dawkins discusses and discredits a few non-Darwinian theories of biology including
Lamarkism, neutralism, mutationism, and creationism. He says that no serious biologist doubts that evolution has happened, that all living things are related, and that all living things have a common ancestor. His argument is generally that neo-Darwinian natural selection is a far better explanation of how evolution works than any of its rivals.
The ideas of creation science or creationism based on a 6000-year-old earth, and fiat creation of all living things would require invalidating every natural science, and cannot be taken seriously as science, or as a valid explanation of life. Modern theologians (and most Christians) do not support ideas like creation science, but rather are more likely to assign to God a role of guiding the quite well-proven fact of evolution. Dawkins main criticism of this view is that it assumes the prior existence of the thing we are trying to explain, namely organized complexity.
In this book Dawkins strongly supports his contention, which he expresses this way in his final paragraph:
---slow, gradual, cumulative natural selection is the ultimate explanation for our existence. If there are versions of the evolution theory that deny slow gradualism, and the central role of natural selection, they may be true in particular cases, but they cannot be the whole truth, for they deny the very heart of the evolution theory, which gives it the power to dissolve astronomical improbabilities, and to explain prodigies of apparent miracle.
It is a powerful and very readable book, strongly recommended for anyone who wants to understand the evolution theory of the origin of life, and the strong science that supports it.
For anyone interested in a critique of many of these ideas I suggest the book The Biotic Message by Walter Remine.