[Graphic: Only some of the ~350 dog breeds, The Blueberry Basket at Brock Farm, Maine]
A geneticist says he may have solved the mystery of how 350 breeds of dog evolved from a single ancestor, the grey wolf. Matthew Webster of the Smurfit Institute of Genetics at Trinity College, Dublin, and colleagues at Uppsala University, Sweden, say the domestication of dogs may be allowing them to override the natural laws governing evolution. They suggest natural selection, which ensures the survival of the fittest and weeds out genetic mutations that don't provide a survival advantage, was relaxed when dogs became domesticated. Living with people allowed harmful genetic variations to flourish that would never have survived in the wild. This interference with nature could also explain why domestic dogs developed an array of diseases such as cancer, heart disease and epilepsy. "Dogs exhibit more variation in size, appearance and behaviour than any other mammal, but the source of this huge diversity is something of a mystery," said Webster. "Dogs were domesticated from wolves very recently, on an evolutionary timescale, so all the variability seen in different dog breeds today has been generated in a relatively short time." Scientists are still puzzled as to how such a scale of development could have taken place in a relatively short evolutionary timescale of 15,000 years. ... "Living with humans means harmful mutations can still survive in dogs that wouldn't have been able to breed in the wild. Wolves ... would be less likely to survive if they had these mutations," he said. "It is possible that changes in lifestyle caused by dog domestication have allowed mutations to accumulate across the entire dog genome, contributing to the huge differences in appearance in today's dogs. This could also explain why so many diseases affect modern breeds, a consequence of the weaker natural selection. A lot of dog breeds now wouldn't survive if they weren't living with humans." His findings are published in Genome Research. ... [Darwin appealed to "man's power of accumulative selection", mentioning especially "the many breeds of dogs" as evidence that "the principle of selection, which we have seen is so potent in the hands of man, appl[ies] under nature":
"Let us now briefly consider the steps by which domestic races have been produced, either from one or from several allied species. Some effect may be attributed to the direct and definite action of the external conditions of life, and some to habit; but he would be a bold man who would account by such agencies for the differences between a dray- and race-horse, a greyhound and bloodhound, a carrier and tumbler pigeon. One of the most remarkable features in our domesticated races is that we see in them adaptation, not indeed to the animal's or plant's own good, but to man's use or fancy. ... when we compare the dray horse and race horse, the dromedary and camel, the various breeds of sheep fitted either for cultivated land or mountain pasture, with the wool of one breed good for one purpose, and that of another breed for another purpose; when we compare the many breeds of dogs, each good for man in different ways ... we must, I think, look further than to mere variability. We cannot suppose that all the breeds were suddenly produced as perfect and as useful as we now see them; indeed, in many cases, we know that this has not been their history. The key is man's power of accumulative selection: nature gives successive variations; man adds them up in certain directions useful to him. In this sense he may be said to have made for himself useful breeds. ... Can the principle of selection, which we have seen is so potent in the hands of man, apply under nature? I think we shall see that it can act most efficiently." (Darwin, C.R., "The Origin of Species By Means of Natural Selection," Sixth Edition, 1872, Senate: London, 1994, pp.22, 62)
Dawkins likewise cited "the change that man has wrought in a much shorter time by genetic selection of dogs," in "a few hundreds, or at most thousands, of years" as the same process of "real natural evolution" extrapolated over "several hundred million years" in order to explain "how ... our type of eye ... evolve[d] its present complexity and perfection from nothing":
"Eyes don't fossilize, so we don't know how long our type of eye took to evolve its present complexity and perfection from nothing, but the time available is several hundred million years. Think, by way of comparison, of the change that man has wrought in a much shorter time by genetic selection of dogs. In a few hundreds, or at most thousands, of years we have gone from wolf to Pekinese, Bulldog, Chihuahua and Saint Bernard. Ah, but they are still dogs aren't they? They haven't turned into a different 'kind' of animal? Yes, if it comforts you to play with words like that, you can call them all dogs. But just think about the time involved. Let's represent the total time it took to evolve all these breeds of dog from a wolf, by one ordinary walking pace. Then, on the same scale, how far would you have to walk, in order to get back to Lucy and her kind, the earliest human fossils that unequivocally walked upright? The answer is about 2 miles. And how far would you have to walk, in order to get back to the start of evolution on Earth? The answer is that you would have to slog it out all the way from London to Baghdad. Think of the total quantity of change involved in going from wolf to Chihuahua, and then multiply it up by the number of walking paces between London and Baghdad. This will give some intuitive idea of the amount of change that we can expect in real natural evolution." (Dawkins R., "The Blind Watchmaker," W.W Norton & Co: New York NY, 1986, p.40. Emphasis original)
But this article is saying that it was the absence of natural selection, i.e. "natural selection, which ensures the survival of the fittest and weeds out genetic mutations that don't provide a survival advantage, was relaxed when dogs became domesticated" (my emphasis) that has been the true cause of the variability in dogs. That is, all that the breeders did was, as Crick noted (like Darwin and Dawkins without realising its significance), was to preserve "the freaks of nature" thrown up when natural selection was relaxed:"
"If you doubt the power of natural selection I urge you, to save your soul, to read Dawkins's book. I think you will find it a revelation. Dawkins gives a nice argument to show how far the process of evolution can go in the time available to it. He points out that man, by selection, has produced an enormous variety of types of dog, such as Pekinese, bulldogs, and so on, in the space of only a few thousand years. Here `man' is the important factor in the environment, and it is his peculiar tastes that have produced (by selective breeding, not by `design') the freaks of nature we see preserved all around us as domestic dogs, yet the time required to do this, on the evolutionary scale of hundreds of millions of years, is extraordinarily short. So we should not be surprised at the ever greater variety of creatures that natural-selection has produced on this much larger time scale." (Crick, F.H.C., "What Mad Pursuit: A Personal View of Scientific Discovery," [1988], Penguin: London, 1990, reprint, p.29)
That is, the evidence of selective breeding is, that "natural selection" merely has a conservative role! It is mutations in the absence of natural selection that allowed the various breeds of dogs and other domestic animals and plants to appear and survive.
The analogy from selective breeding therefore is that it was not natural selection that created the eye (or indeed any of life's complex designs): it was mutations in the absence of natural selection that created them. And if undirected mutations could not plausibly create life's complex designs (I agree with Darwinists on that point), then that leaves directed mutations as the sole remaining cause!
As Sherlock Holmes observed, "when you have eliminated the impossible, whatever remains, however improbable, must be the truth":
"`How came he, then?' I reiterated. `The door is locked, the window is inaccessible. Was it through the chimney?' The grate is much too small,' he answered. `I had already considered that possibility.' `How then?' I persisted. `You will not apply my precept,' he said, shaking his head. `How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth? We know that he did not come through the door, the window, or the chimney. We also know that he could not have been concealed in the room, as there is no concealment possible. Whence, then, did he come?' `He came through the hole in the roof,' I cried. `Of course he did. He must have done so. If you will have the kindness to hold the lamp for me, we shall now extend our researches to the room above, - the secret room in which the treasure was found.'" (Doyle, A.C., "The Sign of Four," Penguin: London, 2001, pp.42-43. Emphasis original).
Stephen E. Jones, BSc (Biol).
`Evolution Quotes Book'
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