Monday, February 27, 2006

Darwin was right - again?

An older news item from my backlog. My comments are bold and in square brackets. I have added to my original comments.

Darwin was right - again, Christian Science Monitor, February 09, 2006, Robert C. Cowen. Critics of evolution cite scientific debates to undercut Darwin's credibility. That strategy fails when research clears up some of the issues. Results from two separate research projects announced this week make that point. They deal with Darwin's controversial suggestion that new species can arise within an ancestral population even when there is no way to separate the diverging groups geographically. There's plenty of evidence that new species arise when segments of a single population become geographically separated, as Darwin also theorized. [This is false. Darwin downplayed the importance of geographical isolation:

"Darwin and Isolation ... Darwin's voyage on the Beagle gave him abundant opportunity to observe isolation at work: `barriers of any kind, or obstacles to free migration, are related in a close and important manner to the differences between the production of various regions ... on the opposite sides of lofty and continuous mountain-ranges, of great deserts and even of large rivers, we find different productions' (Darwin 1859:347). When chided by Moritz Wagner for underestimating the role of isolation in speciation, Darwin defended himself with the words: `It would have been a strange fact if I had overlooked the importance of isolation, seeing that it was such cases as that of the Galapagos Archipelago, which chiefly led me to study the origin of species' (F. Darwin 1888: vol. 3:159, letter of October 13, 1876). Yet, there is no doubt that Wagner's criticism was justified. Darwin admitted the occurrence of speciation on islands, but he emphasized again and again that incipient species could also evolve into full species without any spatial isolation: `I can by no means agree [with Wagner] that migration and isolation are necessary elements for the formation of new species.... I believe that many perfectly defined species have been formed on strictly continuous areas' (1872:106, 175). All the evidence that has accumulated since Darwin indicates that this assumption is unwarranted as far as higher animals are concerned. It is of more than historical interest to determine how Darwin arrived at his erroneous conclusion. " (Mayr E.W., "Evolution and the Diversity of Life: Selected Essays," Belknap: Cambridge MA, 1976, pp.120-121)

but (as usual) hedged his bets (so that his devotees could, no matter what turned out to be true, always claim "Darwin was right!":

"The majority of authors until fairly recently considered sympatric speciation, that is, speciation without geographic isolation, to be the prevailing mode of speciation. Such speciation is based on two postulates: (a) the establishment of new populations of a species in different ecological niches within the normal cruising range of the individuals of the parental population; (b) the reproductive isolation of the founders of the new population from individuals of the parental population. Gene flow between daughter and parental population is postulated to be inhibited by intrinsic rather than extrinsic factors. A rapid process of species formation is implied in most schemes of sympatric speciation. The concept of sympatric speciation is far older than that of geographic speciation and goes back to pre-Darwinian days. Darwin was rather vague on the subject and made no clear distinction between speciation through individuals and speciation through populations. In some of his statements he seems to give due recognition to the need for geographic isolation while in others he seems to ignore the geographical element altogether." (Mayr E.W., "Populations, Species and Evolution," [1963], Harvard University Press, Cambridge MA, 1974, Third printing, p.256)]

His other suggestion has lacked such evidence. It has remained what Axel Meyer and his colleagues at the University of Konstanz in Germany call "one of the most controversial concepts in evolutionary biology." They present in the journal Nature what they consider "a convincing case" that Darwin was right. They found their proof in Nicaragua's isolated volcanic crater Lake Apoyo. There, two species of cichlid fish - Midas cichlid and Arrow cichlid - live together. Detailed genetic, morphological, and ecological study confirms their relationship as separate species that evolved from a common ancestor. They live separate lives in the same geographical space. Misas feeds along the bottom. Arrow exploits the open water. The two do not interbreed. The researchers explain why they are convinced that the two species did not evolve elsewhere and then invade the lake after it formed about 23,000 years ago. Once the ancestral population was established, however, evolution progressed rapidly. The team estimates that the new species appeared in less than 10,000 years - a blink of the eye in geological time. Vincent Savolainen [spelling corrected] at Britain's Royal Botanic Gardens in Kew and nine fellow scientists find what they call "clear support" for Darwin's idea in palm trees on Lord Howe Island 600 miles east of Australia. Two species of the trees live side by side. The scientists find it "highly unlikely" that they evolved while geographically separated. There is strong reason to conclude that they evolved from a common ancestor without geographical separation. The two species appear to have gone separate ways because they flower at different times. This may originally have been due to differences in local soil conditions. In their report on Nature's online publication site, the researchers say the flowering times of the two species correlate with their soil preferences. In the case of Lake Apoyo, the differences in the feeding habits of the fish may have provided the opportunity for those two species to diverge. There's a larger lesson in this scientific nitty-gritty. It's taken more than a century and a half to resolve what, for scientists, was an important controversy. Patient research finally paid off. Proponents of creationism theories plead that high school science classes should "teach the controversy." They have a point, although it is not the point they think they are making. There is no "evolution versus creationist" scientific controversy. It's a political and philosophical controversy. Yet evolutionary biology has plenty of genuine scientific controversy. If schools taught that kind of controversy and how patient research can eventually resolve it, classroom science would be enriched. ... . [See also ABC, New York Times & Science NOW. I have added the above to my "Problems of Evolution" book outline, PE 2.8.16 "Fallacies used to support evolution ... Irrelevant thesis" (ignoratio elenchi):


Here is another example of the fallacy of irrelevant thesis being used in support of evolution. Two cases of possible sympatric speciation (i.e. speciation without geographical isolation) are cited, it is declared that "Darwin was right - again," and then Intelligent Design's "teach the controversy" position is attacked, as though ID (or creationism for that matter) denies that speciation can occur (i.e. that a fish species can split into two fish species or a palm species can split into two palm species): [the above article] The relevant question is not whether Darwin's theory can explain these trivial and easy cases, but whether it can plausibly explain important and hard cases, like assembling "30 protein parts" into a rotary motor, complete with rotor, stator, O-ring, bushings, U-joint and drive shaft:

"In recent years, biologists have discovered an exquisite world of nanotechnology within living cells - complex circuits, sliding clamps, energy-generating turbines and miniature machines. For example, bacterial cells are propelled by rotary engines called flagellar motors that rotate at 100,000rpm. These engines look like they were designed by engineers, with many distinct mechanical parts (made of proteins), including rotors, stators, O-rings, bushings, U-joints and drive shafts. The biochemist Michael Behe points out that the flagellar motor depends on the co-ordinated function of 30 protein parts. Remove one of these proteins and the rotary motor doesn't work. The motor is, in Behe's words, `irreducibly complex'. This creates a problem for the Darwinian mechanism. Natural selection preserves or "selects" functional advantages as they arise by random mutation. Yet the flagellar motor does not function unless all its 30 parts are present. Thus, natural selection can `select' the motor once it has arisen as a functioning whole, but it cannot produce the motor in a step-by-step Darwinian fashion. Natural selection purportedly builds complex systems from simpler structures by preserving a series of intermediates, each of which must perform some function. With the flagellar motor, most of the critical intermediate structures perform no function for selection to preserve. This leaves the origin of the flagellar motor unexplained by the mechanism - natural selection - that Darwin specifically proposed to replace the design hypothesis." (Meyer S.C., "Intelligent design is not creationism," Daily Telegraph, 28 January 2006)

That is what ID means by a "controversy"! The fact that Darwinists always point to easy cases to confirm their theory and never to hard cases (like the bacterial flagellar motor) to severely test and falsify it, shows that they themselves lack confidence in Darwin's theory.

By the way, these two cases do not prove that "Darwin was right." First, there is no evidence that the natural selection of random micromuations (which is Darwin theory) was responsible for these two claimed speciations. Second, while Darwin downplayed the importance of geographic isolation (Origin of Species, 1872, 6th edition, pp.82, 100) - in which he was wrong by the way (Mayr E.W., "Evolution and the Diversity of Life: Selected Essays," Belknap: Cambridge MA, 1976, pp.120-121) - Darwin also specifically denied the importance for speciation of "any small isolated area, such as an oceanic island" (p.101. My emphasis) and stated that he believed "that largeness of area is still more important" (p.101)!]

Stephen E. Jones, BSc (Biol).
"Problems of Evolution"

"But quite other causes have concurred to produce the general and higher degree of interest felt in the theory beside the readiness with which it harmonizes with biological facts. These latter could only be appreciated by physiologists, zoologists, and botanists ; whereas the Darwinian theory, so novel and so startling, has found a cloud of advocates and opponents beyond and outside the world of physical science. In the first place, it was inevitable that very many half-educated men and shallow thinkers should accept with eagerness the theory of `Natural Selection,' or rather what they think to be such (for few things are more remarkable than the manner in which it has been misunderstood), on account of a certain characteristic it has in common with other theories which should not be mentioned in the same breath with it, except, as now, with the accompaniment of protest and apology. We refer to its remarkable simplicity and the ready way in which phenomena the most complex appear explicable by a cause for the comprehension of which laborious and persevering efforts are not required, but which may be represented by the simple phrase `survival of the fittest.' With nothing more than this, can, on the Darwinian theory, all the most intricate facts of distribution and affinity, form, and colour, be accounted for; as well as the most complex instincts and the most admirable adjustments, such as those of the human eye and ear. It is in great measure then, owing to this supposed simplicity, and to a belief in its being yet easier and more simple than it is, that Darwinism, however imperfectly understood, has become a subject for general conversation and has been able thus widely to increase a certain knowledge of biological matters : and this excitation of interest in quarters where otherwise it would have been entirely wanting, is an additional motive for gratitude on the part of naturalists to the authors of the new theory. At the same time it must be admitted that a similar `simplicity'-the apparently easy explanation of complex phenomena-also constitutes the charm of such matters as hydropathy and phrenology, in the eyes of the unlearned or half-educated public. It is indeed the charm of all those seeming `short cuts' to knowledge, by which the labour of mastering scientific details is spared to those who believe that without such labour they can yet attain all the most valuable results of scientific research. It is not, of course, meant to imply that its `simplicity' tells at all against `Natural Selection,' but only that the actual or supposed possession of that quality is a strong reason for the wide and somewhat hasty acceptance of the theory, whether it be true or not." (Mivart S.J., "On the Genesis of Species," Macmillan & Co: London & New York , Second edition, 1871, pp.12-13. Emphasis original)

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