Thursday, July 20, 2006

"Instant" Evolution Seen in Darwin's Finches, Study Says #3

"Instant" Evolution Seen in Darwin's Finches, Study Says, National Geographic, Mason Inman, July 14, 2006 ...

[Graphic: Character Displacement - Darwin's finches, Dr. Robert Rothman, Rochester Institute of Technology.

Continued from part #2.]

Their [Peter and Rosemary Grant's] results appear in this week's issue of the journal Science. For both finch species, the researchers note, feeding is a trade-off between effort and payoff. [How profound! That is the same for every species. It is a basic (indeed commonsense) principle of ecology that if the "effort" (energy expended to obtain food, live and reproduce, etc) is greater than the "payoff" (energy obtained from the food), then if that continues, the organism will die. It is also a basic principle of ecology that if two species compete for the same limited resource in an ecosystem, then one or both species have to either "partition" that ecosystem by finding a different niche within it, or migrate to another ecosystem, or one goes extinct in that ecosystem.]

The birds generally prefer to eat larger seeds, which are harder for their nutcracker-like beaks to break open but hold a bigger reward inside. The bigger the bird's beak, the easier it is to crack open the seeds' coatings. The already smaller-beaked medium ground finch couldn't keep up with the newly arrived large ground finch, which is about twice as big and dominates feeding grounds. Apparently in response, the medium ground finch evolved to have an even smaller beak, making the species more adept at eating small seeds that didn't interest the larger finch. [Note again the Fallacy of Equivocation in the use of the word "evolved" for what is a minor adjustment of a population to its reduced available resources in a tiny (34 Ha = 84 acres) volcanic island ecosystem.]

"This is a phenomenon known as character displacement," Peter Grant said. "It is a very important one in studies of evolution, because it shows that species interact for food and undergo evolutionary change which minimizes further competition." [Grant makes it sound like a big deal, and maybe it is for a Darwinist who is hard up for evidence! But my biology and ecology textbooks cite as the "One of the best examples of character displacement" the beaks of these very finches on Daphne Major island, going back at least to the 1980s:

"Character Displacement When newly developed species come into contact again, competition can cause them to become more phenotypically different from one another. This process, called character displacement, is again exemplified by Darwin's finches. There are three species of ground finches, G. fuliginosa, G. fortis, and G. magnirostris, with bills adapted to feeding on small-, medium-, and large- sized seeds, respectively .... When all three species occur on the same island, they do not mate with each other and their bill sizes (beak depth) are quite distinctive. However, when G. fortis and G. fuliginosa are on separate islands, their bills tend to be the same intermediate size because there is no selection pressure to have larger or smaller beak size, perhaps because of lack of competition from other species." (Mader, S.S., "Biology," [1985], Wm. C. Brown Co: Dubuque IA, Third Edition, 1990, p.325)

"One of the best examples of character displacement involves the small and medium ground finches (Geospiza fuliginosa and Geospiza fortis) of the Galapagos studied by David Lack (1947). ... How many other clear-cut examples of morphological character displacement are known? Their answer is, surprisingly few." (Brewer, R., "The Science of Ecology," [1988], Saunders College Publishing: Ft. Worth TX, Second Edition, 1994, p.290).

The researchers say they have seen other types of evolution in action in Galápagos finches before. [There is no reason to deny that this is an example of "character displacement"in action, but that does not mean it is "evolution in action", unless one either: 1) defines "evolution" as any change in a population (in which case it is defining "evolution" so broadly that it cannot be false-and therefore is not science); 2) or makes the assumption that the process labelled "evolution" which varies the beaks of finches, is the same process labelled "evolution"that brought about finches, birds, and all of life in the first place (in which case it is just that: an assumption that has yet to be demonstrated-and therefore is not yet science)!]

But this was the strongest shift they've seen in their 33 years of study, the scientists say. [Which, quite frankly, is not much, however heroic their dedication to Darwin's cause-although a couple of professorships at Princeton University could be regarded as ample reward!

ID biologist Jonathan Wells notes that the Grants are prone to "exaggerating the evidence" in that "they have tried to make more of their work than the evidence warrants" and "this exaggeration [of the truth] seems to characterize many claims for Darwin's theory":

"As examples of the origin of species by natural selection, however, Darwin's finches leave a lot to be desired though this hasn't stopped some people from using them as examples anyway. But the only way they can do this is by exaggerating the evidence. ... Thanks to years of careful research by the Grants and their colleagues, we know quite a lot about natural selection and breeding patterns in Darwin's finches. And the available evidence is clear. First, selection oscillates with climatic fluctuations, and does not exhibit long-term evolutionary change. Second, the superior fitness of hybrids means that several species of Galapagos finches might be in the process of merging rather than diverging. The Grants' excellent field work provided us with a good demonstration of natural selection in the wild-far better than Kettlewell's peppered moths. If the Grants had stopped there, their work might stand as an example of science at its best. Yet they have tried to make more of their work than the evidence warrants. In articles published in 1996 and 1998, the Grants declared that the Darwinian theory of the origin of species `fits the facts of Darwin's Finch evolution on the Galapagos Islands,' and that `the driving force' is natural selection [Grant, P.R. & Grant, B.R., "Speciation and hybridization in island birds," Philosophical Transactions of the Royal Society of London B, Vol. 351, 1996, pp.765-772; Grant, P.R. & Grant, B.R., "Speciation and hybridization of birds on islands," pp. 142-162 in Grant, P.R., ed., "Evolution on Islands," Oxford University Press: Oxford, 1998, p. 155]. This claim was echoed by Mark Ridley in his 1996 college textbook, Evolution [Ridley, M., "Evolution," Blackwell Science: Cambridge MA, Second Edition, 1996, pp.570-571]. Like the Grants, Ridley extrapolated the increase in beak size after the 1977 drought to estimate the time it would take to produce a new species. This `illustrates how we can extrapolate from natural selection operating within a species to explain the diversification of the finches from a single common ancestor.' Ridley concluded: `Arguments of this kind are common in the theory of evolution.' Indeed. But arguments of this kind exaggerate the truth. And this exaggeration seems to characterize many claims for Darwin's theory. Evidence for change in peppered moths is claimed as evidence for natural selection even though the selective agent has not been demonstrated. And evidence for oscillating natural selection in finch beaks is claimed as evidence for the origin of finches in the first place. Apparently, some Darwinists are prone to make inflated claims for rather meager evidence." (Wells, J., "Icons of Evolution: Science or Myth?: Why Much of What We Teach About Evolution is Wrong," Regnery: Washington DC, 2000, pp.173-174)

Indeed, as Wells points out, no less than the National Academy of Sciences itself "exaggerate[s] the evidence" of Darwin's finches, calling them "`a particularly compelling example' of the origin of species," despite the fact that the Grants themselves have admitted that some of the 14 species of finch can interbreed and may in fact be hybridising back into fewer species:

"Writing in Science in 1992, the Grants noted that the superior fitness of hybrids among populations of Darwin's finches `calls into question their designation as species.' [Grant P.R. & Grant B.R, `Hybridization of Bird Species,' Science, Vol. 256, 1992, pp. 193-197] The following year, Peter Grant acknowledged that if species were strictly defined by inability to interbreed then `we would recognize only two species of Darwin's finch on Daphne,' instead of the usual four [Grant P.R., "Hybridization of Darwin's finches on Isla Daphne Major, Galapagos," Philosophical Transactions of the Royal Society of London B, Vol. 340, 1993, pp.127-139]. `The three populations of ground finches on Genovesa would similarly be reduced to one species,' Grant continued. `At the extreme, six species would be recognized in place of the current 14, and additional study might necessitate yet further reduction." (Wells, 2000, pp.172, 312n)

But what is reprehensible dishonesty (unless it is collective self-deception), is the NAS's claiming that "a single year of drought on the islands can drive evolutionary changes in the finches" such that "a new species of finch might arise in only about 200 years" but omitting to mention that "selection was reversed after the drought, producing no long-term evolutionary change," which as Phillip E. Johnson noted in the Wall Street Journal, "When our leading scientists have to resort to the sort of distortion that would land a stock promoter in jail, you know they are in trouble":

"Does the National Academy of Sciences endorse `arguments of this kind' that exaggerate the evidence? A 1999 booklet published by the National Academy describes Darwin's finches as `a particularly compelling example' of the origin of species. The booklet goes on to explain how the Grants and their colleagues showed `that a single year of drought on the islands can drive evolutionary changes in the finches,' and that `if droughts occur about once every 10 years on the islands, a new species of finch might arise in only about 200 years.' [National Academy of Sciences, "Science and Creationism: A View from the National Academy of Sciences," National Academy of Sciences Press:Washington, DC, Second Edition, 1999]. That's it. Rather than confuse the reader by mentioning that selection was reversed after the drought, producing no long- term evolutionary change, the booklet simply omits this awkward fact. Like a stock promoter who claims a stock might double in value in twenty years because it increased 5 percent in 1998, but doesn't mention that it decreased 5 percent in 1999, the booklet misleads the public by concealing a crucial part of the evidence. This is not truth-seeking. It makes one wonder how much evidence there really is for Darwin's theory. As Berkeley law professor and Darwin critic Phillip E. Johnson wrote in the Wall Street Journal in 1999: `When our leading scientists have to resort to the sort of distortion that would land a stock promoter in jail, you know they are in trouble [Johnson, P.E., "The Church of Darwin," The Wall Street Journal, August 16, 1999, pp. A14]." (Wells, 2000, pp.174-175) ]

Continued in part #3.

Stephen E. Jones, BSc (Biol).
`Evolution Quotes Book'

No comments: