Ian Musgrave posted Entry 2386 on June 18, 2006 04:26 PM.
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Ann Coulter is a “provocative” American conservative columnist (more what we Australians would call a “Shock Jock”) who has written a book titled “Godless: the Church of Liberalism”. Four of her chapters (8-11) are on evolution. Now, we know Coulter is going to be provocative, and no-one expects these chapters to follow the guidelines of the Journal of Molecular Evolution, but within the limitations of a popular book by someone who is not a biologist, how does she handle evolution?
Badly; really, really badly. As PZ Myers has just posted, she basically repeats every Creationist canard ever produced (she does the no transitional fossils argument on page 216), and even some that the creationists themselves have since abandoned such as the tautology argument (page 199). What she doesn’t get wrong is badly misrepresented. Behe, Dembski and Berlinksi are thanked fulsomely for their help with the evolution section (see Acknowledgments, page 303); they should hang their heads in shame.
As usual with Creationist writing, it requires far more space to explain why Coulter is wrong than it took her to make the creationist arguments in her original manuscript. To give you a flavour of how she handles evolution in general, I’ll look at her treatment of natural selection and peppered moths.
To start with, Coulter can’t even get the colour of the moths right, stating that a light grey moth was “magically transformed” into a slightly darker grey moth (chapter 9, page 236). The moths actually went from near white/light grey to black. You can see a picture of them, here. Replacing a population with the cc alleles (the genes that make white moths white) with a population which only has the CC alleles (the genes that make dark moths dark), is not magic, but standard population genetics.
Coulter gives a brief overview of the peppered moth story, obscuring things from the outset by describing it as “legend.” It’s not clear what exactly she thinks is “legend”, the rise in the dark form of the peppered moth, or the hypothesis that natural selection was involved.
I’ll give a brief overview, to put her inadequate account into perspective. After the industrial revolution, woods near industrial cites were heavily polluted by soot. The trunks and branches were turned black by soot fallout. Even the very ground was black. Peppered moths were pale grey moths with a sprinkling of dark speckles, which made them near invisible when resting on lichen-covered trees, or trees with pale bark such as poplars or birches. The first known dark colored peppered moth was found in 1848, well after the start of the industrial revolution, in Manchester, England. By 1895, 98% of the peppered moths in that area were dark. The increases in the dark form followed in a pattern that radiated out from Manchester. Similar changes were seen in industrial Europe and America. This was what was observed, and is not in any way “legend”. The pattern of spread of the dark form is consistent with a mutation that first occurred around Manchester and then spread due to natural selection (and we know that the dark form is due to a change in a single gene). Haldane formally proposed that is was due to natural selection, and Bernard Kettlewell took to the field to test the proposal.
Hmm, make an observation, form a hypothesis and test it. Now what does that sound like? Science perhaps? You wouldn’t know it from Coulter’s account.
Typically, Coulter misrepresents the significance of the peppered moth experiments. She loudly proclaims that the moths remained just moths. This is a standard creationist statement, and may be found on a number of creationist web sites. The purpose of Kettlewell’s and others experiments was not to study speciation, it was to determine if the changes in peppered moth genotypes was due to natural selection. Her statement is bracketed by hyperbole, claiming that the changes in the peppered moth are “not the sort of metamorphosis that turns a mosquito into a German shepherd” (Chapter 9, Page 356). Now, again I know Coulter is trying to be outrageous and provocative, but that is a wildly ignorant misrepresentation of evolution (see an appropriate definition here, and the TO-FAQ’s on evolutionary biology are always a good starting point for people not familiar with biology). Again, Behe, Dembski, and Berlinski, who are Coulter’s tutors, should hang their heads in shame. Behe especially, because he actually knows this account is false. Organisms don’t metamorphose, but each successive generation will leave offspring that are slightly dissimilar to the parent generation [see note], and, slowly by our standards, their remote descendent are phenotypically distinct. It took nearly half a billion years for an Amphioxus-like invertebrate to evolve into a dog, so we don’t expect these level of changes to be seen in our experiments. But that doesn’t matter to Coulter.
Evolutionists were so excited about the peppered moth’s changing hue, they couldn’t be bothered with testing the theory. It had to be true.
Now, again this is probably supposed to be cute outrageous hyperbole, but nevertheless let’s contrast this with what really happened. While the spread of the dark peppered moths was observed late in the 19th century and early in the 20th century, researchers were unsure of the physiological basis of the change. While Tutt proposed as early as 1896 that selective visual predation by birds was responsible for the change, it was not announced as “proof” of evolution (or natural selection). Lots of work had to be done. First, the genetic basis of the change had to be established (as it was with later experiments). Second, in the 1920’s and 30’s explanations that were not based on natural selection were explored (and rejected). Third, in 1924, Haldane’s quantitative theoretical paper was published, showing that the rise of the peppered moth was consistent with natural selection. So by the end of the 1930’s the basic genetics of the peppered moth had been sorted out, a quantitative theory established and most (but not all) alternative explanations eliminated. Still, no one ever said that the peppered moth story proved either evolution or natural selection.
Then the Second World War intervened. At the end of the Second World War, scientists could start their researches again, but slowly, due to the financial constrains in post war Europe and America.
It wasn’t until the early fifties that anyone thought to test the theory.
Well, as we have seen, people actually were working on the problem in various ways well before the 1950’s. Apart from World War II, there were practical considerations that delayed anyone doing a direct experiment. The actual collecting methods had to be refined so that statistical analyses of data could be performed. Bernard Kettlewell was a pioneer in using radioactive tracers to study ecological interactions, and he came to Oxford to work with another pioneer, E.B. Ford. Ford’s experimental procedures for statistically studying population genetics in wild populations developed in the late 1940’s, with Ford conducting his own experiments in quantitative release-recapture. This kind of thing was called “ecological genetics” and was started by a small group of scientists at Oxford who saw the need to apply the recently-developed science of population genetics to populations in the wild. Such experiments, involving replications and controls (not just going out and counting bugs) were large-scale and relatively expensive, making them not practical in the early post-war years.
At about this point, Coulter starts really going off the rails. First she describes Bernard Kettlewell, who was a Nuffield Research Fellow at the Department of Genetics and Zoology at the University of Oxford, as E.B. Ford’s “assistant”. He wasn’t. He was an independent researcher in his own right. Ford didn’t send him out. He developed and executed his own experimental protocol. Coulter even has Ford placing moths on tree trunks, when Ford was never involved in the experimental work (see below). This is inexcusably sloppy, and Behe, Dembski and Berlinksi should be cringing in embarrassment right now.
Coulter’s description of the experiments, undoubtedly exaggerated for provocative effect, completely misrepresents them. Coulter makes fun of peppered moths and the desegregation of U.S. public schools at the same time, saying,
“For two years black moths were bused out of the inner-city areas to the suburbs, while white moths were bused into the inner-city areas. Then both groups were monitored to see how long each survived. (Is it just me, or does this scenario sound oddly familiar?)
This clearly a deliberately tasteless joke [note2], but it is worth noting for the clueless that no dark moths were “bused” to suburban areas, nor were light moths “bused” to inner city areas. All of the experiments occurred in rural woodlands, not cities. The unpolluted woodlands were in a rural area away from industrial locations, while the polluted woodlands were rural but downwind of Manchester, and subjected to significant smog fallout. Black and white moths were both raised in the Department at Oxford, and transported to both sites from Oxford [note3].
But this is only part of the story, if you will bear with me for a moment. Kettlewell did several different experiments:
1. Direct observation and filming. Kettlewell and others observed birds eating moths directly off trunks of trees. This was done both in experiments in an aviary, as well as outdoor experiments in the polluted and unpolluted sites.
2. Camouflage rating. Kettlewell visually ranked the effectiveness of camouflage of moths on different backgrounds and compared the effectiveness of camouflage with predation rates both in an aviary and in the field.
3. Release-recapture experiments. Kettlewell marked and released both light-colored and dark moths early in the morning, and recaptured some the next night in both pheromone and light traps (using mercury-vapor lamps). In polluted woods, he and his assistants recaptured more dark moths than light-colored, whereas in unpolluted woods they recaptured more light-colored than dark coloured.
4. Geographical distribution. This is not an experiment per-se, But Kettlewell noted that the distribution of the dark moths in the country closely matched the areas of industrialization.
The release-recapture experiments are the ones that capture the most attention, but the direct observation experiments and aviary experiments also supported the results from the release-recapture experiments.
When the experiments were completed, Ford didn’t triumphantly announce the results. Instead, they were published by Kettlewell in peer-reviewed research journals, and then Kettlewell brought further attention to them via publications in Scientific American, and lecture tours. However, at no time did either Kettlewell or Ford claim that the observations “proved” evolution all by themselves, or that natural selection by visual bird predation was the only factor in the rise of the dark peppered moths (although it was considered the major factor). They did, however, note that they had experimental documentation of natural selection producing an adaptation in a wild population, and although such results are commonplace today, at the time it was one of the first instances of this kind of experimental work.
Indeed, when Kettlewell published his first, massive paper showing selective predation on poorly camouflaged moth forms in polluted woods the response was a bit ho-hum. It was his second paper, where famed ethnologist Nico Tinbergen actually filmed birds eating resting moths (and where the complementary data set, that dark moths were selectively predated in unpolluted woods was performed, along with a second replication of the study in polluted woods that addressed some criticism of the first study) that people sat up and took notice. Still, this didn’t stop people trying to replicate the data, in different localities and with experimental set-ups to address some limitations of the original studies. There have been at least 30 independent experimental replications of Kettelwell’s original experiments, and they all confirm his work.
Now Coulter goes seriously wrong, and starts flinging around baseless accusations of fraud.
It was so logical, so intuitive, and so fake…. American lepidopterist Ted Sargent and others pointed out that peppered moths do not rest on tree trunks, but on the undersides of high branches.
Unfortunately for Coulter, Peppered moths do rest on tree trunks as well as branches (see also Howlett and Majerus, 1987). In fact, they rest all over the trees, although most prefer trunk postions underneath branches. Bernard Kettlewell, a keen naturalist, noted this explicitly himself in one of his papers, which is why in his release-recapture experiments he released the moths on trunks and branches. It’s in the original papers, which for some reason none of the creationists bother to read. (Coulter herself uses only newspaper accounts and flawed popular books such as Icons of Evolution for her sources, and did not go to the original work herself). No fakery was involved.
It turned out Ford and his assistant had rigged the game by physically placing light moths on black tree trunks in the bright light of day – someplace the moths would never have been if left to their own devices.
Well, as noted above Ford never placed a single moth. Kettlewell and his assistants placed moths on trees before dawn, and let the moths take up their own positions on trunks and branches, and made sure they were all out of direct sunlight (not, “the bright light of day”). Thus, in these experiments the moths were released into areas naturally occupied by peppered moths, and thus the experimental results will be reasonably representative moths in the wild. In one experiment, Kettlewell let the moths fly to their own resting places of choice. Also, in the release-recapture experiments, Kettlewell picked up moths that had spent at least one day on trees in positions they had flown to and chosen of their own accord. No rigging involved.
Furthermore, other researchers have looked at the relationship between different resting sites. Howlett and Majerus (1987) have done a pilot experiment comparing predation of moths on exposed trunks with predation of moths in shadow at trunk-branch junctions, the major resting site found in field observations. Differential predation was still observed for moths placed at shadowed trunk-branch junctions. For example, in polluted woods, more pale moths were taken by birds than dark moths, regardless of whether they were on exposed trunks or shadowed trunk-branch junctions. So, not only was no fraud involved, but different experimental setups used by different researchers have confirmed the validity of Kettlewell’s work. Estimates of the strength of selection may vary between experiments, but the statistical support for hypothesis that moths are favored in environments where they better match the background is strong.
But what about those photos? The famous photos of the peppered moths were staged, often by literally gluing dead moths to tree trunks.
Yes, because they were illustrations of differential camouflage, and nothing more. It’s a lot easier to show that dark and light forms have differential camouflage by putting them side by side on the same surface than show multiple pictures. The pictures are not meant to “prove” that moths rested on tree trunks (which they sometimes do: see Majerus’s magisterial 1998 book for unstaged pictures of moths resting on tree trunks), or that natural selection occurs (just read the captions). They do graphically show something real, that light moths are very poorly camouflaged on trees darkened by pollution, and dark moths are poorly camouflaged on unpolluted trees.
So, no fraud, and results that have been independently confirmed by other experimenters while controlling for the very factors the Ms Coulter complains about. She would have found this out if she had read a skerrick of the original research in the area, or even just Majerus’s book. Unlike Coulter’s claims, scientists did not ignore the peppered moth. They were the ones that had done independent research to confirm Kettlewell’s work, who had definitive proof there was no fraud involved. But these hard-working folks, toiling in obscurity to add a little to human knowledge, get nothing but abuse from the creationists. No one attempted to ruin Sargent’s career (Sargent by the way did not expose a fraud) but his failure to conduct any statistically rigorous predation experiments on the peppered moth [note4] did cause him to be marginalized in the debate. In science, results count.
Peppered moths sleep during the day and fly by night; they do not normally alight on tree trunks.
The first point is irrelevant. While moths are sleeping, immobile on the surface of trees, hungry insectivorous birds are hopping all over the surfaces of trees seeking insects to eat. What use would cryptic colouration be to a flying moth, anyway – let alone a moth flying in the dark? The fact that creationists never stop for two seconds before they repeat other creationists’ inane ravings about the behavior of moths and birds shows that they have no scientific interest in the issue, and are simply trying to shout down uncomfortable scientific evidence with the creationist equivalent of attack ads.
Anyone who has actually sat down and watched birds hunting in the trees for even a small amount of time will realize that whether moths rest more on tree trunks or tree branches is a relatively minor issue. There is not some fantastic magical barrier that keeps birds from hunting on tree branches. Birds hunt on the trunks as well as on, and under, branches. Small forest birds like creepers are quite capable of walking around on vertical or upside-down surfaces. Here’s one example right here. And as for the moths, from listening to Coulter, one would get the impression that moths that aren’t resting on tree trunks simply disappear to a magical bird-free parallel universe during the day.
The Coulter quote just above, from her last comments on the peppered moth saga, sums up the rest of her approach to evolution; where it is not irrelevant, it is wrong. Sloppy research, outright errors, gross misrepresentations, and false accusations of fraud, Behe, Berlinski and Dembski should be thoroughly ashamed of their association with this book. But are they? Dembski at least is happy with this farrago of nonsense. Happy, with a book that falsely accuses honest scientists with fraud? So much for intellectual honesty.
Note: In the case of speciation by hybridisation, phenotypic change can be very rapid, but generally it is relatively slow.
Note2: Well, clearly to Americans, for we non-Americans, see this Wikipedia article on Bussing and Desegregation. It’s still a tasteless joke. I find it alternately amusing and irritating that Coulter and the ID types assign American political values to non-US scientists who are neither describable by, nor particularly care about, US political divisions. To describe either EB Ford or Bernard Kettlewell as “liberals” in Coulters sense is, frankly, mind-boggling. In Australia, our ruling conservative party is the Liberal Party, many of whom are proud to be small “l” liberals.
Note3: In order to have enough moths for a statisticaly rigorous analysis, Kettlewell bred massive numbers of the black and white forms of the Peppered moth in Oxford. This was a significant investiture of time and effort, yet Coulter doesn’t even attempt to understand the science, she just uses a carcature to score cheap rhetorical points.
Note4: Sargent actually did no experiments with the Peppered moth at all, but was arguing from feeding results on a completely different moth species (he didn’t do any predation work himself either).
H.B.D. Kettlewell, Heredity 9 (1955): 323-342.
H.B.D. Kettlewell, Heredity 10 (1956): 287-301.
J.A. Bishop & L.M. Cook, Scientific American 232 (1975): 90-99.
R. C. Steward, Ecological Entomology 2 (1977): 231-243.
C. A. Clarke, G. S. Mani & G. Wynne, Biological Journal of the Linnean Society 26 (1985): 189-199.
R. J. Howlett & M. E. N. Majerus, Biological Journal of the Linnean Society 30 (1987): 31-44.
B. Grant & R.J. Howlett, Biological Journal of the Linnean Society 31 (1988): 217-232.
M. E. N. Majerus, Melanism: Evolution in Action (Oxford: Oxford University Press, 1998)
Good Web sites not otherwise referenced in the main text.
Jim Mallet’s review, with a review of Judith Hoopers book which is used as a source by Ms Coulter.
Matt Young’s crtiques of Judith Hoopers book
A good Review by Moth Expert Bruce Grant
A fine Kettle of Moths Matt Young
Wikipedia article on Peppered Moths
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