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Peppered Moth Idolatry


The venerable peppered moth (Biston betularia) has popped up a couple of times in recent posts.  It seems that some of our Darwinian commenters (see, e.g., qwerty017 in comment [2] here) have not gotten the memo – the peppered moth myth has been completely exploded.  Don’t take our word for it.  Uber-Darwinist Jerry Coyne says in the November 1998 edition of Nature:  “For the time being we must discard Biston as a well-understood example of natural selection in action.”  Why else would the popular school text Biology pull its discussion of Biston as an example of “evolution in action”?


My purpose in this post is not, however, to re-hash the vast debunking literature.  Instead, when I did a brief internet search on the subject I was intrigued by an astonishing display of Darwinian “It’s just gotta be” psychology on display in this New Scientist article.  After rehearsing the history of the controversy and admitting that Kettlewell’s iconic experiments were seriously flawed, the author reports on recent attempts by Michael Majerus to rehabilitate the myth.  But having been burned once, many scientists are reluctant to re-admit Biston to the pantheon of evolution icons.  And this is where it gets interesting.  Near the end of the article the author admits:

Majerus’s study also leaves a long-standing problem unsolved. For reasons that are not clear, the frequencies of dark and light moths do not always correlate with the level of pollution. In East Anglia, for example, dark moths have always been relatively common despite low pollution levels.

But, says the author, while “these are legitimate problems that require scientific explanations,” they “do not point to a fundamental problem with the peppered moth story,” and he concludes: 

Anti-evolutionists will continue to suggest [the peppered moth story is controversial], of course, but as far as Majerus and others are concerned their claims have been debunked and the peppered moth should be reinstated as a textbook example of evolution in action.

The fact that experimental data that is admitted by all observers flatly contradicts the myth is not a “fundamental problem,” and only benighted “anti-evolutionists” would resist re-admiting the peppered moth as a textbook example of evolution.


The peppered moth story, even had it been true, never demonstrated macro-evolution unless one was already a true believer, but it did serve to confuse generations of schoolchildren.  The point of this post has nothing to do with whether the story is true though.  As I said, the de-bunking literature is already vast.


No, this post is about the psychological phenomenon known as “cognitive dissonance,” the ability to hold two mutually exclusive ideas at the same time.  Look at the quoted language again or, better yet, go back and read the whole story.  In one paragraph the author admits that nowadays the peppered moth story is controversial even among Darwinian scientists.  Then, only a couple of paragraphs later, the author boldly petitions the scientific community to readmit the story to the canon, because only knuckle-dragging, snake-handling fundies have the least doubt about it.  Rarely are we privileged to see such a crystalline example of cognitive dissonance in action.

van, I would say there are valid examples like the trypsinogen gene in Antarctic notothenioid fish. Also, with the same creature it turns out that only 1% of its blood is actually made up of cells, which is far from normal like the 40% cell content of human blood. By carrying fewer cells, the resulting lower-viscosity blood continues to flow even with the bitterly cold sea temperatures. But this is a story of degeneration, not of innovation. This is like a bridge that is blown up because it is beneficial in an environment of war. Darwinists need constructive beneficial modifications on a regular basis. It is far easier to tear down than it is to build. This beneficial mutation is destructive in that while all other fish have two globin genes--alpha1 and beta globin--it turns out that ice fish carry a partially deleted copy of alpha1 and lack the beta globin gene altogether. These deletions are inextricably linked to its lower blood viscosity and have seemingly produced a key adaptation. In any case, these examples "should" provide no solace for Darwinists since they are limited in scope and do not involve IC/CSI. Patrick
The accepted definition of evolution within modern biology is a change in the allele frequency within a population. Thus, evolution is going on all the time throughout the world in nearly every population though the changes are trivial. There is no need for new genetic material to appear though it can appear through recombination and some mutations. Thus, the change in colors in the moths fit the definition of evolution even though it can switch back and forth and no real change has taken place. Using the moths as examples of evolution is deceptive because the real debate is over macro evolution and the change in color is so far from that, the use of it is a joke. So I would not question the moth changes and their causes but as said above point out that "Is this all you got." jerry
Interesting that this has come up again. I had some correspondence with Majerus a few years ago when he was working on his new efforts to rehabilitate the peppered moth icon. The peppered myth, excuse me, moth, is pretty much a joke, as far as meaningful science goes. However, even if we take every alleged fact from Kettlewell to the present as gospel, the ultimate lesson we learn from the peppered moth is the following: Organisms have the ability to adapt to temporary conditions, while ultimately resisting fundamental change. That is the sum and substance of the objective lesson that can be gleaned from the peppered moth. Eric Anderson
Why do so many people on this forum still believe in "evolution" of any kind? (I'm talking of the IDists in here)....in order for "evolution" to happen there must be new genetic material introduced to the gene pool, then to be selected by differential survival/reproduction. Not only must a genetic change occur (random mutation) but also natural selection must be the cause of change in the population. But there is no new genetic material associated with the peppered moth phenomenon -- both versions were already there in the population. As, Maciej Giertych, a population geneticist, was quoted above: “Natural selection does not provide any new genetic information. And for evolution we need new genetic information." Yet there is none there. And the other "icon" of evolution -- Darwin's finches -- there is no mutation there either...no genetic change is involved in the finch beaks being altered...therefore, once again, no evolution. In fact, evolution doesn't happen anywhere but in the minds of darwinists. van
The peppered moth is quite irrelevant as evidence for evolution. It's an excellent demonstration of the function of camouflage, but it begins and ends with moths with no new species being formed. Barb
Are you going to simply zap everybody who politely and respectfully disagrees with you.
I won't, but since you decided to throw insults in your last couple comments out you go. Instead of zapping your offending comment I left the insult intact since it's relatively mild. Patrick
No wonder they call you IDiots...it's well-deserved colin_evans101
"Bueller_007 and MaxEntropy are no longer with us." About time. There may not be any ad hominems, but I share Barry's exasperation with such apparent deliberate obfuscation of the issue, or just lack of understanding. DaveScot wouldn't have had even this much patience. Enough is enough. magnan
Joseph as a point. Let 'em have it. Anyone who has sincere intentions of learning the truth (knuckle dragging fundie or not) would have to ask (as has been) "Is this the best you've got to offer?" Jack Golightly
Bueller_007 and MaxEntropy are no longer with us.
How come? Did they post something inflammatory that has since been deleted? Praxiteles
Bueller_007 and MaxEntropy are no longer with us. Barry Arrington
MaxEntropy, get a clue. Pace your comment, the article itself points out that there are major problems with the effort to rehabilitate the myth. So, yes, you do indeed seem to be impervious to facts. Secondly, if the Darwinists were being honest and saying that the moth might represent an example of micro-evolution, I would agree with you. They are not. HELLO IN THERE! (he says as he knocks on Max’s head with his knuckles). The whole point of the myth is a lie! The Darwinists point to a supposed fluctuation in the distribution of dark and light moths, each of which were there to begin with, and claim it is evidence for how the moths came into existence in the first place. As other commenters have asked, “Is this the best you’ve got”? Why don’t you lay on us some of that overwhelming evidence you are always crowing about? You don’t see how this is cognitive dissonance? Let me get this straight. The author admits there are major problems with accepting the moth as an example of even micro-evolution, and yet he wants the moth added back to the canon of supporting evidence for macro-evolution. If you don’t understand that that is cognitive dissonance, you are hopeless, because it does not get any clearer than that. Barry Arrington
I don't get it. The peppered moth is an example of micro evolution, and as far as I can tell from the new research it has been substantially confirmed in the sense that the moths colour affects its vulnerability to predation and that in turn affects reproduction rates. As others have pointed out "ID has no quarrel with micro evolution" and this is an example of that process and as such an example of evolution in action. Now you might legitematly point out that this IS only an example of micro evolution, and even demand that this be pointed out in the textbooks but, AS an example of micro evolution, I really can't see the problem with it from an ID perspective. "The fact that experimental data that is admitted by all observers flatly contradicts the myth..." I read the article, and yours and I just don't see how you got there, or quite how this article qualifies as cognitive dissonance? And before you launch at me with presumptive insults about me being "A true believer" who's "beliefs are impervious to evidence and logic" I'd like to say that I constantly engage in a "critical examination of ones (my and others) opinions" and I'm constantly "considering the evidence and thinking for ones self" MaxEntropy
Critiacrof said:
To bad some people don’t realize the difference between natural selection and the entire evolution process. The point is that both types of moths where there from the beginning. No new genes formed that changed the color. Even if a new color would appear thanks to a mutation that could be because the mutation disables a certain “color gene”. Real evolution would be a moth that develops a gene that makes the moth invisible at will and that that type of moth would be unable to reproduce with the old type of moth.
That's essentially just what I was thinking. Notice that in the Peppered-Moth case, and even in Darwin's Finches case, all of the animals already had the object/trait that became dominant. The moths already had various colors, and even were the experiment shown to be accurate of reality, it would only show that, generally, animals less fit to survive don't survive. In the case of the birds, the birds' beaks already existed, and those just varied genetically and under certain circumstances birds with specific beaks were "selected" over others. However, in neither case does something new appear via natural selection or random mutation. The moths didn't gain new colors (and even if they did, this isn't so special, as color changes happen in many, many animals), and the birds already had beaks. What would be truly impressive is if the moths developed hands and fingers on their legs, and the birds grew fir instead of feathers and evolved a different lung system. New genetic information would be required for the above cases. Unfortunately though, for believers of Neo-Darwinism, such new genetic information, arising via natural selection or random mutation has never been observed. As, Maciej Giertych, a population geneticist, put it: "Natural selection does not provide any new genetic information. And for evolution we need new genetic information. Darwin assumed that the increase in information comes from natural selection. But natural selection reduces genetic information, and we know this from all the genetic studies we have done. Generally we are afraid of mutations ... So we are avoiding mutations because we know that mutations spoil. We do not know of any mutation that is positive. We have never observed a change, a genetic change by mutation, that has produced something new and positive." Information (highly specified information, such as a language or a computer code), however, is known to be created only through an intelligent agent. Considering we find information within DNA, only much more advanced then our own, I see no reason to posit random mutations or natural selection. Intelligence is the most obvious, and intuitive explanation. Not to mention information being created through intelligence has been observed over and over again throughout history and everyday life. ID theorists have evidence of this, whereas Neo-Darwinian believers lack evidence for their suggestion.
Also saying that (natural)selection is (part of) evolution and therefor proves evolution is the same as saying that Santa exist because we get presents.
lol This made me laugh! Domoman
Croizat and Bueller_007, I take it from your comments that you are true believers in NDE. Good for you. Being a true believer saves all the effort one would otherwise have to expend actually considering the evidence and thinking for ones self. I imagine it is also very comforting for you to know that because your beliefs are impervious to evidence and logic, you will never have to experience the emotional turmoil often associated with critical examination of ones opinions. Neither of your comments has anything to do with the thrust of the post, which, because you are true believers, you simply ignored. You both imply that I concealed Coynes later views. First, Coynes later statements were not motivated by the fact that the peppered moth myth has been rehabilitated. As the story itself points out, despite all of Majerus’ efforts, it has not. Secondly, Coynes later statements are irrelevant to my main point. Thirdly, Coynes later statements were not a function of the evidence; they were motivated by the howls of indignation of NDE fundies that accompanied Coynes matter-of-fact recitation of the facts. And finally, I did not conceal anything as you imply. Because I linked to the full story, Coyne’s later statements were only a click away from my post. Barry Arrington
Why did you cut off the end of the Coyne's quote from the original article, Barry? "First, for the time being we must discard Biston as a well-understood example of natural selection in action, ***although it is clearly a case of evolution.***" Bueller_007
ID has no quarrel with micro evolution and that is all the peppered moths ever were. Whether in fact they did change color or not is besides the point. It is an example of micro evolution and a trivial example at that. So ID enthusiasts embrace the peppered moth story whether it is true or false as just another example of micro evolution with which ID is perfectly comfortable. Again we must emphasize that ID has no problem with micro evolution. ID has major problems with macro evolution. In fact there is not one case of macro evolution ever demonstrated which is why the pro NDE people focus on peppered moths and finch beaks. jerry
Um, Jerry Coyne reversed himself after Majerus's new results were reported. So quoting Coyne's old opinion without mentioning his new one is not such a good argument. Croizat
To bad some people don't realize the difference between natural selection and the entire evolution process. The point is that both types of moths where there from the beginning. No new genes formed that changed the color. Even if a new color would appear thanks to a mutation that could be because the mutation disables a certain "color gene". Real evolution would be a moth that develops a gene that makes the moth invisible at will and that that type of moth would be unable to reproduce with the old type of moth. Also saying that (natural)selection is (part of) evolution and therefor proves evolution is the same as saying that Santa exist because we get presents. critiacrof
On the other hand, the wikipedia entry for "peppered moth" indicates that all is well with the moth experiments:
Despite some valid criticisms of the early experiments, there has been no evidence of fraud and subsequent experiments and observations have clearly shown the phenomenon and supported its initial explanation.
If NDE is supported by "overwhelming evidence", then why do they keep the peppered moth story on life-support? If they are so attached to evidence that is "fake but accurate", then people will conclude that they are bluffing about the weight of evidence supporting their theory. russ
If moths of a different color surving at different rates in different environments is evidence for evolution, and it is one of the covetted examples, I say let them have it. Then all anyone has to do is say one of their best examples involves only coloration differences and that is about all they can demonstrate. So what do you think of evolution now? Joseph
If data do not correspond with theory, so bad for data! Shazard

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