Creationists lose key Texas case, peppered moths

Texas creationists have lost a key case in their campaign against biology textbooks. No, not in the courts.

Peppered moth, lighter colored, against pollution-colored tree; photo by John S. Haywood

They lost their case in nature. In the wild.

Colors changed in peppered moths because of natural selection, a new study confirms. This strikes a serious blow to one of the chief creationist complaints about how evolution is discussed in biology textbooks. Photo at right showing two moths, of the light and dark forms, against pollution-colored tree bark; photo by John S. Haywood, from Kettlewell’s paper, via Encyclopedia Britannica.

British moth researcher Michael Majerus reported that a seven-year research project has confirmed the 1950s work of Bernard Kettlewell: Changes in the coloring of peppered moths is a result of natural selection at work. Majerus is the researcher whose work was mischaracterized by creationists as having questioned or disproven Kettlewell’s work, which showed that natural selection was responsible for a change in the color of most peppered moths in Britain.

Majerus reported his study at a biologists’ meeting in Sweden on August 23. “We need to address global problems now, and to do so with any chance of success, we have to base our decisions on scientific facts: and that includes the fact of Darwinian evolution. If the rise and fall of the peppered moth is one of the most visually impacting and easily understood examples of Darwinian evolution in action, it should be taught. It provides after all: The Proof of Evolution.”

The news is particularly devastating for evolution opponent Jonathan Wells, who has campaigned against evolution in Ohio, Pennsylvania, Texas and other places on the basis of his claims that the moth research was faulty. This claim is the backbone of Wells’s book, Icons of Evolution. Majerus’s new paper requires major sections of Wells’ book to be discarded.

The news cuts out the heart of the case for discussing the weaknesses of evolution theory, and instead makes the point that students need to learn the theory and its strengths first, as current Texas law requires.

Berkeley’s Nick Matzke, formerly of the National Center for Science Education (NCSE), relates the story at Panda’s Thumb:

The ID movement hasn’t had many successes, but one area where they did pretty much succeed in causing considerable havoc was the classic textbook example of natural selection in action: the change in color of peppered moths (Biston betularia) from peppered white, to black, and back to peppered white again. Through a series of accidents that is still difficult to understand, the idea got started in the late 1990s that leading peppered moth researcher Michael Majerus had debunked Bernard Kettlewell’s famous study confirming the old hypothesis that the change in peppered moth color was due to selective predation of conspicious moths by birds.

This confusion, minor by itself, was massively magnified when the ID/creationists picked it up and spread it far and wide. In the 1970s-1980s, creationists used to just resort to traditional obfuscation when confronted with natural selection producing a the “designed-looking” adaptation of moth camouflage to match their changing background – creationists would just reply “they’re still moths”, purposely avoiding the point of the peppered moth example. But once they heard that Kettlewell’s research and hypothesis were in trouble, they declared the example a fraud, the illustrative photos a dastardly fraud, and told the world that the biology textbooks were lying to the children and that the ID movement’s quack science should be given a place in schools to balance things out. I think Jonathan Wells probably considered the alleged downfall of the peppered moth his career achievement.

Majerus’s paper will be published later; I have linked to the text of his PowerPoint presentation. Matzke contacted Majerus, who said he will put up the photos and the entire PowerPoint presentation soon.

The story of the peppered moth was a favorite of Texas State Board of Education members during the past round of discussions over biology textbooks, including new chairman Don McLeroy. Perhaps this dramatic repudiation of a key part of the case for intelligent design will give board members pause before they ask that the evidence for evolution be diluted.

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3 Responses to Creationists lose key Texas case, peppered moths

  1. [...] See earlier post, here, “Creationists lose key Texas case.” [...]


  2. Ed Darrell says:

    If it were accurate that all evolution happens because of a loss of genes, you’d have a point. The very first record of clear evolution under watch, however — the rise of the salt grass Spartina townsendii in the Thames River circa 1867, involved a near-doubling of the chromosome count for the plant over the two species suspected of being the parent. Many other cases of increased chromosomes, new genes, new gene combinations, and totally spontaneous changes or “sport” mutations, are recorded throughout zoology and botany. Red grapefruit did not exist in any form prior to the 20th century. All red grapefruit today are the products of a spontaneous mutation a savvy farmer caught in the 1940s. Similarly, the mutation that makes mosquitoes absolutely immune to DDT did not exist in mosquitoes prior to the application of DDT — we have DNA samples to prove it. The application of DDT drove mosquitoes to rapid mutations, and one of those mutations included an ability to digest the poison rather than die from it. That mutation is now worldwide.

    Evolution by natural and sexual selection has been observed in real time to be the means by which evolution happens. Surely your Creator does not urge that we teach falsehoods. I know my Creator is quite put off by those who mislead children — something about a millstone around their necks.


  3. Justin says:

    A creationist, Edward Blyth, thought of the concept of natural selection 25 years before Darwin’s Origin of Species was published. But unlike evolutionists, Blyth regarded it as a conservative process that would remove defective organisms, thus conserving the health of the population as a whole. For example, the original dog/wolf kind probably had the information for a wide variety of fur lengths. The first animals probably had medium-length fur (LS). One form of the gene (L) carries instructions for long fur, the other (S) for short fur. So, we start with medium-furred animals (LS) interbreeding. Each of the offspring of these dogs can get one of either gene from each parent to make up their two genes. We see that the resultant offspring can have either short (SS), medium (LS) or long (LL) fur. Now imagine the climate cooling drastically (as in the Ice Age). Only those with long fur survive to give rise to the next generation. So from then on, all the dogs will be a new, long-furred variety. Note that:

    1. They are now adapted to their environment.

    2. They are now more specialized than their ancestors.

    3. This has occurred through natural selection.

    4. There have been no new genes added.

    5. In fact, genes have been lost from the population—i.e., there has been a loss of genetic information, the opposite of what microbe-to-man evolution needs in order to be credible.

    6. Now the population is less able to adapt to future environmental changes—were the climate to become hot, there is no genetic information for short fur, so the dogs would probably overheat.

    Creationists do not deny natural selection, but they oppose it being taught as the means by which evolution happens. Natural Selection is the amazing process our Creator desined to allow for change among kinds!


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