Tag Archives: Jonathan Wells

Did your science textbook teach that peppered moths prove evolution?

Here’s a post by Jonathan Wells at Evolution News, which re-caps the history of the peppered moths experiment.

Excerpt: (links removed)

The peppered moth story is familiar — even overly familiar — to most readers of ENV, so I will summarize it only briefly here. Before the industrial revolution, most peppered moths in England were light-colored; but after tree trunks around cities were darkened by pollution, a dark-colored (“melanic”) variety became much more common (a phenomenon known as “industrial melanism”). In the 1950s, British physician Bernard Kettlewell performed some experiments that seemed to show that the proportion of melanic moths had increased because they were better camouflaged on darkened tree trunks and thus less likely to be eaten by predatory birds.

Kettlewell’s evidence soon became the classic textbook demonstration of natural selection in action — commonly illustrated with photos of peppered moths resting on light- and dark-colored tree trunks.

By the 1990s, however, biologists had discovered several discrepancies in the classic story– not the least of which was that peppered moths in the wild do not usually rest on tree trunks. Most of the textbook photos had been staged.

In the 2000s the story began disappearing from the textbooks. British biologist Michael Majerus then did some studies that he felt supported the camouflage-predation explanation. But before he died of cancer in 2009, he only managed to publish a report of his study in the Darwin lobby’s in-house magazine Evolution: Education and Outreach. Now four other British biologists have presented his results posthumously in the Royal Society’s peer-reviewed Biology Letters. In an accompanying supplement, the authors presented their version of what they call “the peppered moth debacle.” And a debacle it certainly is, but not in the way they think.

According to Charles Darwin, natural selection has been “the most important” factor in the descent with modification of all living things from one or a few common ancestors, yet he had no actual evidence for it. All he could offer in The Origin of Species were “one or two imaginary illustrations.” It wasn’t until almost a century later that Kettlewell seemed to provide “Darwin’s missing evidence” by marking and releasing light- and dark-colored moths in polluted and unpolluted woodlands and recovering some of them the next day. Consistent with the camouflage-predation explanation, the proportion of better-camouflaged moths increased between their release and recapture.

Throughout the 1970s and 1980s, however, researchers reported various problems with the camouflage-predation explanation, and in 1998 University of Massachusetts biologist Theodore Sargent and two colleagues published an article in volume 30 of Evolutionary Biology concluding “there is little persuasive evidence, in the form of rigorous and replicated observations and experiments, to support this explanation at the present time.” (p. 318)

The same year, Michael Majerus published a book in which he concluded that evidence gathered in the forty years since Kettlewell’s work showed that “the basic peppered moth story is wrong, inaccurate, or incomplete, with respect to most of the story’s component parts.” (p. 116) In a review of Majerus’s book published in Nature, University of Chicago evolutionary biologist Jerry Coyne wrote: “From time to time, evolutionists re-examine a classic experimental study and find, to their horror, that it is flawed or downright wrong.” According to Coyne, the fact that peppered moths in the wild rarely rest on tree trunks “alone invalidates Kettlewell’s release-and-recapture experiments, as moths were released by placing them directly onto tree trunks.”

In 1999, I published an article in The Scientist summarizing these and other criticisms of the peppered moth story, and in 2000 I included a chapter on peppered moths in my book Icons of Evolution. Then, in 2002, journalist Judith Hooper published a book about the controversy titled Of Moths and Men. Hooper accused Kettlewell of fraud, though I never did; my criticism was directed primarily at textbook writers who ignored problems with the story and continued to use staged photos even after they were known to misrepresent natural conditions.

Jonathan has actually written about a number of  misleading things that you may mind in Biology textbooks.

Here are the sections in his book “Icons of Evolution“:

  • The Miller-Urey Experiment
  • Darwin’s Tree of Life
  • Homology in Vertebrate Limbs
  • Haeckel’s Embroys
  • Archaeopteryx–The Missing Link
  • Peppered Moths
  • Darwin’s Finches
  • Four-Winged Fruit Flies
  • Fossil Horses and Directed Evolution
  • From Ape to Human: The Ultimate Icon

Dr. Wells holds a Ph.D in Molecular and Cell Biology from the University of California at Berkeley.

Were you taught that black and white moths are evidence of evolution?

Here’s a post by Jonathan Wells at Evolution News, which re-caps the history of the peppered moths experiment.

Excerpt: (links removed)

The peppered moth story is familiar — even overly familiar — to most readers of ENV, so I will summarize it only briefly here. Before the industrial revolution, most peppered moths in England were light-colored; but after tree trunks around cities were darkened by pollution, a dark-colored (“melanic”) variety became much more common (a phenomenon known as “industrial melanism”). In the 1950s, British physician Bernard Kettlewell performed some experiments that seemed to show that the proportion of melanic moths had increased because they were better camouflaged on darkened tree trunks and thus less likely to be eaten by predatory birds.

Kettlewell’s evidence soon became the classic textbook demonstration of natural selection in action — commonly illustrated with photos of peppered moths resting on light- and dark-colored tree trunks.

By the 1990s, however, biologists had discovered several discrepancies in the classic story– not the least of which was that peppered moths in the wild do not usually rest on tree trunks. Most of the textbook photos had been staged.

In the 2000s the story began disappearing from the textbooks. British biologist Michael Majerus then did some studies that he felt supported the camouflage-predation explanation. But before he died of cancer in 2009, he only managed to publish a report of his study in the Darwin lobby’s in-house magazine Evolution: Education and Outreach. Now four other British biologists have presented his results posthumously in the Royal Society’s peer-reviewed Biology Letters. In an accompanying supplement, the authors presented their version of what they call “the peppered moth debacle.” And a debacle it certainly is, but not in the way they think.

According to Charles Darwin, natural selection has been “the most important” factor in the descent with modification of all living things from one or a few common ancestors, yet he had no actual evidence for it. All he could offer in The Origin of Species were “one or two imaginary illustrations.” It wasn’t until almost a century later that Kettlewell seemed to provide “Darwin’s missing evidence” by marking and releasing light- and dark-colored moths in polluted and unpolluted woodlands and recovering some of them the next day. Consistent with the camouflage-predation explanation, the proportion of better-camouflaged moths increased between their release and recapture.

Throughout the 1970s and 1980s, however, researchers reported various problems with the camouflage-predation explanation, and in 1998 University of Massachusetts biologist Theodore Sargent and two colleagues published an article in volume 30 of Evolutionary Biology concluding “there is little persuasive evidence, in the form of rigorous and replicated observations and experiments, to support this explanation at the present time.” (p. 318)

The same year, Michael Majerus published a book in which he concluded that evidence gathered in the forty years since Kettlewell’s work showed that “the basic peppered moth story is wrong, inaccurate, or incomplete, with respect to most of the story’s component parts.” (p. 116) In a review of Majerus’s book published in Nature, University of Chicago evolutionary biologist Jerry Coyne wrote: “From time to time, evolutionists re-examine a classic experimental study and find, to their horror, that it is flawed or downright wrong.” According to Coyne, the fact that peppered moths in the wild rarely rest on tree trunks “alone invalidates Kettlewell’s release-and-recapture experiments, as moths were released by placing them directly onto tree trunks.”

In 1999, I published an article in The Scientist summarizing these and other criticisms of the peppered moth story, and in 2000 I included a chapter on peppered moths in my book Icons of Evolution. Then, in 2002, journalist Judith Hooper published a book about the controversy titled Of Moths and Men. Hooper accused Kettlewell of fraud, though I never did; my criticism was directed primarily at textbook writers who ignored problems with the story and continued to use staged photos even after they were known to misrepresent natural conditions.

Jonathan has actually written about a number of  misleading things that you may mind in Biology textbooks.

Here are the sections in his book “Icons of Evolution“:

  • The Miller-Urey Experiment
  • Darwin’s Tree of Life
  • Homology in Vertebrate Limbs
  • Haeckel’s Embroys
  • Archaeopteryx–The Missing Link
  • Peppered Moths
  • Darwin’s Finches
  • Four-Winged Fruit Flies
  • Fossil Horses and Directed Evolution
  • From Ape to Human: The Ultimate Icon

There’s also a documentary based on the book on Youtube.

Dr. Wells holds a Ph.D in Molecular and Cell Biology from the University of California at Berkeley.

Bad news for believers in naturalistic explanations of the Cambrian explosion

Before we see the new discovery, let’s review what the Cambrian explosion is all about.

Video 1:

Video 2:

Casey Luskin explains the new discovery at Evolution News.

Excerpt:

A recent article in Science begins by observing that the lack of evolutionary ancestors for the animal phyla that appear abruptly in the Cambrian explosion has been troubling to many evolutionary scientists:

Ever since Darwin there has been a disturbing void, both paleontological and psychological, at the base of the Phanerozoic eon. If his theory of gradualistic evolution be true, then surely the pre-Phanerozoic oceans must have swarmed with living animals — despite their conspicuous absence from the early fossil record.

(N. J. Butterfield, “Terminal Developments in Ediacaran Embryology,” Science, Vol. 334:1655-1656 (December 23, 2011).)

The articles goes on to explain that in 1998, tiny fossil animal embryos were reported that offered “palpable relief” to those evolutionary scientists worried about the lack of Precambrian ancestors.

However, new analyses of these microfossils now strongly suggest that they were not multicellular animals, and thus could not be Precambrian multicellular metazoa that have long been the holy grail for evolutionary paleontologists. Rather, they likely represent single-celled amoeba-like organisms.

[…]A Science Daily article on the study explains that many Darwinian scientists will be dismayed by the results of this study:

Professor Philip Donoghue said: “We were very surprised by our results — we’ve been convinced for so long that these fossils represented the embryos of the earliest animals — much of what has been written about the fossils for the last ten years is flat wrong. Our colleagues are not going to like the result.”

How did the investigators determine the nature of these ancient organisms? The fossils were exceptionally well preserved, such that, as the lead author on the paper stated, “the fossils are so amazing that even their nuclei have been preserved.” These allowed the authors to determine that these were in fact eukaryotic organisms, but not multicellular animals.

Casey goes on to answer the response by naturalists that “the fossil record is incomplete”.

I think it’s important, when deciding whether naturalistic evolution happened, to be aware of these problem areas. So often when discussing Darwinian evolution, people like journalists and philosophers and economists, etc. will just accept the theory because they trust in what experts tell them. There can be a lot of pressure in the university to not be seen as a dumb person, so that people will just go along with whatever their professor tells them to believe. And, that’s not necessarily a bad policy when time is short. However, that is taking evolution on blind faith. It’s a good thing, as we get older, to go back and revisit these things to see if they are really true.

For example, a really educated Darwinian should be able to finish a sentence like this: “People who doubt fully naturalistic evolution do so because of the following pieces of scientific evidence…” If you meet someone who cannot finish this statement, but who still espouses Darwinian evolution, then you know that you are dealing with someone who has jumped to the answer without really working through the problem by themselves. It can be very tempting, especially for artsy types, to just try to jump to the answer that all the smart people believe without really working through the problem. But that’s not a good way to decide what’s true. Everyone has to work through these problems themselves, and listening to the best people on both sides is the way to do that. People who question evolution nowadays don’t question that the universe is billions of years old or that scientific methods have to be used to answer scientific questions. By all means, let’s decide how we got here by appealing to science.

If you would like to see a nice hour-long video on the Cambrian explosion, then click here.

By the way, if you missed my previous post on the new discovery of oxygen in the early Earth’s environment, and the challenge it represents to naturalistic scenarios for the origin of life, then do check that out.