.
Haeckel’s embryos
Darwin thought that “by far the strongest single class of facts” in favor of his theory came from embryology. He relied on German biologist Ernst Haeckel, whose drawings of embryos from various classes of vertebrates showed them to be virtually identical in their earliest stages. They become noticeably different only as they developed. This was the pattern that Darwin found so convincing.
Biologists have known for over a century that vertebrate embryos in fact never do look as similar as Haeckel drew them. It turned out that in some cases, Haeckel simply used the same woodcut for embryos that were then represented as belonging to different classes. In other cases, he doctored his drawings to make the embryos appear more alike than they really were. Haeckel’s own contemporaries were critical of his work, and charges of fraud abounded in his lifetime.
In 1997, British embryologist Michael Richardson and an international team compared Haeckel’s drawings with photographs of actual vertebrate embryos, demonstrating conclusively that the drawings misrepresented the truth. Richardson was quoted in Science: It looks like it’s turning out to be one of the most famous fakes in biology” [9].
Yet some version of Haeckel’s drawings could be found in most current biology textbooks when Wells’ book came out (and possibly still can today). Stephen Jay Gould wrote that we should be “astonished and ashamed by the century of mindless recycling that has led to the persistence of these drawings in large number, if not a majority, of modern textbooks” [10].
Peppered moths
Darwin had no direct evidence of natural selection when he wrote the Origin of Species, so he gave imaginary illustrations. Then, in the 1950s, Bernard Kettlewell seemed to find conclusive evidence of natural selection in Britain. During the previous century, most peppered moths in England had shifted from being light-colored to being dark-colored. It was thought that the dark coloring gave them better camouflage on pollution-darkened tree trunks, protecting the darker moths from predatory birds.
To test this, Kettlewell released light and dark moths onto nearby tree trunks in polluted and unpolluted woodlands, then watched as birds ate the more conspicuous moths. As expected, they caught more light moths in the polluted woodland, and more dark months in the unpolluted one. In Scientific American, Kettlewell called this “Darwin’s missing evidence.” Peppered moths soon became the best example of natural selection in action, and the story was retold in biology textbooks, illustrated by photographs of the moths on tree trunks.
In the 1980s, however, researchers found that peppered moths don’t normally rest on tree trunks. They fly at night and apparently hide under branches during the day. By releasing them onto tree trunks in daylight, Kettlewell had created an artificial situation, and many biologists now consider his results invalid. As for the photos of moths on tree trunks, they were all staged. Photographers even glued dead moths to trees. The people who staged them thought they were representing the true situation, but they were mistaken. Yet they are still used as evidence for natural selection in current biology textbooks [11].
The tree of life
If all living things are gradually modified descendants of one or a few original forms, Darwinism predicts that the history of life should resemble a branching tree. But this has turned out to be wrong in important ways. The fossil record shows the major groups of animals appearing fully formed at about the same time in a “Cambrian explosion,” rather than diverging from a common ancestor. Darwin knew this, and considered it a serious objection to his theory. But he attributed it to the imperfection of the fossil record and believed that future research would supply the missing ancestors.
But almost 150 years of fossil collecting has made the problem worse. Instead of slight differences appearing first, the greatest differences appear right at the start. Some fossil experts note that this “top-down evolution” contradicts the “bottom-up” pattern predicted by Darwin’s theory. Yet most biology textbooks don’t even mention the Cambrian explosion, much less point out the challenge it poses for Darwinian evolution…
“Building blocks”… in a flask
In 1953 it was widely reported that scientists Stanley Miller and Harold Urey had succeeded in creating “the building blocks of life” in a flask. Mimicking what were believed to be the natural conditions of Earth’s early atmosphere, and sending an electric spark through the mixture, Miller and Urey had formed simple amino acids. As they are the “building blocks” of proteins, and proteins are the “building blocks” of life, it was thought that scientists might soon create living organisms.
It appeared to be a dramatic confirmation of evolution. Life wasn’t a “miracle” after all. No outside agent or divine intelligence was necessary. Put the right gases together, add a jolt of electricity, and life was bound to happen. Carl Sagan could confidently predict on television that the planets orbiting those “billions and billions” of stars out there must be teeming with life.
There were problems, however. Scientists were never able to get beyond the simplest amino acids in their simulations, and the creation of proteins began to seem not a small step or a few steps. It involved a great, perhaps impassable divide. An amino acid is to a living organism what a letter of the alphabet is to a Shakespearean play.
Then, in the 1970s, scientists began to believe that the Earth’s early atmosphere was nothing like the mixture of gases used by Miller and Urey. Instead of being a hydrogen-rich environment, it probably consisted of gases released by volcanoes. But put those gases in the Miller-Urey apparatus, and the experiment doesn’t work at all.
Nonetheless, textbooks continue to use the Miller-Urey experiment to argue that scientists have demonstrated an important first step in the origin of life. This includes The Molecular Biology of the Cell, co-authored by the National Academy of Sciences president, Bruce Alberts. They omit to say that the researchers themselves now acknowledge that an understanding of the origin of life still eludes them [13].
[9] Elizabeth Pennisi, “Haeckel’s Embryos: Fraud Rediscovered,” Science, September 5, 1997.
[10] Stephen Jay Gould, “Abscheulich! Atrocious!” Natural History, March 2000.
[11] H. B. Kettlewell, “Darwin’s Missing Evidence,” Scientific American, March 1959; see also Wells, Icons of Evolution, chapter 7.
[13] Wells, Icons of Evolution, chapter 2.
Tom Bethell
“Evolution: The Missing Evidence”
Chapter 14, The Politically Incorrect Guide to Science
