Wednesday, October 19, 2022

Creation Moment 10/20/2022 - The Fabled "Peppered Moths"

The heart is deceitful above all things, and desperately wicked: who can know it?
Jeremiah 17:9
 
"The peppered moths of southern England might be the most famous, and yet the most fraudulent “icon of evolution.” The story has been ubiquitous.

peppered moths come in light and dark shades. In the early nineteenth century, most of the moths were of the lighter shade, but over the course of the century, as industrial pollution worsened, the moth population became predominantly dark colored. In the 1950s, a researcher named Bernard Kettlewell conducted a famous study of the peppered moths in which he released moths onto tree trunks and observed predatory birds picking them off. Kettlewell noticed that pollution had killed the light-colored lichens on tree trunks; he concluded that the lighter moths were too conspicuous against the darker tree trunks. As a result of their camouflage advantage on the darker tree trunks, the dark moths flourished and came to predominate. 
 
peppered moths have been the favorite textbook example of natural selection for over forty years. Usually, the text is accompanied by pictures of moths on tree trunks, illustrating how the lighter colored moths are almost invisible against the lichen-covered trunk but dangerously exposed on the dark tree trunk devoid of lichens.
Great illustration of evolution in action . . . except that the photographs were staged. Dead moths were glued or pinned onto tree trunks before the pictures were snapped. Sometimes photographers placed live peppered moths, which are torpid in daylight, on the tree trunks. This would have been a legitimate illustrative technique if peppered moths typically lighted on tree trunks, but scientists now know that they usually do not. 
 
First, a series of experiments showed that there was no correlation
between lichens and the distribution of light and dark colored moths. Then, a series of experiments demonstrated that most of the time,
peppered moths rest in the canopies of trees, usually on the underside of horizontal branches.
The later experiments seem to show a correlation between industrial pollution and moth melanism, but Kettlewell’s theory about lichens, camouflage, and selective predation by birds—the part of the story used to illustrate natural selection—has been debunked. Although scientists have known since the 1980s that peppered moths do not normally rest on tree trunks and that the photographs of moths on tree trunks did not reflect reality, the illustrations keep showing up in textbooks." David Read//F7