THE PEPPERED MOTHS

A classic case of variation that is often claimed to be "evolution in action" involves the peppered moth, an insect native to Great Britain. There are two color varieties of this insect. One variety is dark and is camouflaged best against trees with bark that is dark; the dark variety stands out on bark that has light colored lichens growing on it. The other variety is light and is camouflaged best against bark with lichen on it; the light variety stands out on bark that has no lichen growing on it and is therefore dark.

The light variety is more plentiful when light-colored lichens grow plentifully on the tree bark, making the light colored moth invisible to predatory birds. In a similar way, the dark form dominates when lichen growth is scarce and the trees are naturally dark. It is a fact that both light and dark varieties of the peppered moth occur naturally, just as some people have light skin and some people are dark. The genetic code for light or dark coloration has always existed, but the moth population can change color in response to environmental changes that affect the growth of lichen on trees -- and therefore the color -- of the tree bark (see Note 4).

This shift in dominant color with changing environmental conditions is often given as evidence for evolution, but the moth remains a moth, and the population always has the genetic potential for either light or dark coloration. The variation that occurs is simply the expression of the genetic makeup already possessed by the creature. Nothing new or more complex is developing. The shade that predominates is merely the one that is least visible to predatory birds against the prevailing background. This is not evolution. It is simply genetic variation caused by the natural selection exercised by predatory birds on the color they can see and prey on most easily. We see then that natural selection is a real process, but that it always eliminates the most vulnerable individuals; it does not produce anything new, so it is not evolution.

We can now say that while genetic variation is limited, the range of variation in any one kind of life may be large, so large that the population can cope with changing environmental conditions from one generation to another. From a Biblical perspective, genetic variation is the ability for populations to change in response to external pressures. The genetic code that provides the basis for different varieties was programmed into living things by the Creator during the Creation Week. To insure the survival of life, the Creator gave living things the ability to live in, and cope with, changing environmental conditions.

This means that genetic variation is simply the expression of various, but pre-existing, genetic codes. Nothing new is involved in genetic variation, only the expression of already existing characteristics. Thus genetic variation is not evolution. Never has the transformation of one kind of life into another been documented, only the variation of single kinds of organisms within definite, though often surprisingly wide, limits. The evolutionary claim that variation occurs without limit is false. It is a claim without real scientific backing. It is a scientific fallacy of evolution.