The sole example of a "useful mutation" that evolutionist biologists refer to is the disease sickle cell anemia, in which the hemoglobin molecule responsible for transporting oxygen becomes deformed and changes shape. As a result, its ability to transport oxygen is seriously impaired.
Victims of sickle cell anemia suffer increasing respiratory difficulties. Yet this example of mutation, discussed under blood diseases in medical textbooks, is regarded as advantageous by some evolutionist biologists.
Sufferers from this disease enjoy a partial immunity to malaria, and this is described as an evolutionary adaptation. Using that kind of inconsistent logic, one could say that the genetically lame were spared being killed in traffic accidents since they could not walk, and that lameness is a useful genetic trait..
It is clear that mutations have only destructive effects. Pierre Paul Grassé, former president of the French Academy of Sciences, compares mutations to spelling mistakes during the copying of a written text. Like spelling mistakes, mutations add no further information, but rather damage what is already there. Grassé goes on to say:
Mutations, in time, occur incoherently. They are not complementary to one another, nor are they cumulative in successive generations toward a given direction. They modify what preexists, but they do so in disorder, no matter how . . As soon as some disorder, even slight, appears in an organized being, sickness, then death follow. There is no possible compromise between the phenomenon of life and anarchy [disorder]. 225
225. Pierre-Paul Grassé, Evolution of Living Organisms, New York: Academic Press, 1977, pp. 97-98.