Sickle Cell Anemia and Other “Good” Mutations of Evolution

by Dr. David Menton on August 12, 2017; last featured February 24, 2024

Editor’s Note: First published in St. Louis MetroVoice 4, no. 3 (March 1994).

The marvelous ability of all living things to reproduce themselves after their kind is one of the most distinctive properties of life. This reproductive ability depends in part on a vast collection of precise genetic instructions called genes (about 25,000 in humans) that reside in every cell of each living organism. It is believed that these genes provide the instructions necessary for not only the assembly and function of each cell, but also for all the organs and even the entire body! A complete set of these instructions is stored in the chromosomes, inside the nucleus of the cell.

The survival of every living species depends on its ability to pass on its precious genetic instructions, from generation to generation, without significant alteration. First, all of the genetic instructions must be precisely duplicated and passed on by the germ cells to enable the birth of each new individual. Then, from the very first cell of a new individual (a fertilized egg), the genetic instructions must be accurately duplicated for the subsequent production of every cell that makes up the whole organism—about 70 trillion cells (of several hundred different kinds) in the case of our own body! This process must continue throughout life in order to support growth and repair, as well as to replace cells that are continually dying. The red blood cells of our body, for example, are being produced at the rate of about two million per second, to replace older cells, which are dying at the same rate!

If a species is to survive, the frequent duplication of its genetic instructions must occur with great precision.

If a species is to survive, the frequent duplication of its genetic instructions must occur with great precision. There are, in fact, several error-checking mechanisms in living cells that help to ensure the accuracy of their gene duplication. But even if copy errors are avoided, errors can still occur when the cell is not dividing or reproducing. We call such errors that creep into the genetic instructions of a cell mutations. There are several kinds of chemicals, viruses, and radiations that are known to cause mutations. Ultraviolet light from the sun, for example, can cause mutations in our skin, resulting in a benign form of skin cancer called basal cell carcinoma. Cancer is so closely associated with mutations that the terms carcinogenic (cancer-causing) and mutagenic (mutation-causing) are essentially synonymous. Nonetheless, evolutionists insist that some mutations are beneficial and lead to the gradual improvement of a species!

Chance mutations amount to random changes in the highly complex and integrated genetic instructions of the cell. Such changes would be no more likely to improve a living cell (or organism) than would a random interchange of connections in a television set be likely to improve the picture. Although some mutations have no noticeable effect, many are harmful and even fatal. Mutations are so harmful, in fact, that the very survival of all living organisms (from bacteria to man) depends on a complex biochemical mechanism in each cell that identifies mutations as they occur—and repairs them! This marvelous mutation repair mechanism involves an integrated sequence of special enzymes that actually cut out the erroneous (mutant) parts of each gene, and then splice in correct patches. The whole field of “genetic engineering” is based on the discovery, and use, of these naturally occurring “cutting” and “splicing” enzymes.

The importance of mutation repair to human life can be appreciated by examining what happens when it doesn’t work properly. There is a human disease called xeroderma pigmentosum, which results from a single defect (itself a mutation) in the complex mutation repair process. This is a hereditary disease in which the skin and other tissues react in a hypersensitive way to any form of radiant energy. When people suffering from this disorder are exposed to sunlight or x-rays, for example, they develop progressive degenerative changes (more mutations), which lead to cancer, including the often fatal malignant melanoma.

Regrettably, some mutations manage to escape even the normally functioning repair process, and these accumulate throughout life.

Some scientists have proposed that aging and death are the result of such unrepaired mutations. It is hard to imagine that anyone could find something good to say about unrepaired mutations—except evolutionists. Evolutionists, you see, believe that mutations (and indeed death itself) are absolutely essential for the chance evolution of all living organisms, including man. The reason for this, as evolutionist Theodosius Dobzhansky points out, is that “the process of mutation is the only known source of the new materials of genetic variability, and hence evolution” (American Scientist 45:385). Thus, evolutionist Carl Sagan could say in his book, The Cosmic Connection, “We (humans) are the products of a long series of biological accidents.”

Are there any known examples of unquestionably “beneficial” mutations?

Are biological accidents (mutations) up to the task that evolutionists claim for them? Are there any known examples of unquestionably “beneficial” mutations? Ironically, the primary textbook example of a “good” mutation is one that causes the disease sickle cell anemia. This mutation of blood hemoglobin is considered “good” because people who have it (and survive it) are more resistant to the disease malaria. The symptoms of this “good” mutation include acute attacks of abdominal and joint pain, ulcers on the legs, defective red blood cells, and severe anemia—often leading to death. One can only imagine what the “bad” mutations are like! No wonder that H. J. Mueller, who won the Nobel Prize for his work on mutations, said:

It is entirely in line with the accidental nature of mutations that extensive tests have agreed in showing the vast majority of them detrimental to the organism in its job of surviving and reproducing— good ones are so rare we can consider them all bad (Bulletin of the Atomic Scientists 11:331).

The unquestioning faith of evolutionists in the occurrence and beneficial effects of “good” mutations is sustained despite overwhelming evidence against it. In his book Genetics and the Origin of Species, Dobzhansky admits that mutations arising both in the laboratory and in natural populations typically produce deterioration, disease, and monstrosities. He even concedes that “such changes it would seem, can hardly serve as evolutionary building blocks.” Yet in his book Mankind Evolving, Dobzhansky insists, “This is not inconsistent with the recognition that useful mutations did occur in the evolutionary line which produced man, for otherwise obviously, mankind would not be here.” Such childlike and unquestioning faith is not found in all of Christendom. Think about it: chance mutations or intelligent design—which explanation of the origin of the incredible integrated complexity of life requires the greater faith?

Essays on Origins: Creation vs. Evolution

The Missouri Association for Creation ( and Dr. Menton have graciously granted AiG permission to publish this book online. To purchase a copy please visit our online store.


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