GENETICS & CREATION

adapted from articles by

David Rosevear

Ph.D., C.Chem.

Used with the kind permission of the Creation Science Movement, 50 Brecon Avenue, Cosham, Portsmouth, England, P06 2AW.

“Like father, like son” is a saying that reflects the observation that offspring resemble - but are not identical to - their parents. The same may be said of plants and animals, which reproduce after their kind without actually cloning themselves. Mendel's experiments in the middle of the nineteenth century showed that the seeds of life contained “factors” (now called genes) controlling the expression of biological characteristics.

Chemicals and Information

Today we know that genetic information is carried on the nucleic acid molecule known as DNA (DeoxyriboNucleic Acid): a string of nucleotides, each composed of a sugar, a phosphate group, and a base. The nucleotides of DNA differ only in their bases, which can be one of four different molecules. The DNA string of genetic information is rather like a sequence of dots and dashes in a Morse code message. It carries the encoded instructions of how to construct a particular organism. DNA molecules consist of nucleotide pairs numbering anywhere from a few thousand to many millions, arranged on double strands that complement one another.

The sequence of DNA nucleotides codes for the organization of a amino acids that make up proteins. Three adjacent nucleotides (a codon) specify a particular amino acid. Most of the 20 amino acids found in proteins can be specified by more than one sequence of three nucleotides. (There are 64 ways of arranging the four different nucleotides into groups of three - 4³.) The typical protein consists of over 100 amino acids.

To manufacture a protein, first a template of the relevant portion of coded information on a strand of DNA is made. This results in a strand of nucleic acid known as mRNA (messenger RiboNucleic Acid). The enzymes carrying out the operation ensure that the correct section of DNA is transcribed into mRNA by reading special initiator and terminator nucleotide sequences on the DNA strand. The mRNA template will then be used to assemble a particular sequence of amino acids that will go into building a specific protein.

The length of DNA that expresses a single biological characteristic is found in the gene. Many genes are packed together into chromosomes. A given gene may be involved in the expression of more than one characteristic, and more than one gene may be needed for the expression of a single characteristic; for instance, two genes code for eye color in man.

Humans have 46 chromosomes arranged and 23 pairs. All of the cells in the human body have these 46 chromosomes, except sperm and egg cells, which have only 23. A fertilized egg inherits a complement of 46 chromosomes by combining 23 chromosomes from each parent. Because of the blend of parental genes, there will be a unique expression of characteristics in the offspring. The DNA code for man consists of about three thousand million (i.e., three billion) nucleotide pairs.

The variation produced in offspring by combining parental genes cannot produce anything truly novel, any more than the shuffling of a pack of cards can produce an eleven of hearts. Variations within a kind - often referred to misleadingly as “micro-evolution” - should not be taken to be evidence of evolution. A popular case in point is the speckled moth, Biston betularia.

Apparent changes in the melanism of the speckled moth population due to changes in the environment have nothing to do with evolution. From start to finish, the population consisted of both light and dark forms of this species of moth, and they were never anything other than Biston betularia.

Do Genes Evolve by Mutations?

When cells divide to reproduce, there is a high degree of fidelity in the duplication of genetic information. During the replication process, 100 nucleotides are manufactured every second. (It takes a trained chemist with sophisticated apparatus days to make just one.) It is estimated that mistakes in copying occur in only 1 out of 100,000 million (i.e. 100 billion) nucleotides. But even then, there are enzymes that repair incorrect or damaged nucleotides in order to prevent genetic changes in the species.

The party game in which a whispered message is passed round the room from person-to-person demonstrates that copying errors do indeed corrupt information. When genetic changes manifest in nature - due to the effects of mutagenic chemicals, radiation, or unrectified mistakes in copying - the resulting mutant gene is usually incapable of functioning. Most mutations are harmful or lethal to organisms, for the same reason a mistake in a precision-engineered machine will damage its performance and render its output worthless. No truly beneficial mutation has ever been recorded.

Some point to the fact that the mutation responsible for sickle-cell anaemia renders its carrier immune to malaria as evidence of a beneficial mutation. But this is not due to any improvement in the blood cell in an evolutionary sense. Rather, it stems from the fact that the life-span of the defective blood cell is shorter than the incubation period of malarial protozoa. In regions where malaria is a common cause of death, sickle-cell anaemia carriers do have a comparative advantage, and a higher proportion of the population carries the mutant gene than in regions where malaria is not a threat. But sickle-cell anaemia can be lethal. When the defective gene is inherited from both parents, the sufferer usually dies before reaching adulthood.

Chromosomal mutations are known to occur, but they are rare. They can involve the loss or the duplication of a segment in a chromosome. Occasionally, a segment of a chromosome may be reversed, causing the nucleotides to be in the wrong order. Translocation errors are another kind of mutation. They happen when the position of a segment within a chromosome is changed; segments on different chromosomes may even be exchanged. Could these mistakes, rare as they are, be a mechanism for evolution?

The segments of genetic information riding on chromosomes are analogous to the text printed on the pages of a book. From time to time in the production of a book, at the typesetting stage, a mistake is made - a “mutation,” if you will. Usually the mistake is noted and rectified by the proofreader - the “reparative enzyme” of publishing. If the mistake escapes detection and correction, it leads to a loss of information. At the binding stage of book production, occasionally some of the pages are inadvertently bound in the wrong order, inserted upside-down, left out, or duplicated in the same volume. These are the “chromosomal mutations.”

Any one of these mistakes renders a book less functional as a carrier of information. No new information is introduced by such errors. The book does not evolve from fiction into non-fiction or from a primary reader into a university textbook!

Since random changes in genetic information are deleterious, mutations can hardly be for the modus operandi of evolutionary progress.

Transfer of Genes between Bacteria

It has been found that the DNA segments called episomes may be transferred from one bacterial cell to another, becoming incorporated into the genetic make-up of the host cell. These episomes contain genes that build bridges between bacterial cells in order to effect transfers of genetic information. They may also possess genes that give the invaded bacterial cell an ability to resist certain antibiotics. Might this mechanism for increasing cellular genetic information be regarded as a candidate for evolutionary change?

Two points should be noted in this regard. Bacteria differ from the cells of all plants and animals in that they have no membrane surrounding their genetic material, and the bacterial cell has no nucleus. The invasion of foreign DNA into eukaryotic cells (cells containing a nucleus) has not been seen outside of the genetic engineering laboratory. The other point of note is that the episome appears to be purpose-built for invading other bacterial cells and implanting information in them. Episomes cannot, by virtue of their information content, arise by chance. This mechanism is clearly part of the design of these life forms. Unless the episome were perfectly formed, it could not operate. The episome performs a carefully designed operation to impart genetic information. As such, it qualifies more as evidence in support of creation than data buttressing the theory of evolution.

Natural Selection

It has been claimed that natural selection plays a part in the alleged evolution of life forms because mutants that are better suited to environmental change are favourably selected. However, since the effects of mutations upon the viability of organisms range from the inconsequential to the catastrophic, mutants are far more likely to be weeded out by natural selection than helped by it. When a mutant gene is inherited from only one parent, the non-mutant allele will probably be expressed, but if the mutant gene is inherited from both parents, there is a loss of “fitness.” In reality, natural selection serves to conserve genetic information and the status quo: it is not a means of evolving kinds of life that are more “fit” than their predecessors.

Common Genetic Code

A given sequence of three nucleotides virtually always codes for the same amino acid, whether it occurs in a spider, an elephant, or a human being. According to some geneticists, this is evidence for evolution. If all organisms had evolved from an original single cell, so the argument goes, one might expect to see a common genetic code in all living organisms.

But equally so, the universal genetic code for each amino acid provides evidence for creation: If all life forms had been created by a Designer, one would expect to find a common code for gene translation.

Genetic Information

In the same way the message conveyed by the sequence of dots and dashes of a telegraph message is decoded according to formulas prescribed by Samuel Morse, so the sequence of nucleotides in protein synthesis is interpreted by the genetic code. In other words, in addition to the physical substances of nucleotides and amino acids, there needs to be an intelligent interpretation of their arrangement using decoding information.

In order for an organism to evolve, new genetic information must be added to the DNA. But according to information theory, an input from an intelligence source is needed to create information. Just as a computer program requires an intelligent designer, so the far more complex information processing system that governs genetic reproduction requires an intelligent Source. The information content of genetic material simply could not have arisen by the natural selection of random changes.

The very existence of complex genetic information is strong evidence that living things were created.

Mitochondrial Genes

Lying outside the nucleus, the mitochondria of a cell are involved in the production of energy from food using cytochrome-c. They have small amounts of nucleic acid, which in man contains just 16,569 nucleotide pairs. Mitochondrial DNA in humans is inherited only from the mother. Comparisons of the mitochondrial DNA in people of different races throughout the world have convinced some geneticists that everyone can trace their ancestry back to a single female, Eve, the mother of all living. The vast majority of human mitochondrial DNA is identical, but mutations do occasionally occur. Estimates of the rate of mutation in mitochondrial DNA suggests to scientists that our first mother lived some 200,000 years ago. Of course, the date is accurate only to the extent that the estimated mutation rate is correct. Nonetheless, the estimate for the age of man stands in marked contrast to the million or more years proffered by palaeontologists trying to reconstruct man's evolution from questionable fossil fragments.

It is interesting to note that studies of the genes of human beings show that variation among individuals and different ethnic groups is no greater than the variation found within any one group. The study of genetics does not support the idea that the races evolved separately, as Darwin thought; rather, it suggests that we all came from one set of parents.

Conclusion

As research reveals more and more about the ways in which characteristics are inherited from generation to generation, we find that the facts tend to support special creation theory and undermine the theory of evolution.

Studies of genetic variation suggest that all mankind shares a common ancestor who lived in the recent past. Natural selection works to conserve the genetic status quo by eliminating mutants. Mutations lead to a loss of information, and rearranging the genes cannot produce new information. Proteins and the process by which they are manufactured by DNA are incredibly complex, and the information riding on these chemicals is immense. All of this is evidence for a supremely intelligent Designer of life, not a developmental process based on chance mutations.