The Complexity of the Genetic Code

Human cells (except for red blood cells) contain in their nuclei pairs of chromosomes (number 1 through 22 plus X and Y sex-determining chromosomes). Half of these 46 chromosomes are inherited from one's father, and half from the mother. The female ovum always contributes an X sex-determining chromosome, whereas the male sperm contributes either an X or a Y sex chromosome determining the sex of the child---whether it will be a boy (XY) or a girl (XX), respectively. This amazing genetic code---arranged to form the double-helix of DNA---governs not only the transmission of thousands of characteristics of life from one generation to another, but also oversees countless biological and chemical interactions of living cells on a moment by moment basis.

There are on average 30,000 genes per chromosome. The longest chromosomes contain 300 million bases. The genetic alphabet out of which genes are composed consists of four "letters," or bases. Each of these nucleic acid bases must be joined to its neighbors in precisely the correct order! Prof. A. E. Wilder Smith notes that the arrangement of bases is three-dimensional---an equivalent amount of information packed into two dimensions would make the length of the genome many thousands of miles long! Individual genes govern skin color, eye color, a multitude of other physical characteristics, and a good many less tangible factors such as intelligence level and temperament as well.

The complete total of chromosomes which constitutes the human "genome" consists of at least 3.5 billion bases. In 1986 The National Academy of Sciences began the ambitious process of decoding the human genome---expected to take about 2 years and three billion dollars. Time magazine for the week of February 8, 1993, however reported an accelerated program by a team of scientists in France who expect to get the job done two years before the Americans. [A Nova Science television program on the human genome program had the fascinating title, The Book of Life, perhaps suggesting the record books that God keeps as described in Bible passages such as Revelation 20:11-14].

The genetic codes in all living things represents an enormous degree of complexity. Chromosomes are made up of NUCLEIC ACIDS (not amino acids). Nucleotides are made up of three components: a heterocyclic nitrogenous base (adenine, thymine, cytosine, or guanine) a pentose (a sugar), and a phosphoryl group. The bases themselves do not link together to form the
double helix -- the pentose-phosphate portion of the molecules form phosphodiester bonds (not peptide bonds) to form the backbone of the double helix.Nucleotides (unlike amino acids) do not have right and left-handed configurations, per se. But the double helix can form in either a right or left-handed direction. Most DNA is in the right-handed double helix form, although there are certain unusual situations in which the left-handed double helix is used. Nucleotides are joined by phosphodiester bonds (not peptide bonds). Peptide bonds occur only between amino acids, primarily in the formation of proteins. DNA is not a protein. It is true that multiple special enzymes are required. I find this part of DNA formation fascinating. Some enzymes actually have a proof-reading function, double checking to make sure that not mistakes in
transription are made. As far as I know, most mistakes (mutations) are random in the sense that an unusual nucleic acid ends up in the wrong place and is not caught by the proof-reading enzymes. This only happens about once every several million base pairs, and is usually taken care of enzymes which recheck DNA post-replication." (1)

According to Genesis, God created various kinds (Heb: min) of living things from simple grasses to man. Each kind contains its own unique genetic program code (seed) allowing the parent organism(s) to replicate either sexually or asexually. Evidently these genetic codes were written by our Creator with a redundant amount of information in them---providing all the information needed for a wide variety in the offspring and also permitting a considerable amount of modification and adaptation within each kind. The term kind used in Genesis is not necessarily synonymous with the secular scientific term species, however it is clear that one kind of life does not interbreed with another kind. Mutations (caused by cosmic rays for instance) cause damage to genes in the chromosome, but these are always disadvantageous to the individual and represent errors in the genetic codes.

Tremendous variation is possible within kinds. To give just one simple example, the table below shows all the possible combinations of the skin-color pigment melanin starting with two medium-skinned parents, AaBb. Only 6 out of 16 possible combinations leading to medium skin color will occur. The combination AABB produces only dark skin, aaBB produces only medium skin and aabb only light skin. Four each of their children can be expected to have either dark or light skin. All these possible combinations could occur in only one generation! It follows that Adam and Eve were created with the complete gene pool now found in all human beings who have ever lived or who are alive today, or yet to be born!

A narrowing of the genetic funnel would have occurred at the time of the Flood a few thousand years ago. The Biblical view is that all current members of the human race on earth are descendants of Noah and his wife. There is therefore but one "race" of men on earth. An immediate genetic diversification then set in, in the rapid repopulation of the earth through Noah's three sons, Shem, Ham, and Japheth. (See Genesis 10, 11).

An excellent introduction to the central question of biological origins is the book Of Pandas and People, by Percival Davis and Dean H. Kenyon, Haughton Publishing Co., Dallas, TX 1989. An easy to understand book presenting evidence for creation and refutation of the many of the arguments of the myth of evolution is Creation: Facts of Life by Gary Parker, Master Books, PO Box 26060 Colorado Springs, CO 80936, 1994.

In The Mystery of Life's Origin: Reassessing Current Theories, Charles Thaxton, Walter Bradley and Roger Olsen (Philosophical Library, NY 1984) calculate the energy and entropy levels involved in assembling the complex molecules that comprise the genetic code. From their work it is clear that the complex genetic program each of us inherited was created by a Superior Intelligence at the beginning-it could not possibly have "evolved." The Second Law of Thermodynamics demands that orderly, complex systems break down, fall apart, rot, rust and decay with the passage of time. Outside energy and outside Intelligence were required to bring the genetic code into existence.

The God of the Bible brings:

matter out of nothing,
order out of chaos,
light out of darkness,
and life out of death.

Related material:

• Creation, Mutation, and Variation, by Gary E. Parker
  
• Ray C. Stedman on Genesis
  
• World Population Since Creation
  
• The Table of Nations

Recent News:

Daughters of Eve

Geneticist: All Europeans Descended From Seven Matriarchal Clans
An English geneticist says he has found that Europeans are descended from seven matriarchal groups, based on his analysis of mitochondrial DNA. Check out our map to see his description of the leaders of each "clan." (PhotoDisc)

By Jennifer Viegas Special to ABCNEWS.com

April 21 - It may be the world's largest known family tree.

Researchers from Oxford University in Oxford, England, have identified seven ancestral matriarchal groups from which all Europeans appear to be descended. These maternal clans form the root of a family tree that has sprouted millions of individuals.

Every European, according to the study, can trace his or her evolutionary history back to the seven ancestral mother groups, also referred to as the Seven Daughters of Eve.

The researchers, who both discovered and formulated the genetic groupings, say these women would have lived between 8,000 to 45,000 years ago.

Hamsters Inspired Theory

Bryan Sykes, professor of human genetics at Oxford University, first suspected Europeans could have common lineages when he was a young boy. His inspiration came from a news story he read that stated all hamsters in the world came from one pregnant female found in the Syrian desert in 1930.

Time passed, but he remembered the hamsters. In recent years, he tested out the hamster idea by identifying and ordering the individual components of DNA taken from the droppings of several of these rodents.

He discovered that one specific kind of genetic material, mitochondrial DNA, appeared to be identical among all of the hamsters. This kind of DNA can only be passed down from a mother to her children.

Men have mtDNA in their sperm, but a chemical marks it for destruction during the fertilization process. Therefore, the hamster study findings prompted Sykes to add matriarchal clans to his developing theory about common lineages.

A Cheeky Business

Then, Sykes applied similar research methods to a study on humans. He and his colleagues took cell samples from the cheeks of 6,000 Europeans and analyzed their mitrochondrial DNA.
Unlike hamsters, which share one type of mtDNA, the human test subjects' DNA clearly fit into seven distinct groups: the seven daughters on the European family tree. The "daughters" notion is more figurative than literal, as it broadly refers to seven matriarchal genetic groups, rather than to seven individual women.

Leonardo Salviati, a post doctoral researcher at Columbia University who specializes in mitochondrial DNA studies, says Sykes' theory "is plausible."

"Mitochondrial DNA allows us to trace human evolution," says Salviati. "DNA mutates at a very slow rate, so if you can accumulate mutations and categorize them in specific groups, you can draw direct ancestral lineages."

Mutations in this kind of DNA occur in humans about every 10,000 years. Sykes, therefore, is able to guess when each of the seven female genetic lines first appeared in Europe.

The earliest suspected arrival date, 45,000 years ago, corresponds with the appearance of modern human remains in fossil records. But this date is thousands of years ahead of when anthropologists previously thought migrants arrived in Europe.

Links to African Eve

Further, all seven of the genetic groups appear to be descended from the "Lara" clan, one of three clans that still exist today in Africa. This supports the African Eve theory, proposed in the late '80s by biochemist Allan Wilson, Mark Stoneking and others, which states that all humans share a common African ancestor. Wilson and his colleagues used the same genetic material, mtDNA, for their study.

Terry Melton, president of Mitotyping Technologies, a firm specializing in mtDNA forensic studies, says, "[Sykes] presents a great idea, but the system is not perfect. A consensus may be derived by formulating haplogroups [gene groups], but it would be impossible to do this with 100 percent accuracy."

Melton explains that some parts of the mtDNA mutate faster than others, so additional variation could appear within the seven daughter groups.

What About Americans?

Americans of European heritage may fit into one of the seven categories. But different genetic groups based upon mtDNA variations likely exist for those without European ancestors.
Native Americans, for example, appear to have descended from Asians who migrated to the Americas sometime between 30,000 and 3000 BC. Melton says they seem to have limited mtDNA variations, meaning that they probably descended from just a few Asian lineages.
In future, Sykes hopes to map out genetic groups for other continents, to perhaps find out more about the mothers to us all.

The Seven Daughters of Eve

Professor Sykes and his team have created profiles for each of the seven matriarchal groups. They are:

Helena - This clan lived in the ice-capped Pyrenees. As the climate warmed, Helena's descendants trekked northward to what is now England, some 12,000 years ago. Members of this group are now present in all European countries.

Jasmine - Her people had a relatively happy life in Syria, where they farmed wheat and raised domestic animals. Jasmine's descendants traveled throughout Europe, spreading their agricultural innovations with them.

Katrine - Members of this group lived in Venice 10,000 years ago. Today most of Katrine's clan lives in the Alps.

Tara - Sykes' maternal ancestry goes back to this group, which settled in Tuscany 17,000 years ago. Descendants ventured across northern Europe and eventually crossed the English Channel.
Ursula - Users of stone tools, Ursula's clan members drifted across all of Europe.

Valda - Originally from Spain, Valda and her immediate descendants lived 17,000 years ago. Later relatives moved into northern Finland and Norway.

Xenia - Not much is known about Xenia, but it is believed that her people lived in the Caucasus Mountains 25,000 years ago. Just before the Ice Age, this clan spread across Europe, and even reached the Americas.

Oxford Ancestors, a venture associated with Oxford University, will trace individual matrilineal DNA, for a fee of $180 per test (see link).

http://www.nytimes.com/library/national/science/050900sci-genetics-jews.html

With a new technique based on the male, or Y, chromosome, biologists have traced the diaspora of Jewish populations from the dispersals that began in 586 BC to the modern communities of Europe and the Middle East.

The analysis provides genetic witness that these communities have, to a remarkable extent, retained their biological identity separate from their host populations, evidence of relatively little intermarriage or conversion into Judaism through the centuries.

Another finding, paradoxical but unsurprising, is that by the yardstick of the Y chromosome, the world's Jewish communities closely resemble not only one another but also Palestinians, Syrians and Lebanese, suggesting that all are descended from a common ancestral population that inhabited the Middle East about 4,000 years ago.

Lawrence H. Schiffman, chairman of the department of Hebrew and Judaic Studies at New York University, said the study fit with historical evidence that Jews originated in the Near East and with biblical evidence suggesting that there were a variety of families and types in the original population. He said the finding would cause ``a lot of discussion of the relationship of scientific evidence to the manner in which we evaluate long-held academic and personal religious positions,'' like the question of who is a Jew.

The study, reported in today's Proceedings of the National Academy of Sciences, was conducted by Dr. Michael Hammer of the University of Arizona with colleagues in the United States, Italy, Israel, England and South Africa. The results accord with Jewish history and tradition and contradict theories such as those holding that Jewish communities consist mostly of converts from other faiths or that they are descended from the Khazars, a medieval Turkish tribe that adopted Judaism.

The analysis by Hammer and his colleagues is based on the Y chromosome, which is passed unchanged from father to son. Early in human evolution, all but one of the Y chromosomes were lost as their owners had no children or only daughters, so that all Y chromosomes today are descended from that of a single genetic Adam who is estimated to have lived about 140,000 years ago.

In principle, all men should therefore carry the identical sequence of DNA letters on their Y chromosomes, but in fact occasional misspellings have occurred, and because each misspelling is then repeated in subsequent generations, the branching lineages of errors form a family tree rooted in the original Adam.

These variant spellings are in DNA that is not involved in the genes and therefore has no effect on the body. But the type and abundance of the lineages in each population serve as genetic signature by which to compare different populations.

Based on these variations, Hammer identified 19 variations in the Y chromosome family tree. The ancestral Middle East population from which both Arabs and Jews are descended was a mixture of men from eight of these lineages.

Among major contributors to the ancestral Arab-Jewish population were men who carried what Hammer calls the ``Med'' lineage. This Y chromosome is found throughout the Mediterranean and in Europe and may have been spread by the Neolithic inventors of agriculture or perhaps by the voyages of sea-going people such as the Phoenicians.

Another lineage common in the ancestral Arab-Jewish gene pool is found among today's Ethiopians and may have reached the Middle East by men who traveled down the Nile. But present-day Ethiopian Jews lack some of the other lineages found in Jewish communities, and overall are more like non-Jewish Ethiopians than other Jewish populations, at least in terms of their Y chromosome lineage pattern.

The ancestral pattern of lineages is recognizable in today's Arab and Jewish populations, but is distinct from that of European populations and both groups differ widely from sub-Saharan Africans.

Each Arab and Jewish community has its own flavor of the ancestral pattern, reflecting their different genetic histories. Roman Jews have a pattern quite similar to that of Ashkenazis, the Jewish community of Eastern Europe. Hammer said the finding accorded with the hypothesis that Roman Jews were the ancestors of the Ashkenazis.

Despite the Ashkenazi Jews' long residence in Europe, their Y signature has remained distinct from that of non-Jewish Europeans.

On the assumption that there have been 80 generations since the founding of the Ashkenazi population, Hammer and his colleagues calculate that the rate of genetic admixture with Europeans has been less than a half-percent per generation.

Jewish law tracing back almost 2,000 years states that Jewish affiliation is determined by maternal ancestry, so the Y chromosome study addresses the question of how much non-Jewish men may have contributed to Jewish genetic diversity. Hammer was surprised to find how little that contribution was. ``It could be that wherever Jews were, they were very much isolated,'' he said.

Psalm 139