Saturday, April 3, 2010

How Did My DNA Make Me?

by Babu G. Ranganathan

The subject of DNA is very much in the headlines and news but very few have bothered to learn or understand just how this amazing molecule works and how it makes us what we are from head to toe. Haven't you ever asked yourself how you got your nose, eyes, ears, fingers, toes, and everything else? How did your DNA bring all this about? Before we answer that question we need to know just a few simple things about DNA. DNA is the abbreviated name for the genetic code and it is exactly that - a code. It is a sequential molecular string of chemical information.

DNA is located in the nucleus of our cells and is made up of various smaller molecules called nucleic acids. These various smaller molecules in our DNA are arranged in an exact sequence, just like the various letters found in a sentence. The sequence of these nucleic acids tells the cells in our body how to build our nose, eyes, hands, feet, and everything else. If the sequence for something isn't there our bodies won't build it!

The material our body used to build our nose, eyes, ears, brain, and all of our other tissues, organs and structures, and the material our body uses daily to build new cells to replace the ones that are dying comes from the food we eat. Food is not just for energy. Food is also the "lumber" and "bricks" the body uses to build new cells. When a cell multiplies it makes more cells of the same size. The only way to do this is by getting new material and that new material comes from food.

Think about it! When we were in our mother's womb we started off as a single cell not even weighing an ounce at conception. Eventually we developed arms, hands, legs, feet and organs such as brain, heart, lungs, liver, stomach, until we had a complete body. It's true that the single cell we once were multiplied into many more cells, but where did the material come from for that one cell to multiply into billions of more cells of equal size and eventually making a body weighing several pounds from something that didn't even weigh an ounce in the beginning. The material came from our mother's food.

When food is digested and broken down to its basic amino acids the various amino acids are then rearranged in a certain sequence to form cells that make up the various tissues and organs. What sequence these amino acids come together in is determined by the sequence of the molecules in DNA.

Remember, even after all our organs are formed the cells that make up our organs are continually dying and need to be replaced. Again, the material to make more cells to replace the ones that are dying comes from food.

Thus, when you feed your dog a T-bone steak your dog's DNA will make sure that steak is digested and rearranged to form the various parts of your dog, but when you eat the same steak your DNA will make sure that the steak is digested and rearranged to form human parts.

The sequence of molecules in the DNA of a chicken egg turned the food material (egg yolk and whites) of a chicken egg into a cuddly little bird!

Contrary to popular public belief about how evolution is supposed to occur, it doesn't matter what the environment is like. If the genetic information for a certain trait or characteristic is not already in the DNA (or genetic code) of a species then there is nothing in the environment that is capable of putting that information there so that the species would develop that particular trait or characteristic. In other words, it doesn't matter how much a lizard may need to fly in order to be able to survive. If the genetic information for feathers and wings are not in the DNA of a lizard then that lizard will never develop feathers and wings.

The sequence in DNA differs from individual to individual and from species to species. For an analogy, think of a library where all the books are in one language. In the library there are different books on different topics and subjects. All the books share the letters from the same alphabet, but the sequence in which these letters are arranged are different from book to book. The sequence of the letters makes the difference between a book on astronomy and a romance novel!

However, an amazing fact of biology is that every cell in your body, except for your reproductive cells, contains the complete information for the whole body. Yet not all the information in the DNA of your cells is allowed to be expressed or translated. For example, a cell from your hair also contains the complete genetic information for your eyes, brain, heart, liver, skin, and all the rest of the various organs and functions of your body (it's because of this that cloning an entire organism from any cell of the body is possible). However, in the hair cells of your body only the genetic information for your hair is allowed to be expressed, while all the other information is literally "blocked off" from being expressed or translated.

Of course, it is good for us that the cells in our bodies were designed this way; otherwise every cell in our bodies would also be everything else at the same time, which would create utter biological chaos. Truly, we may say with the Psalmist that "we are fearfully (or awesomely) and wonderfully made" (Psalm 139:14). Such biological precision in the cells of our bodies is still beyond the full comprehension of modern science. But the fact remains that the more we comprehend or understand the cell and how it functions, the more we must respect the wisdom behind its engineering and design.

When scientists study genes they are studying segments of the DNA molecule. The goal of the human genome project was to locate where the various genes are on the DNA. Only in this way can we begin to understand how to use genetic engineering to correct various genetically caused disorders and maladies. Faulty genes arise from mutations. Mutations are accidental changes in the sequence of the genetic code caused by radiation and other environmental forces.

Because they are accidents in the genetic code, almost all mutations are harmful. Even if a good mutation does occur for every good one there will be hundreds of harmful ones with the net effect over time being harmful, if not lethal, to the species as a whole.

Evolutionists hope that with enough time and with enough mutations entirely new genes for new traits will be produced which will be preserved by natural selection and which will lead to the evolution of new biological kinds. There is no evidence that this can happen from accidental changes in the sequence of the genetic code, anymore than it's possible to change a romance novel into a book on astronomy by accidentally changing the sequence of the letters.

At the very best mutations can only produce new varieties of already existing traits, but not entirely new traits. For example, mutations in the gene for human hair may change that gene so that another type of human hair develops but the mutations won't change the gene so that feathers or wings develop!

What about “Junk DNA”? The latest science shows that "Junk DNA” isn't junk after all! It's we who were ignorant of how useful these segments of DNA really are. Recent scientific research published in scientific journals such as Nature has revealed that the "non-coding" segments of DNA are more than just useful; they are vital in regulating gene expression (i.e. how, when, and where) genes are expressed.

As for repetitive structures in DNA, they're not junk either. They may have a “back-up” purpose, like a spare tire in car, which the organism can utilize should it lose genetic material due to damage from random mutations caused by environmental forces.

Almost all biological variations are the result of new combinations of already existing genes and not mutations which, as we have seen, are almost always harmful. The very few mutations that are not harmful never produce increasing genetic complexity. Scientists wouldn't expect earthquakes to produce more complex buildings and, yet, scientists who are evolutionists expect random changes (mutations) in the genetic code caused by radiation and/or chemicals in the environment to produce a human being from a fish over millions of years! There simply is no evidence that random or chance mutations in the genetic code can or will ever produce more complex genes leading to more complex biological traits.

It is true that natural selection occurs in nature, but natural selection itself does not design or produce biological variations. Natural selection is an entirely passive process in nature and can work only with biological variations that are possible and which have survival value. Natural selection is simply another way of saying that if a biological variation occurs which is helpful to an animal or plant's survival then that variation will be preserved ("selected") and be passed on. Of course, nature does not do any active or conscious selecting. The term "natural selection" is simply a figure of speech. The important thing to remember is that natural selection can only "select" from biological variations that are possible and which have survival value.

Furthermore, only those mutations produced in the genes of reproductive cells, such as sperm in the male and ovum (or egg cell) in the female, are passed on to offspring. Mutations and any changes produced in other body cells are not transmitted. For example, if a woman were to lose a finger it would not result in her baby being born with a missing finger. Similarly, even if an ape ever learned to walk upright, it could not pass this characteristic on to its descendants. Thus, modern biology has disproved the once-held theory that acquired characteristics from the environment can be transmitted into the genetic code of offspring.

No one has shown that DNA can come into existence by chance! It takes DNA to get DNA! In other words, there must already exist DNA to direct the formation of more DNA. Yes, it is true that the individual molecules that make up DNA have been shown to be able to come into existence by chance. But, it has never been shown that those individual molecules can come together into a sequence by chance to form the genetic code.

Recently, scientists have shown certain molecules coming into existence by chance that can mimic DNA in some respects, but these molecules are not as complex as DNA and they cannot fulfill all of the functions that only DNA and RNA can perform. Showing that these other molecules can come into existence by chance is not the same as showing DNA can come into existence by chance! In fact, as it has already been noted, no scientist anywhere has ever shown that the DNA molecule can originate by chance.

The mathematical odds of the DNA of even the simplest form of life coming into existence by chance is comparable to a monkey typing the sequence of all the letters and words in a dictionary by randomly hitting keys on a computer keyboard or typewriter.

If humans must use intelligence to perform genetic engineering, to meaningfully manipulate the genetic code, then what does that say about the origin of the genetic code itself!

Genetic information, like other forms of information, cannot arise by chance, so it is far more logical to believe that the DNA and biological similarities between species are due to a common Designer rather than common ancestry through evolution by way of random mutations. The Creator simply designed similar functions for similar purposes in all the various forms of life.

DNA similarities within a true species can be used to establish relationship because within a true species the various individuals can interbreed, but this not the case across true species. Therefore, similarities across true species cannot be used for establishing biological relationships. 

Contrary to popular belief, scientists have never created life in the laboratory. What scientists have done is genetically alter or engineer already existing forms of life, and by doing this scientists have been able to produce new forms of life. However, they did not produce these new life forms from non-living matter. Even if scientists ever do produce life from non-living matter it won't be by chance so it still wouldn't help support any theory for the chance or evolutionary origin of life.

In the case involving synthetic (artificial) life, scientists don't actually create or produce life itself from non-living matter. What scientists do in this case is create (by intelligent design) artificial DNA (genetic instructions and code) which is then implanted into an already existing living cell and, thereby, changing that cell into a new form of life. And, again, even if scientists ever do create a whole living cell from scratch (and not just its DNA) it still would not be by chance but by intelligent design. Synthetic life is another form of genetic engineering. But God was there first. Remember that!

What if we should find evidence of life on Mars? Wouldn't that prove evolution? No. It wouldn't be proof that such life had evolved from non-living matter by chance natural processes. And even if we did find evidence of life on Mars it would have most likely have come from our very own planet - Earth! In the Earth's past there was powerful volcanic activity which could have easily spewed dirt-containing microbes into outer space which eventually could have reached Mars. A Newsweek article of September 21, 1998, p.12 mentions exactly this possibility.

"We think there's about 7 million tons of earth soil sitting on Mars", says (evolutionist) Kenneth Nealson. "You have to consider the possibility that if we find life on Mars, it could have come from the Earth" [Weingarten, T., Newsweek, September 21, 1998, p.12]. Furthermore, MIT scientist Dr. Walt Brown (a creationist) in his book In The Beginning points out that during the great Genesis flood, as recorded in the Bible, the fountains of the deep that were let loose could have easily spewed out meteors and meteorites into space that very well may have contained micro-organisms such as bacteria.

If the cell had evolved it would have had to be all at once. A partially evolved cell cannot wait millions of years to become complete because it would be highly unstable and quickly disintegrate in the open environment, especially without the protection of a complete and fully functioning cell membrane.

Of course, once there is a complete and living cell then the biological mechanisms exist to direct the formation of more cells. The question is how did life come about when there was no directing mechanism in Nature. An excellent article to read by scientist and biochemist Dr. Duane T. Gish is "A Few Reasons An Evolutionary Origin of Life Is Impossible" (http://icr.org/article/3140/).

The great British scientist Sir Frederick Hoyle has said that the probability of the sequence of molecules in the simplest cell coming into existence by chance is comparable to the probability of a tornado going through a junk yard of airplane parts and assembling a 747 Jumbo Jet!

Young people, and even adults, often wonder how all the varieties and races of people could come from the same human ancestors. Well, in principle, that's no different than asking how children with different color hair ( i.e. blond, brunette, brown, red) can come from the same parents who both have black hair.

Just as some individuals today carry genes to produce descendants with different color hair and eyes, humanity's first parents, Adam and Eve, possessed genes to produce all the varieties and races of men. You and I today may not carry the genes to produce every variety or race of humans, but Adam and Eve, did possess such genes.

All varieties of humans carry genes for the same basic traits, but not all humans carry every possible variation of those genes. For example, one person may be carrying several variations of the gene for eye color (i.e. brown, green, and blue), but someone else may be carrying only one variation of the gene for eye color (i.e. brown). Thus, both will have different abilities to affect the eye color of their offspring. Our bodies do not express every possible variation of the genes that we carry. One man having black hair may be carrying unexpressed genes for blond hair. Another man having black hair may not be carrying any unexpressed genes for different color hair. There are so many possibilities with genes and their combinations.

Some parents with black hair, for example, are capable of producing children with blond hair, but their blond children (because they inherit only recessive genes) will not have the ability to produce children with black hair unless they mate with someone else who has black hair. If the blond descendants only mate with other blondes then the entire line and population will only be blond even though the original ancestor was black-haired.

What we believe about our origins influences and affects our attitude and philosophy toward life and how we view ourselves (our worth) and how we view others (their worth). This is no small issue!

Yes, natural laws are adequate to explain how the order in life, the universe, and even a microwave oven operates but mere undirected natural laws can never fully explain the origin of such order.

Just because science can explain how life and the universe work doesn't mean there is no ultimate Designer. Would it be rational to believe that there is no designer behind airplanes because science can explain how airplanes work?

We know from the law of entropy in science that the universe does not have the ability to have sustained itself from all eternity. It requires a beginning. But, we also know from science that natural laws could not have brought the universe into being from nothing. The beginning of the universe, therefore, points to a supernatural origin!

Belief in neither evolution nor creation is necessary to the actual study of science itself. One can study and understand how the human body works and become a first class surgeon regardless of whether he or she believes the human body is the result of the chance forces of Nature or of a Supreme Designer.

Science cannot prove that we are here by chance (evolution) or by design (creation). However, the scientific evidence can be used to support one or the other. If some astronauts from Earth discovered figures of persons similar to Mt. Rushmore on an uninhabited planet there would be no way to scientifically prove the carved figures originated by design or by chance processes of erosion. Neither position is science, but scientific arguments may be made to support one or the other.

It is only fair that evidence supporting intelligent design be presented to students alongside of evolutionary theory, especially in public schools, which receive funding from taxpayers, who are on both sides of the issue. Also, no one is being forced to believe in God or adopt a particular religion so there is no true violation of separation of church and state. As a religion and science writer, I encourage all to read my Internet article "The Natural Limits of Evolution" at my website http://www.religionscience.com for a more in-depth study of the issue of origins and intelligent design.

An excellent source of information from highly qualified scientists who are creationists is the Institute for Creation Research (http://www.icr.org) in San Diego, California. Also, the reader may find answers to many difficult questions concerning the Bible (including questions on creation and evolution, Noah's Ark, how dinosaurs fit into the Bible, etc.) at http://www.ChristianAnswers.net.

MIT scientist, creationist, debater, writer, and lecturer, Dr. Walt Brown covers various scientific issues (i.e. fossils, "transitional" links, biological variation and diversity, the origin of life, comparative anatomy and embryology, the issue of vestigial organs, the age of the earth, etc.) at greater depth on his website at http://www.creationscience.com.

Visit the author's new Internet site: THE SCIENCE SUPPORTING CREATION at www.creationismnow.blogspot.com