11 Mart 2008 Salı

How Does My DNA Work?

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 molecular string of chemical information.
DNA is located in the nucleus of our cells and is made up of smaller molecules called nucleic acids. These smaller molecules in DNA are arranged in a sequence, just like the letters in a sentence. The sequence of these nucleic acids tell the cells in our body how to build our nose, eyes, hands, feet, and everything else.
The material our body uses to build new cells 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 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 chemistry and a romance novel!
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. Most biological variations, however, are not from mutations but from new combinations of already existing genes.
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 would 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 new genes for entirely new traits will be produced leading 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 chemistry by accidental changes in the sequence of the letters.
At the very best mutations can only produce new varieties of already existing genes or traits, but not new genes or 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!
No one has shown that DNA can come into existence by chance! It takes DNA to get DNA! Yes, 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.
Science cannot prove the existence of God but the scientific evidence shows that DNA, life, and the universe are not here by chance. For more information on this please read my other articles and, especially, my essay "The Natural Limits of Evolution" at my website www.religionscience.com.
Sincerely, Babu G. Ranganathan (B.A. Bible/Biology)

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