Saturday, July 25, 2015

Creation Moment 7/26/2015 - DNA Copying Fidelity

If one had a perfect set-up, the tree of life could have been the provider of the missing nutrient that kept the machine fully functioning in  aperfect state...take it away, and the system breaks down... because only GOD has IMMORTALITY....Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever: Therefore the LORD God sent him forth from the garden of Eden,/..the King of kings,...Who only hath immortality, dwelling in the light which no man can approach unto;
Genesis 3:22,23/1 Timothy 6:15,16


"The Author of life’s solution to the genome
degeneration problem was to provide cells with not just one but a multitude of DNA maintenance and repair mechanisms. Together they ensure a relatively healthy life in the current generation and the prospect of viable offspring for many generations to come.

If such mechanisms had not been present, life would have become extinct very quickly through the multiplication of errors—a condition called ‘error catastrophe’, ....The technical term for maintaining genome quality during reproduction is ‘DNA copying fidelity’ and the enzyme systems that do the copying are called ‘DNA polymerases’.

Copy fidelity maintenance mechanisms include
   proofreading,
   numerous kinds of error correcting systems,
   and error accumulation checkpoints.

According to Thomas Kunkel, a specialist in this field:
DNA copying fidelity is an important area of scientific research … because the balance between correct and incorrect DNA synthesis is relevant to a great deal of biology. High fidelity DNA synthesis is beneficial for maintaining genetic information over many generations and for avoiding mutations that can initiate and promote human diseases … . Low fidelity DNA synthesis is beneficial for generating diversity leading to increased survival of viruses and microbes when subjected to changing environments, and for the development of a normal immune system.
 Copy fidelity varies with the different DNA copying systems used, with the different kinds of errors involved, and with the different stages in a cell’s life cycle. Error rates seem to vary across almost all possibilities, from 1 per nucleotide copied to about 1 in 10–100 million nucleotides, depending on the copy-repair system. Cells also appear to have the ability to combine several diverse copy-repair systems in different ways to achieve cooperatively a greater fidelity than any one system can achieve individually. Overall it appears to be impossible for our cells to copy the 3 billion nucleotides in our genome without error.

A recent study of autozygous DNA in whole genomes of five genealogically well-defined Hutterite parent-offspring trios yielded a single nucleotide mutation rate of 1.2 per hundred million base-pairs per generation. In a genome of 3 billion base-pairs that amounts to 36 single nucleotide changes (SNPs) per person per generation. This figure is smaller than previously measured rates (perhaps because of the investigator’s narrow focus) but will suffice for present purposes. Mutation rates must have varied considerably in the past because a recent study of protein coding genes showed that about 86% of deleterious SNPs have accumulated in the last 200 generations." CMI/AlexWilliams