25 Years of Study on DNA Copy and Repair Mechanisms Summarized 07/18/2001
The July 17 issue of the Proceedings of the National Academy of Sciences contains a long paper by two MIT biochemists on what we have learned so far in 25 years of study of enzymes that help copy and repair DNA: the DNA polymerases. Apparently these wonder molecules not only synthesize DNA but repair a number of different kinds of errors. The coordination of which polymerase is activated and tosses the baton to another is still poorly understood. Most of the work has been done on E. coli, a prokaryote (simpler one-celled organisms lacking a nucleus), but the situation is even more complex in the eukaryotes (all higher organisms), “where both the number of DNA polymerases and the level of complexity of the events are far greater.”
If your brain can tolerate the technical jargon without crashing, and if you need evidence for a Designer, you should read this paper. The authors seem truly amazed at the performance of these submicroscopic molecules. Some sample sentences:
• A common, defining feature of these DNA polymerases is a remarkable ability to replicate imperfect DNA templates . . .
• The recent discovery of additional eukaryotic DNA polymerases...further complicates the already daunting issue of understanding the control systems that govern which DNA polymerase gains access . . . .
• A growing body of evidence suggests that an important additional level of control results from DNA polymerases being "coached" as to their correct biological role through interactions with other proteins associated with the particular DNA substrate . . . .
• In addition to their roles in chromosomal DNA replication, DNA polymerases participate in numerous DNA repair pathways, including double-strand break repair, mismatch repair, base excision repair and nucleotide excision repair . . . .
• Elaborate regulatory controls and a sophisticated system of protein-protein contacts ensure that the...gene products carry out their appropriate biological roles. However, as is so often the case in science, the discoveries of today are posing even more challenging questions for tomorrow.
And this all takes place in the simplest kinds of bacteria! Remember that Darwin did not know any of this. To the Darwinians, cells were little blobs of unknown stuff called “protoplasm” and it was easy to talk glibly about it arising in some warm little pond and evolving into higher organisms. As Michael Behe said, the cell was a “black box” to Darwin, but now we have opened the box and are staring with awe at the contents. Does a system as complex as a robotic factory, complete with fail-safe mechanisms, feedback, automatic repair and inspectors originate out of ooze? No way! Darwin himself said, “If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find no such case.” Well, biochemistry is providing cases by the truckload. How do you spell DNA? “Darwinism Not Adequate.”