Damaged DNA: A Darwinian Achilles Heal

Buildup of Damaged DNA in Cells Drives Aging Process, According to Study in Nature highlights the essential nature of genetic repair mechanisms.

Cumulative damage to DNA has been associated with the aging process. The study revealed that mice, with a single disabled gene involved in the repair of DNA, suffered the effects of a resulting disease that led to their deaths. There are many such repair genes in mice and humans. Repair genes are found in unicellular organisms as well. It only took one such disabled gene to engender the lethal result.

To quote from the source: "However, it shows how important it is to repair damage that is constantly inflicted upon our genes, even through the simple act of breathing.” In other words damage to DNA is an inevitable aspect of living. It is not occasioned by temporary environmental factors. It was there on prebiotic earth during the imagined RNA world. So how would any nucleic acid, fortuitous enough to have acquired sequential encoding specificity, retain it in the absence of a preexisting repair mechanism?

An interesting part of the study was the finding that the aging process is linked to the suppression of genes whose proteins are involved in metabolic pathways that promote growth. This suppression seems to protect against DNA damage induced stress. About half of the athletes and others who have consumed human growth hormones have experienced arthritic side effects. It's only speculation but, perhaps the supplemental HGH undoes a process that protects against damaged DNA and consequently triggers arthritis.