by Jonathan Sarfati

Our information is stored on the famous DNA double helix molecule. This is so efficient that just five round pinheads full of DNA could hold all the information of the earth’s entire human population.1 Just one of these pinheads would have 2 million times the information content of a 2 TB hard drive. And each of our 100 trillion cells has 3 billion DNA ‘letters’ (called nucleobases) worth of information.2

But chemically, DNA is actually a very reactive molecule (and RNA is even more so), so it’s highly implausible that it could have arisen in a hypothetical primordial soup.3 Indeed, about a million DNA ‘letters’4 are damaged in a cell on a good day. One common form of DNA damage is called alkylation—this means a small hydrocarbon group is attached to one of the ‘letters’, and there are many places for the attachment. This changes the shape enough so it can no longer fit into the double helix. This can prevent DNA replication or reading the gene.

So living creatures must have elaborate DNA repair machinery. For example, there is ‘base excision repair’: special enzymes called DNA glycosylases run down the DNA molecule, detect the damaged ‘letter’, grab it, put it in a specially shaped pocket, then chop it out. Then other enzymes repair the resulting gap….

Continue Reading on