Weekend Update

Origins of life

The Ethical Skeptic is a former intelligence officer who has a wide range of interests and a rigorous approach to understanding the world. I came across him on Twitter through his analysis of pandemic statistics. He is a remarkable erudite individual. I discovered his long-form writing recently and read this article on the evolution of DNA. I have a couple of degrees in chemistry, and I have spent many decades writing software. DNA is where these two disciplines meet. But the article went well beyond my understanding of the subject. I was relieved to read that when Skeptic took the ideas to a professor of genetics, these ideas were new to him.

I need to read the article again, but it reopened the question of why it is that all living things follow the same template so closely, and that all living things are so alike. Humans and slime moulds are, from a DNA point of view, 85% the same. I made up the stat, but it can’t be far off.

I don’t know enough about DNA coding of proteins to understand the argument, but he seems to be saying that DNA has been around since practically the beginning of time, at least as far as the Earth is concerned. Although I know that the base pairs form a very stable structure, and that there is a very neat mapping from codons to proteins, I have no idea what alternative arrangements of thymine, adenine, guanine and cytosine are stereochemically possible, whether other bases could be substituted, or why exactly 23 amino acids are optimal for building proteins and polypeptides.

I admire individuals who want to be known for their work, not for themselves. The other famous example is Satoshi Nakamoto. Long may he remain anonymous!