Genome Entry 2 : Life

In this chapter of the Genome book, Ridley begins by speaking about the history of life. He believes that life began with RNA instead of DNA. He claims that RNA is more chemically active and automatic than DNA. Prehistoric "ribo-organisms" eventually made up DNA from a evolutionary error and trial process because it was much faster and more reliable. Next, he discusses the Last Universal Common Ancestor or LUCA. It has been believed that LUCA is a sort of bacteria living in a hot marine environment. Bacteria attain their genetic inheritance by stealing the genes from one another. Now LUCA is believed to be more of a protozoan because the bacteria would have dropped the RNA so that it could reproduce faster. Doing that it would help them in evolutionary strength. In the end, Ridley states that life is physical history and it isn't a genealogical one. The history of life can only be found in the genome.