The emergence of coding is interesting and an active field of study but still not entirely found a consensus yet. One of the most interesting ideas is of an 'R

The emergence of coding is interesting and an active field of study but still not entirely found a consensus yet. One of the most interesting ideas is of an 'RNA World' [1]. Many of the oldest, first, most essential protein-like machines in your body aren't actually 'proteins' at all, but are RNA molecules that are enhanced structurally and otherwise by some protein helpers (ribosomes are the prime example). RNA has a lot more reactivity than DNA, so it can be an enzyme in a way DNA cannot. It's also more flexible (RNA is a single flexible cooked-noodle-strand, rather than DNA's double solid uncooked-noodle double strand). So RNA can fold in cool ways to make really crappy enzymes - but functional none-the-less. Proteins are way more versatile as enzymes, but way worse at encoding information (precisely because they become structurally 'stuck'). So you have the thought that everything started off with a dual-use molecule - RNA. And that RNA was used as a bootstrap to build enzymes that made two different kind of molecules - one for long-term information storage: DNA, and another for building better enzymes: proteins. It's an elegant idea. [1] https://en.wikipedia.org/wiki/RNA_world_hypothesis https://en.wikipedia.org/wiki/RNA_world_hypothesis