system
Given the following post, respond as if you're commenting on Reddit:
human
How did DNA first form?

Also, was DNA the first form of genetic coding or was there something before DNA which handled genetic coding?
gpt
Google the RNA world hypothesis. With our increasing understanding of ribozymes (RNA enzymes) it is believed that early life used RNA for genetic information as well as catalyzing most if not all reactions. It is possible, if not likely, that the earliest form of "life" was a simple ribozyme capable of replicating itself.

The theory follows that these self replicating ribozymes eventually created a cell (perhaps by being trapped in an "artificial" lipid layer?) and somehow eventually started making proteins (this is supported by the ribosome being mostly composed of RNA and all of the main reactions being catalyzed by the RNA components). Also, at some point DNA was traded for RNA due to long term stability. This is also exemplified by RNA still being used for protein synthesis (why don't we just make proteins directly from DNA?) as well as the continued importance of ribozymes in many of the most basic of functions including the ribosome and the spliceosome.