> over millions or billions of years one of the interesting constraints is you don't have billions of years. Life appeared on Earth within 100 million years of

> over millions or billions of years one of the interesting constraints is you don't have billions of years. Life appeared on Earth within 100 million years of the planet cooling down enough to have standing water, possibly even less, depending on your reading of the evidence that gets more disputed the farther back you go. It took 2 billion years for prokaryotes to turn into eukaryotes, and it took another billion for eukaryotes to go multi-cellular, but somehow the initial development of a self-replicating cell with a code took less than a tenth of that.