Here's a paper that seems to say that by making some reasonable assumptions about early-universe hydrodynamics, you can almost assume that life originated very

Here's a paper that seems to say that by making some reasonable assumptions about early-universe hydrodynamics, you can almost assume that life originated very early on. sdcc3.ucsd.edu/~ir118/STPA35F10/FirstLife_Sept19_JofC_arXiv.pdf That's why we see DNA fragments and possible microbial fossils in comets: DNA-based life originated well before the first planets. Weird speculation, but it does seem to hang together.