(not a biologist) One thing I find interesting, that while the earth was cooling off from the molten lava stage, there would have been a period where water temp

(not a biologist) One thing I find interesting, that while the earth was cooling off from the molten lava stage, there would have been a period where water temperatures were cooling from about 180 degrees F to 120. RNA based life can reproduce at those temperatures, DNA based cannot. As the Hadean slipped into the Archean era, it would have been heaven for bacteria.