> It's fascinating to me that the complexity of life always goes up. Sounds like observer bias. In terms of number of individuals, the vast vast majority of l

> It's fascinating to me that the complexity of life always goes up. Sounds like observer bias. In terms of number of individuals, the vast vast majority of life on this planet is single cell prokaryotes, and always has been. And in terms of total bio-mass only plants exceed them but that's just because of how plants work (cover the surface with bio-solar-panels) Both bacteria and archaea haven't substantially changed in 3.5-4 billion years. They swap genes as needed, and drop them when they're too costly and unneeded. And they're dominant, and everywhere They were here since just a few hundred million years (or less) after the earth formed. And when conditions on the planet become more hostile again, in the long run it could be the case that eukaryotes are just a historical blip (and a fluke, to boot). And if there's something we recognize as life out there beyond earth... it's likely to look like prokaryotes. The galaxy might be swimming in that kind of thing. There is a strong philosophical/ideological bias in our culture to see the world in terms of "progress"; a teleological bias, seeing the universe as proceeding in stages towards some order. It just so happens we almost always seem to define this progress as "inevitably" leading to ... us, or "beyond" us into whatever fantasy for the future is laying dormant in the present. It feels remarkably pre-Copernican.