Thanks very much, Bit! The self-regulating of complexity of life amazes me. Just photosynthesis itself, on a molecular and electron-chemistry level, is so complicated that it seems like a Creator showing off. "Look, Ma! See what I did!"

I didn't know about fungi, Bacteria OR Archaea in solid bedrock. Totally anaerobic, I assume.

When I first read about Archaea, I guessed that the first life we would find off Earth would be their distant cousins. Good name, from "archaic". Alternatively, if we have to terraform Mars or moons of Jupiter or Saturn, it will start with something from their Domain.

Venus would be more of a challenge. Maybe something that could live in clouds of sulfuric acid mist?