[tiniestcabbage]

> And those early organisms would eventually [have] to move to the shallows and land and deal with all the masked radiation at some point.

Do they, though? Why is land the requirement? What's keeping life from, say, evolving to live deep underground? Or in the deep ocean? Both those places are heavily shielded from radiation, and organisms there wouldn't be affected much at all by not having a magnetosphere. Extremophiles on Earth get by just fine hanging around thermal vents, for instance. (Edit: this was mentioned above and I didn't see it - sorry for repeating.)

I think part of the problem with the Fermi paradox is that our base assumptions about what life needs are possibly a bit off. Maybe the fact that we have what we have is, well, quirky, and the fact that we evolved as living creatures that crawl around on the outside of our planet and need really fussy little temperatures to survive is just plain weird in comparison to the rest of the universe.

"Life as we know it" is a lot tougher criterion to meet than "life," I suspect.

[SoftTalker]

Life may be abundant. Intelligent life with technological civilizations is probably not. It took 4 billion years on earth. That’s 1/3 the age of the universe.

[dekhn]

These are all fair questions, and to go further, life may not even have required light at all- there are chemoautotrophs living deep in the rock that never see light.

I was going to say "obviously, nothing I said above would apply to life as we don't know it, like on the surface of a neutron star".