Proxima b will also be lifeless. Min. self-sustaining ecosystem too complex to originate often or travel by meteor.https://twitter.com/NickSzabo4/status/624327771515256832 …
-
especially if a % of the planets are more evolved than earth is, I would think many advanced civilizations could have existed.
They'd be so far ahead (like us vs. ants) that w/i bllns of galaxies we've observed we'd see them (as we are obvious to ants).