Fermi Paradox addendum
A couple things I missed in the previous post. ( cut for nerdiness )
So, it seems likely that quite a few of those million or so lifebearing planets in the galaxy will have not just life, but multicellular life on them, assuming they have been around about as long as Earth, which needed about 4 billion years to build up enough atmospheric oxygen to support large, complex creatures.
So, it seems likely that quite a few of those million or so lifebearing planets in the galaxy will have not just life, but multicellular life on them, assuming they have been around about as long as Earth, which needed about 4 billion years to build up enough atmospheric oxygen to support large, complex creatures.