- They both reproduce - They both eat - They both have some sort of a nervous system - They both breath - They both live and die
Many plants, and some animals such as birds, can produce fertile hybrids after being separated for millions of years. Especially true for organisms that have reproductive barriers besides genetic and physical incompatibility (different pollinators, geographic separation, birdsong differences, etc).
No doubt there are edge cases.
Actually they probably aren't because I guess otherwise all different planets would have them (but hey we are also only here so far).
There's interesting question what would god-like(unlimited power over mater and limitless knowledge) entity do? I guess killing oneself and recreating with sprinkle of rng makes some sense after such event as you probably get bored thus I'm speculating that universe could be god itself (if it's bound by same laws of physics - if not then IDK). Don't ask me what I'm smoking :p