Expanding on this is the concept of panspermia, life spreading across worlds on its own. For all we know, the building blocks of life could be older than the Ea

Expanding on this is the concept of panspermia, life spreading across worlds on its own. For all we know, the building blocks of life could be older than the Earth itself. So, aside from playing by the same rules, different forms of life on different planets could actually have the same ancestors.