s9e7 may look at first glance like it's tackling evolution, but it's actually a badass critique of god that takes evolution as its theme. rick's primary goal throughout the episode was simply to escape from this prison. that is, until he sees that even in morty's most innocent, most harmless form, the one who by his own will refuses to join the cycle of violence and chooses a different path for himself, only ever choosing to be of use to other living things, he still incurs the wrath of god. the moment he sees this, he changes his own cycle, shifting his goal from escaping to killing. and he pulls it off, too. in this episode rick actually killed god. as for no one in the prison being innocent, that's a critique aimed at human existence itself.