It's 4.5 billion years ago. The Earth is a hot, bubbling sphere of lava & hostile gases. And then suddenly... THERE IS LIFE!
But how did this first Earthly organism show up on our planet? And who was (s)he? A Giant Virus? An archaea cell?
Meet your Great, Great, Great, Great, Great, Great, Great, Great Grandmother, Luca.
If our earliest ancestor was indeed, as research suggests, a simple strand of chemicals that randomly happened to smush together in the perfect shape for fabricating its own decedents (also strands of chemicals) floating in a swamp of primordial ooze that was randomly struck by lightning... how did it evolve into the extremely complex multi-cellular plants and animals that exist today?