As an analogy one can imagine an intelligent amoeba with a good memory. As time progresses the amoeba is constantly splitting, each time the resulting amoebas having the same memories as the parent. Our amoeba hence does not have a life line, but a life tree.

illustrating the branching of individuals in many worlds each time an observation is performed, in an early draft of his doctoral dissertation (1950s). Accessible at Read original documents of Nova's Parallel worlds documentary of Hugh Everett's work.