In an earlier thread — Could Adam and Eve Have Been the First Embodied Persons Within an Existing Homo sapiens Population? — the discussion gradually moved well beyond the original question. We ended up talking about animals, subjects of experience, personal subjects, memory, moral responsibility, and what kinds of evidence might matter when we try to determine whether we are dealing with a person. That raised a broader question which seems to me worth a thread of its own: What happens when t...