Lately, I have taken to asking my religious friends and family this question: "Who was your first ancestor to have some kind of supernatural life after death (often received as asking about Heaven and Hell)?" I typically get some answers about expectations of seeing long lost relatives in a happy forever spiritual world, but then I clarify the question as not being about the ancestors you remember, or even just know about, but rather going back as far as anyone has had ancestors. Blank looks tend to indicate (of those I talk to, anyway) that this question is not the usual mental rumination. Many break out of that by falling (so to speak) back to Adam and Eve, which then opens the can of misunderstanding of Evolution that stops so many religious people from looking deeply at their own biological history.
Having opened that can, the first thing I usually have to get through is explaining the difference between the fact of common descent and the theory of how mutation and selection generates new species. We have facts from geology and the fossils and the DNA of all living things that allows us to make a direct factual inference building the Tree of Life. We know about our biological ancestors; that part is not theoretical in the common sense as differentiated from fact. Even if someone rejects the Darwinian mechanism of Natural Selection, and insists on faith that a divine hand makes the selections, we still have common descent, and can trace our ancestors back along the branches of the Tree of Life to simple cells a billion years ago.
Sometimes the discussion stops right there. No mater how factual common descent may be, it is not going to be accepted by people who want the story of Adam and Eve to be literally true. A 'just' metaphorical A&E story is a problem because lacking that discontinuity in the chain of ancestors, even if the chain is divinely directed, one runs up against the question of when in our common ancestors did a person first have an immortal soul, who has ever since been enjoying or suffering an "afterlife," that was not the case for his or her parents? It really is a difficult question because each of our ancestors going all the way back to the start of life, itself, was almost identical to its (yes, going back to before there was even gender) parent or parents. Yet if someone believes that he or she possesses a "soul" that is going to live on and meet up with long dead friends and family, that had to start sometime, but no such start can be found.
This explicit necessity of discontinuity in a chain that demonstrably has none, is an application of a way of thinking that I began considering while posting here on the old consciousness thread. Consciousness, is not an all or nothing thing so it can develop to some level gradually over time (as in the Sorties Paradox) with no supernatural discontinuity needed. However, not so for an "immortal soul"; you cannot "evolve" a supernatural afterlife. The question of when it came to be answers itself: it didn't.