Q**: What are Catholics bound in faith to believe about human origins? Was Adam really our first parent, or could there have been an entire race of original human beings endowed with immortal souls – an accurate rendering of the Hebrew word “adam”?
Father Oakes: In my opinion, the debate about “monogenism” – the doctrine that says that all humans share the same primal parents – and “polygenism” – that the races come from independent lines of evolution – has been misconceived, for both are true depending on where you stop along mankind’s family tree.
All of us, after all, have one set of parents, but four grandparents, eight great-grandparents and so on, all the way back. But eventually, the number of these putative ancestors will grow absurdly large: in each generation, the number of my direct ancestors must grow exponentially: two, four, eight, 16, 32 and so on.
Even more strangely, the number of actual human beings inhabiting the planet will begin to shrink the further back into history we go. This means that, eventually, the further back you go in history, this vast number of ideal “slots” of ancestors will have to be filled by just one person or two; for example, if two of my grandparents were first cousins, I would have only six great-grandparents, not eight.
Fascinating studies have been done, using the genealogical records of the Mormons in Utah, to show how most Caucasians now dwelling in the United States can trace their ancestry back to just one couple living in eighth-century Europe; and no doubt Americans of other racial background could do the same with their native lands.
For a riveting account of this field of “population genetics” for the general reader, see “The Mountain of Names: A History of the Human Family,” by Alex Shoumatoff.
So does this process ever reach one couple? According to genetics, yes. In fact, according to the theory of evolution, it could hardly be otherwise, the whole point of the theory being to stress common ancestry.
Of course, if genetics establishes that there is a primal couple, that couple could then trace its ancestry back to a common set of ancestral parents. So according to genetics, both monogenism and polygenism are true, but at several times and at various points along the evolutionary tree. See “The History and Geography of Human Genes,” by Luigi Luca Cavalli-Sforza.
The theological question then becomes: Do we ever reach the Adam and Eve described in the Bible? Here I think we get to the core of the issue.