The Church teaches that our best understanding is that we are all descended from Adam, and from him inherit original sin. This is easily inferred from Scripture, but is less easily demonstrated from inheritance. This second method requires tracing back the lineage of the Y (male) chromosome. And so we reach our last common male ancestor who lived between 60,000 and 140,000 years ago. We can’t safely call him Adam because he may, in turn, descend from the first human being – who alone merits that name.
However we might modify our conclusion because in fact the late Albert Perry, who lived and recently died in South Carolina, who it turns out had a Y chromosome ancestor who lived over 300,000 years ago (New Scientist March 16, 2013). About 1,500 American men have the same genetic history. Since the first fossils of homo sapiens date from around 195,000 years ago it is assumed that his ancestor must have interbred with a non-human “cousin: species. This of course is not unknown: DNA analysis shows that our species interbred successfully with Neanderthals and Denisovans – and a small portion of their genes remain with us today.
Quite where this leaves Adam is not clear. Interestingly, an article in the Clergy Review many years ago (I forget the author) suggested that the problems of incest arising among Adam’s children might well have been avoided by mating with “cousin” species. That now looks like a good guess. Presumably the proportion of truly human children would have followed the Mendelian distribution.
It is not easy to spot the moment when an ancestor species turned into homo sapiens. I use the word “moment” by virtue of the fact that the spiritual aspects of the soul are either present or absent. It is easy to detect the genetic changes which have occurred in the six million years since we last shared an ancestor with the apes. The changes are small, but small genetic mutations can play out as major changes in their effects. At what point in this development did our ancestors acquire a soul?
We need to consider the question raised by the Neanderthals. They broke away from the line before homo sapiens appeared. But they have the same brain capacity as us, they certainly made tools, and they had the crucial “speech” gene which at least suggests that they might have mastered speech. Indeed, even in our direct line, previous species of homo had developed different forms of tool. Did they have immortal souls and, if so, were they subject to original sin?
If we look to Genesis in order to solve this problem, we have to be careful. What Genesis gives is a true picture of the underlying reality framed within the knowledge available to the writer. So we learn that our first parents had freewill from the beginning but they did not yet “know” good and evil. But this was knowledge in the semitic sense – not a matter of information but a matter of experience. Taking the fruit of the tree in defiance of God’s command was the first, but sadly not the last, experience of evil by the human race. And the second, as we might have expected, was the realisation through shame at their nakedness of the dangers involved in our sexual instincts.
Here Freud’s concept of the id as the source of instinctual desires, and working on the pleasure principle, is relevant. Essentially a human being is a single entity but with two aspects. The first is the biological aspect which acts, as all the non-human animals do, in response to pleasure and pain, the second is the infused spirit whose aspiration is love. The metaphor of a ‘higher’ and ‘lower’ nature is instructive, for our lower nature, like gravity, is the default from which we can only rise by turning to the good which our higher nature presents.
If this is so, then the potential injustice of our inheritance of original sin ceases to be an issue. What we inherit is the whole of human nature with its inbuilt tension between animal appetite and aspiration. We cannot complain about this, because that is our identity. In the story, Adam and Eve actualise lower nature through their choice of disobedience, just as we actualise it in turn.
I write here as if turning to the good were a function of our native power. But, without attempting to develop the concept here, I note that it is the free use of the grace earned by the Redemption which is needed. That is a huge matter.
So, although we can only infer at what point in the development of homo the human soul was infused, we do know that it must have been the point at which our first ancestor recognised right and wrong and was free to choose the good and to reject the evil. Although the record is partial it is possible to suggest dates when skills of various kinds were achieved. They range from the development of tools to the development of speech, symbolism and religious awareness. In a future column I will look at some of the landmark skills the anthropologists have detected.
I have of course omitted reference to “mitochondrial Eve” – the mother of all the living. She has been traced and dated by a similar method since mitochondria is passed (relatively) intact from mother to child; it is racial DNA rather than personal. But, as far as Genesis is concerned, the omission is not of consequence since, being made from Adam, she inherited his DNA except for the substitution of one chromosome.