12 August is the 60th anniversary
of Humani Generis, by Pius XII.
While Pius was willing to concede that there was reason to believe the human body was the product of evolution, he was adamant that the special status of Adam as the father of the human race should not be a matter of question. "For the faithful," he wrote, "cannot embrace that opinion which maintains either that after Adam there existed on this earth true men who did not take their origin through natural generation from him as from the first parent of all or that Adam represents a certain number of first parents."
Pius declared that it was not apparent how such a theory of a founding population of humans, and not a single couple, could be reconciled with original sin. That Catholic doctrine regards the Fall as an historical rebellion against God; a sin actually committed by an individual and which is passed on through the generations from him to all men and women.
Subsequent research into genomics, however, has settled this question against Pius. It's not that scientists cannot trace human ancestry back far enough to an Adam and Eve; it's that in principle, the level of genetic variation present in the species today rules out a founding population with fewer than several thousand individuals.
A document drawn up for the Congregation for the Doctrine of the Faith in 2004, Communion and Stewardship, tacitly accepted the founding population theory of human origins. Communion and Stewardship was not widely publicized within the Catholic Church, and certainly did not make its way down to the pulpits for the general churchgoer in the way that an official encyclical would. And this raises the question of unfinished business when it comes to evolution and Christian theology.
For example, if the soul is to be considered a direct creation of God, distinct from the evolution of the human body, what does this tell us about its fundamental nature? Does the soul any longer have a nature, in the classic sense that medieval theologians inherited from Aristotle? Or is it to be understood in the more dualist terms of Descartes, a position previous popes have not approved? Should a future pope elaborate on this?
I doesn't seem that the Pope made an ex cathedra
, infallible statement when he said that the first humans were one couple (rather than, say, a population of 1000 individuals). It seems that the Orthodox take a more promising position that, since Darwinian evolution is not a threat to the Church itself, there is no need to make official statements about it.