The Catholic Church indeed of all the Christian churches faces a particular quandary. The Council of Trent is quite explicit on the topic. Catholics are required to believe not only that Adam is the single father of the human race, but that Original Sin is passed on by physical generation from him to the entire human race. It’s not something symbolic or allegorical (although it is regarded as ultimately mysterious). The First Vatican Council reiterated the doctrine, as did Pope Pius XII in his 1950 encyclical Humani Generis.The claim is that this cannot be reconciled with what we know from genetics. He links an article
Unfortunately, the scientific evidence shows that Adam and Eve could not have existed, at least in the way they’re portrayed in the Bible. Genetic data show no evidence of any human bottleneck as small as two people: there are simply too many different kinds of genes around for that to be true. There may have been a couple of “bottlenecks” (reduced population sizes) in the history of our species, but the smallest one not involving recent colonization is a bottleneck of roughly 10,000-15,000 individuals that occurred between 50,000 and 100,000 years ago. That’s as small a population as our ancestors had, and—note—it’s not two individuals.I am not a scientist but this does not make sense to me. When we are talking about the origin of the human species how can we talk about the origin as 10,000 individuals? The theory is that we went from zero humans to 10,000 all at once? That seems a little problematic. Maybe science has not arrived at a final answer.
Now the idea that there are too many kinds of genes around makes sense. If that is the scientific problem then we as Catholics need to believe God did some sort of miracle to increase the genetic diversity of humanity. I have no problem believing that. I have often thought that God must have done something to avoid the problems that go with inbreeding because lots of inbreeding goes on in Genesis.
So it requires us to believe that the origin of man is a supernatural event. That God must have acted in ways outside if what we see in genetics today. But Catholics already believe in many miracles. Is this harder to accept then the virgin birth or the resurrection? I don't see it. Doing a natural analysis of a supernatural event has limited value. You can never prove a miracle impossible. Miracles are impossible or close to it. That is why we call them miracles.
What makes humans special is not their bodies. Human anatomy is not very different from other mammals. So God could have used an existing primate and breathed a soul into him. That could have been His clay that is referenced in Gen 2. Could He have breathed a soul into the offspring of Adam and Eve even when they conceived with a non-human primate? I don't see that speculation as being outside Catholic orthodoxy. God does a miracle every time a new human life is conceived. An eternal soul is created. A human person that has been stained by the original sin of Adam.
The big advantage the Catholic church has here is that it does not need to guard the integrity of scripture. The notion that not taking one part of the bible literally will open the doors to interpreting every miracle as figurative. The church can define what interpretations are legitimate. So when Tim Keller says something like :
[Paul] most definitely wanted to teach us that Adam and Eve were real historical figures. When you refuse to take a biblical author literally when he clearly wants you to do so, you have moved away from the traditional understanding of the biblical authority.Catholicism does not have that problem. We don't think the bible is an authority. It is a revelation. We have a living authority. So it creates a problem for the protestant understanding of the biblical authority.