It is quite common to hear that Catholics have no problem with evolution. And this is at least generally true. The magisterium, for its part, seems very comfortable with evolution, at least as a scientific theory, more or less taking it for granted in any pronouncements that touch upon it. And a substantial majority of individual Catholics see no great difficulty with the theory despite the fact that the broader cultural narrative often portrays evolution as opposed to a biblical view of creation.
But there is one point where some Catholics raise an objection. What are we to make of the fact that the scientific data, especially since we have learned how to sequence genomes, points not to two original parents, but to an original breeding population of perhaps 10,000 individuals at some point in our distant past?
Pope Pius XII and evolution
In 1950, in the encyclical Humani Generis, Pope Pius XII cautiously granted Catholic scientists and theologians the freedom to pursue the question of evolution, declaring it was not impossible for Catholic faith that humans physically descended from prehuman ancestors, provided that it is acknowledged that the soul, being a spiritual and not a physical reality, does not evolve.
On the question of one set of parents (monogenism) versus more than one set (polygenism), he was particularly cautious. It was “in no way apparent” to Pius XII how theories of human origins that imagined more than two parents could be squared with the faith, and particularly with the doctrine of original sin.
So what is a Catholic to think if today’s science has shown to some real, if not perfect, degree of certainty that the modern human lineage did in fact derive from more than two parents?
Reasons for caution
A first thing to note is that Pius was quite careful in his choice of language. He did not teach that polygenism was incompatible with Catholic faith, but that, given the state of both scientific knowledge and theological reflection in 1950, it was not at all apparent how the two could be reconciled. Fair enough! But such a framing hardly handcuffs future scientists, theologians or popes.
A second consideration is to look at the date. Only a few years after the Holocaust, it was as important as ever to assert the unity of the human family. Various theories of evolution were in circulation at the time, some of them suggesting the independent development of different human lineages. Such theories could easily be used for political ends that treated some humans as less than others.
Pius certainly had this in mind. Original sin is, among other things, a doctrine about the unity of the human family. And so our current theory of evolution, which posits a common ancestry for all of humanity, is actually more amenable to Pius’ theological aims than the versions that rightly concerned him in 1950.
Finally, notice that, if having some human beings not descend from Adam and Eve is a problem, it was a problem long before evolution showed up. The Bible clearly presumes the existence of other humans in the Genesis narrative. Cain is worried that these folks are going to murder him! He is also the founder of cities.
People have found workarounds for this, of course, like the theory that Adam and Eve had dozens or hundreds or thousands of unmentioned children. But the Bible itself, including the Letter to the Romans, where St. Paul talks about all having sinned in Adam, feels no need for such explanations.
‘A larger idea of Divine Prescience and Skill’
Geneticists tell us that, in a population of 10,000 or so, it does not take many generations before everyone descended from that original group could also be descended from two specific members of that group. I grew up in a village where two people who had 13 children were grandparents to half the town in just two generations. So, from a genetic and mathematical point of view, it turns out that polygenism is not the problem it seems. Even if we were to insist that a coherent doctrine of original sin requires two original parents, polygenism is not insurmountable.
If Scripture is not troubled by the problem as it emerges in its own pages, and, scientifically, polygenism does not rule out a historical Adam and Eve, it is hard to contend that this, finally, is the stumbling block for the Church’s acceptance of evolution that cannot be overcome.
Let us recall that one of the preeminent Catholic theologians at the time Charles Darwin’s “On the Origin of Species” was published, St. John Henry Newman, viewed it with the utmost equanimity, famously saying, “Mr. Darwin’s theory need not then to be atheistical; it may simply be suggesting a larger idea of Divine Prescience and Skill.” Newman, at least, did not think that it implied a radical rethinking of traditional Catholic teaching about creation and the fall.
The magisterium’s recent approach to polygenism has been much the same as Newman’s approach to evolution in general, one of equanimity. There might be some interesting theological work to be done in light of this or that scientific development. But there is no threat to Christian faith here.
