Humani Generis and Evolution

"When, however, there is question of another conjectural opinion, namely polygenism, the children of the Church by no means enjoy such liberty. For the faithful can not embrace that opinion which maintains that either 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. Now it is no way apparent how such an opinion can be reconciled with that which the sources of revealed truth and the documents of the Teaching Authority of the Church propose with regard to original sin, which proceeds from a sin actually committed by an individual Adam and which through generation is passed on to all and is in everyone as his own."

Pope Pius XII, Humani Generis, 1950, Article XXXVII

Contrary to popular assertion, polygenism refers to multiple ancestral populations, not couples. Likewise, monogenism refers to a single ancestral population, not couple. That being said, polygenism is condemned by modern biology just as much as it is condemned by the Church. All fossil and genetic evidence indicates that humanity had a single origin in Subsaharan Africa.

That single origin has a long and complicated history within Prehistoric Subsaharan Africa. The Genus Homo began in the form of Homo habilis roughly two and a half million years before the time of Jesus Christ. The evolution from initial Homo habilis to modern Homo sapiens went through several steps, notable among which were Homo ergoaster and Homo erectus.

The Y Chromosomal Adam, who lived about 215 millennia before the time of Jesus, was by no means the only man alive at the time. He was, however, the only man from his time whose particular copy of the human Y Chromosome (and therefore, whose patrilineage) would survive the subsequent population collapses of latter Prehistory.

His female counterpart is known as the Mitochondrial Eve, and she lived about 201 millennia before the time of Christ. She was likewise not the only woman of her time, but rather, the only one whose mitochondrial genome (and hence, matrilineage) would survive the same population collapses later on the Prehistoric timeline.

Note that the Y Chromosomal Adam and the Mitochondrial Eve, despite an admittedly understandable popular belief, could not have been husband and wife. He was already dead for 14,000 years at the time of her conception and birth.

Who then was the Biblical Adam, in relation to the two Prehistoric humans from hundreds of thousands of years before Jesus' era who are explained above? Was he the Y Chromosomal Adam, or was he the husband of the Mitochondrial Eve? Neither. Based on the clarifications given in Humani Generis, the Biblical Adam was another ancestor from long before the times of the Y Chromosomal Adam or the Mitochondrial Eve.

Given the Encyclical's emphasis on Original Sin, the relevant Adam is by definition the first sinner. The precise temporal and physical nature of his sin is of no particular concern, although perhaps he was a tribal chief who committed hypocrisy by breaking one of his own decrees.

Though the Encyclical mentions the soul and reiterates that it must be immediately created by God, this is obvious. As discussed and defended in Idealism and the Soul, the soul is a description of the person's relationship with God. Given God's nature as the Creator, all relationships with him are necessarily initiated by him, hence the soul is indeed an immediate creation of God.

As long as the Biblical Adam lived before the time of the Y Chromosomal Adam, all modern humans are indeed descendant from him albeit subsequently also descendant from the Y Chromosomal Adam. Fortunately, the fossil record indicates that the capacity for worship and for sin developed long before the time of the Y Chromosomal Adam.

A little boy died from a bacterial infection, at the age of 8, roughly one million years before the time of Jesus. He was indeed a human, but a different type of human, specifically Homo ergoaster as opposed to Homo sapiens. Shortly after his death, his family gave him a ritual burial in the mud of a nearby river bank. All of this is known from the analysis of his fossil, which was discovered in 1984, and paleontologists have named him Turkana Boy.

If these Prehistoric people were capable of ritual burials for their dead, which the fossil record makes clear that they were, they were therefore capable of worship. Consider a group of Homo ergoaster gathered around a campfire, conducting a worship service of some kind albeit primitive. By some strict interpretations of Humani Generis based on Substance Dualist rather than Idealist interpretations of the soul, one might be expected to think that God would respond by saying, "Ha ha, who cares? I don't feel like giving you a soul yet." That notion of God is of course abhorrent, not to mention contrary to the very goals that a loving God would accomplish over a million years later by way of his death on a cross and his resurrection.

The astronomical and geological records, and even the evolution of humans ourselves, all indicate a Universe that is billions of years old rather than merely thousands of years old. This is all the more reason to say of Jesus, "Late in time, behold him come," as found in the hymn Hark the Herald Angels Sing.

Objection 1: "The Early Church Fathers all took the Garden of Eden as an absolute historical account!"

No, they did not.

"It was not only, however, with the Scriptures [composed] before the advent [of Christ] that the Spirit thus dealt; but as being the same Spirit, and proceeding from the one God, He did the same thing both with the evangelists and the apostles—as even these do not contain throughout a pure history of events, which are interwoven indeed according to the letter, but which did not actually occur. Nor even do the law and the commandments wholly convey what is agreeable to reason. For who that has understanding will suppose that the first, and second, and third day, and the evening and the morning, existed without a sun, and moon, and stars? And that the first day was, as it were, also without a sky? And who is so foolish as to suppose that God, after the manner of a husbandman, planted a paradise in Eden, towards the east, and placed in it a tree of life, visible and palpable, so that one tasting of the fruit by the bodily teeth obtained life? And again, that one was a partaker of good and evil by masticating what was taken from the tree?"

Origen, De Principiis 4:16

"Often, a non-Christian knows something about the Earth, the Heavens, and the other parts of the world, about the motions and orbits of the stars and even their sizes and distances...and this knowledge he holds with certainty from reason and experience. It is thus offensive and disgraceful for an unbeliever to hear a Christian talk nonsense about such things, claiming that what he is saying is based in Scripture. We should do all we can to avoid such an embarrassing situation, which people see as ignorance in the Christian and laugh to scorn. The shame is not so much that an ignorant person is laughed at, but rather that people outside the faith believe that we hold such opinions, and thus our teachings are rejected as ignorant and unlearned. If they find a Christian mistaken in a subject that they know well and hear him maintaining his foolish opinions as based on our teachings, how are they going to believe these teachings in matters concerning the resurrection of the dead, the hope of eternal life, and the kingdom of heaven, when they think these teachings are filled with fallacies about facts which they have learnt from experience and reason. Reckless and presumptuous expounders of Scripture bring about much harm when they are caught in their mischievous false opinions by those not bound by our sacred texts. And even more so when they then try to defend their rash and obviously untrue statements by quoting a shower of words from Scripture and even recite from memory passages which they think will support their case ‘without understanding either what they are saying or what they assert with such assurance’ (1 Timothy 1:7)."

Saint Augustine, De Genisi Ad Litteram I 19:20

Objection 2: "How can we inherit Original Sin if we are not related to the sinners?"

This objection stems from a misinterpretation of evolution, as if it claimed that not all humans are genealogically related. Not only does Evolution affirm that all humans are genealogically related, but furthermore, it goes beyond and affirms that all life is genealogically related. If you trace back enough generations, you are eventually related not only to all other humans but furthermore to all living things, even down to every bacterial cell.

Quod Erat Demonstrandum.