In the book of Genesis, Cain murders his brother Abel. Then God punishes him with exile. Subsequently, Cain married a wife, and they conceived a son, Enoch. Afterward, Cain built a city and named it after his son.

[Genesis 4]
{4:1} Truly, Adam knew his wife Eve, who conceived and gave birth to Cain, saying, “I have obtained a man through God.”
{4:2} And again she gave birth to his brother Abel. But Abel was a pastor of sheep, and Cain was a farmer.
{4:3} Then it happened, after many days, that Cain offered gifts to the Lord, from the fruits of the earth.
{4:4} Abel likewise offered from the firstborn of his flock, and from their fat. And the Lord looked with favor on Abel and his gifts.
{4:5} Yet in truth, he did not look with favor on Cain and his gifts. And Cain was vehemently angry, and his countenance fell.
{4:6} And the Lord said to him: “Why are you angry? And why is your face fallen?
{4:7} If you behave well, will you not receive? But if you behave badly, will not sin at once be present at the door? And so its desire will be within you, and you will be dominated by it.”
{4:8} And Cain said to his brother Abel, “Let us go outside.” And when they were in the field, Cain rose up against his brother Abel, and he put him to death.
{4:9} And the Lord said to Cain, “Where is your brother Abel?” And he responded: “I do not know. Am I my brother’s keeper?”
{4:10} And he said to him: “What have you done? The voice of your brother’s blood cries out to me from the land.
{4:11} Now, therefore, you will be cursed upon the land, which opened its mouth and received the blood of your brother at your hand.
{4:12} When you work it, it will not give you its fruit; a vagrant and a fugitive shall you be upon the land.”
{4:13} And Cain said to the Lord: “My iniquity is too great to deserve kindness.
{4:14} Behold, you have cast me out this day before the face of the earth, and from your face I will be hidden; and I will be a vagrant and a fugitive on the earth. Therefore, anyone who finds me will kill me.”
{4:15} And the Lord said to him: “By no means will it be so; rather, whoever would kill Cain, will be punished sevenfold.” And the Lord placed a seal upon Cain, so that anyone who found him would not put him to death.
{4:16} And so Cain, departing from the face of the Lord, lived as a fugitive on the earth, toward the eastern region of Eden.
{4:17} Then Cain knew his wife, and she conceived and gave birth to Enoch. And he built a city, and he called its name by the name of his son, Enoch.

Several related questions arise from this story. Where did Cain get his wife? How could he build a city if the only persons on earth at the time were Adam, Eve, and their immediate descendants? Who would find and kill Cain if only his close relatives were on earth at the time? Several clarifications are needed to understand the answers.

1. There are two types of incest.

Incest, in this context, does not refer to child abuse, but to the question as to whom one may marry. Incest in the direct line is intrinsically evil and always gravely immoral. You may never marry a parent, child, grandparent, grandchild, etc. However, incest in the collateral line is a matter of degrees, and so it is not intrinsically evil; it depends on the circumstances.

May you marry someone who is related to you? We are all members of the same human family. We are all related. So you are always marrying someone who is at least distantly related to you. Currently, under Church law, a Catholic may not marry someone who is related in the first or second degrees of the collateral line: siblings, first cousins. A Catholic may marry someone related in the third or fourth degree, second or third cousins, only with a dispensation. Beyond the third degree, Catholics are free to marry.

When the human race was just beginning, the children of Adam and Eve had no one they could marry other than siblings. And, as one generation followed another, the descendants of Adam and Eve could marry persons more distantly related, such as first or second cousins. Since they had no one to marry, at the inception of the human race, other than close relatives, God permitted marriage in the collateral line. God may permit, by dispensation, anything that is not intrinsically evil. The reason that God cannot dispense from intrinsically evil acts is that He would then be contradicting his own Nature by permitting inherently evil acts.

That a dispensation was given is proven by the fact that Abraham married his half

So the first point is that Cain may have married a sister. However, this answer does not suffice to explain the city that he built, or his fear of being killed as he wandered in exile. How can one wander in exile, and meet strangers if the only human persons are one’s close relatives?

2. The lineage described in Genesis may include many skipped generations.

Jesus is called the son of David, even though many generations intervened between the two. Similarly, Cain and Abel might not have been the immediate descendants of Adam and Eve. The story of Cain and Able, like many stories in the first eleven chapters of Genesis, is a highly figurative retelling of historical events. If so, then there would be many other human persons on earth, generations after Adam and Eve. This would explain the building of a city and the fear that Cain had of being killed by strangers as he wandered in exile. And the same is true for the other named generations from Adam to Noah.

3. Adam and Eve may have lived as long as 50 to 80 thousand years ago.

According to anthropologists, anatomically modern humans (AMHs) began about 200 thousand years ago. They had bodies much like ours today. They did not look like apes or lower primates. However, they also did not have the ability to reason abstractly. This is proven by the fact that they did not develop a civilization: no cities, no schools, no science, no politics, no commerce, no art (nothing beyond what an ape could do today), no evidence of language, and nothing that would show the ability to understand and reason like human persons today.

Then, somewhere in the range of 50 to 80 thousand years ago, behaviorally modern humans (BMHs) began. And they very quickly built a complex civilization with cities, schools, science, politics, commerce, art, and language. The BMH had the ability to reason abstractly. As a result, they quickly outcompeted the AMHs, who became extinct.

My thesis is that Adam and Eve were the first two behaviorally modern humans. They had the ability to reason abstractly because they had free will and the gift of an immortal soul. Evolution could not produce free will, reason, or an immortal soul. Evolution was guided by God to produce the human body. But evolution hit a glass ceiling, since it could not evolve the attributes of true persons (free will, reason, immortal soul). So God created Adam and Eve miraculously, but patterned after the highest form of life that had evolved on earth.

Adam and Eve must have lived about 50 to 80 thousand years ago. Their descendants soon became very numerous. If a couple, on average, produce 4 children who survive to adult age and who reproduce, they double their number each generation. The progression from two to two million then takes only 20 generations (not counting the first). In many cases, the descendants of Adam and Eve may have produced more than 4 children who survived to reproduce. And at 40 years per generation, only 800 years are needed for Adam and Eve’s descendants to expand to millions of persons.

If Cain was not the first generation after Adam, then you can easily understand how he could have lived in a time of many other persons. He would not have difficulty finding a wife who was not closely related, nor in finding persons to inhabit a city that he founded.

4. We believe in Adam and Eve based on faith.

The above theory is consistent with our current scientific knowledge. There is no scientific proof that Adam and Eve existed. But there is no proof that they did not. Science cannot trace the origins of the human race to a point below thousands of individuals.

Faith requires belief that Adam and Eve were two real historical persons. The doctrine of original sin depends on the existence of Adam and Eve, and the doctrine of the Immaculate Conception depends on original sin. The Church also teaches that we are all descendants of Adam and Eve. So it is not possible to hold that Adam and Eve were merely the progenitors of everyone alive today. The idea called polygenism, in which the human race had more than two first parents, is incompatible with these doctrines.

by
Ronald L. Conte Jr.
Roman Catholic theologian and translator of the Catholic Public Domain Version of the Bible.

Please take a look at this list of my books and booklets, and see if any topic interests you.