Pope Benedict (when he was not yet the Pope) wrote in his book In the Beginning…, about Original Sin and what is means to the human condition. Here is an excerpt from the book:
“In the Genesis story that we are considering, still a further characteristic of sin is described. Sin is not spoken of in general as an abstract possibility but as a deed, as the sin of a particular person, Adam, who stands at the origin of humankind and with whom the history of sin begins. The account tells us that sin begets sin, and that therefore all the sins of history are interlinked. Theology refers to this state of affairs by the certainly misleading and imprecise term ‘original sin.’ What does this mean? Nothing seems to us today to be stranger or, indeed, more absurd than to insist upon original sin, since, according to our way of thinking, guilt can only be something very personal, and since God does not run a concentration camp, in which one’s relative are imprisoned, because he is a liberating God of love, who calls each one by name. What does original sin mean, then, when we interpret it correctly?
*“Finding an answer to this requires nothing less than trying to understand the human person better. It must once again be stressed that no human being is closed in upon himself or herself and that no one can live of or for himself or herself alone. We receive our life not only at the moment of birth but every day from without – from others who are not ourselves but who nonetheless somehow pertain to us. Human beings have their selves not only in themselves but also outside of themselves: they live in those whom they love and in those who love them and to whom they are ‘present.’ Human beings are relational, and they possess their lives–themselves–only by way of relationship. I alone am not myself, but only in and with you am I myself. To be truly a human being means to be related in love, to be of and for. But sin means the damaging or the destruction of relationality. Sin is a rejection of relationality because it wants to make the human being a god. Sin is loss of relationship, disturbance of relationship, and therefore it is not restricted to the individual. When I destroy a relationship, then this event–sin–touches the other person involved in the relationship. Consequently sin is always an offense that touches others, that alters the world and damages it. To the extent that this is true, when the network of human relationships is damaged from the very beginning, then every human being enters into a world that is marked by relational damage. At the very moment that a person begins human existence, which is a good, he or she is confronted by a sin-damaged world. Each of us enters into a situation in which relationality has been hurt. Consequently each person is, from the very start, damaged in relationships and does not engage in them as he or she ought. Sin pursues the human being, and he or she capitulates to it.” *
– Joseph Cardinal Ratzinger, "In the Beginning…"
According to this excerpt, we see here that Original Sin is propograted not through a genetic condition (e.g. through a bloodline) but through relationships. Specifically, we see the breakdown of our connection to other persons (including God). Orignal Sin is perpetuated because human beings enter a world that is mained through sin. Genetic monogensim and genetic polygenism are functionally irrelevant for the purposes of the propogration of Original Sin and its incumbent source.
