I would say that at whatever point you decide to be the origin of man on earth, sin was there. (I don’t consider the garden “on earth”, but rather a spiritual Eden similar to what we see as heaven.)
Feels like a trap…I read Genesis more in a poetic sense, not as literal as most. I believe that the story is inspired by God to relate the origin of sin and the natural compulsion of man to sin. I think the purpose is to relay the concept that without dark, you don’t know what light is…without evil, good is not understandable. Without sin, we do not know righteousness. God has a purpose for us, and I think the beginning of understanding that purpose is to understand good vs evil, sin vs righteousness, light vs dark and which side of the fence do we want to fall on…
As stated in other recent threads, I don’t expect to sway you, nor feel a need to. My comment was to say that as a Christian I think science confirms my beliefs, where most of my Christian brothers think the two are at odds.
In regard to the question of the thread, my answer is no, the biblical doctrine of original sin is not just a Genesis question, nor is it solely a doctrine of the first humans. The doctrine as I read it appears throughout the bible and can be considered as a more broad issue of human psychology (science) if you take “original” to mean the origin of each human individually. So, I assign a double meaning to “original sin” to mean the beginning of man with God in Eden (in a poetic sense), and the beginning of my own flesh when I was born. We are all born to flesh with a sin nature that is part of that flesh. Finding a connection with the Holy Spirit gets you somewhat out of that fleshly pattern, but the sin nature is still part of all of us, regardless of how righteous or moral an individual thinks s/he might be.