The issue here is twofold: the doctrine of the biological transmission of sin from soul to soul and also the Traducian origin of the human soul. According to these, then, the origin of both our soul and sin is strictly physical or biological. This doctrine was unknown in the writings of history that I have studied until invented by Tertullian and confirmed subsequently by many 'church fathers'--perfected by Augustine.

If sin is strictly a spiritual principle ('naked and not ashamed'--our physical nakedness being only a 'type' of our spiritual sin)--then each soul is created directly by God (as affirmed in Jewish antiquity and the scriptures) and the sinful nature is a part of that soul's original estate in this life, not transmitted by biology.