A theological-biological explanation of “the original sin’s transmission”

I just realized upon following the link myself that I had posted, I really should have included the whole verse for @RichardG (and others of us who have issues allowing God to be sovereign – @mitchellmckain?):

He has saved us and called us to a holy life – not because of anything we have done but because of his own purpose and grace. This grace was given us in Christ Jesus before the beginning of time,

2 Timothy 1:9