[MHGinTN]

Don't know if you want some input, but here's an argument for soul entering at conception: there is the possibility that the soul IS connected to the spacetime universe, to the organism that is alive, and is disconnected from the organism at death of the organism; as such, the connections between the intangible and the tangible would be a 'building process', with perhaps the organ systems being infused with the soul of life as they develop, thus 'dis-infused' at death; the whole of an organism is 'arrived at' by a process of developing complexity so the degree of soul connection would likely follow thew same building process.

[meat skinner]

Interesting. Yes, there is that possibility, but isn't sperm "alive"? It is motile.

[TigersEye]

...the whole of an organism is 'arrived at' by a process of developing complexity so the degree of soul connection would likely follow thew same building process.

Perhaps 'the whole of an organism' is arrived at when two incomplete copies of parent DNA fuse together to make one complete, unique and viable copy of DNA. Perhaps that is the magic moment when the immortal soul of a human joins its biological shell.