[Mrs. Don-o]

BTW, Isaiah said the Virgin would "conceive and bear" a son: not just bear ("carry") but "conceive" and bear. Conception is the very moment when the mother's haploid genetic contribution becomes a constitutive part of her child's bodily inheritance.

If Mary was not Jesus' genetic mother, she did not conceive Jesus in her womb, but just toted Him around like some kind of incubator. If that's the case, then Jesus was not a Jew --- nor, for that matter, a member of the human race.

And if that is the case, then Jesus was mistaken when He said that "Salvation is from the Jews" (John 4:22). Come to think of it, all the Messianic Scripture prophecies about "Abraham and his seed," and the Messiah as inheriting the throne of "David his father," are reduced to nonsense. And if Jesus is not a Jew, he could not have been the Jewish Messiah.

As I say, this denial of Mary's true motherhood obliterates Jesus' human and Jewish genealogy and kinship. It is --- outside of the Koran --- a completely new bit of weirdness. I find it mind-boggling.

Tagline from Acts 2:30

[MHGinTN]

And I would assert that conception is when the embryonic being implants in the uterine lining (or elsewhere in the case of ectopic implantations). The reason your assertion is wanting is because the embryo at the stage of zygote can become more than one individual human being. BUT upon implantation there is the one (sometimes having a second implantation very close and rarely two or more combine to form a chimera).[ I have a little free book at my blogpage which explains the biology for laymen, if you need to consult it. The link is on my profile page. Feel free to download it; more than 10,000 have done so already. ]

The ONE WHO was implanted/conceived in Mary is Jesus, by the authority of the Scriptures we may make that assertion. We cannot make an inference that GOD used Mary's chromosomes to create the body for Jesus. God did not give us the specifics to that level of certainty.