Let us assume for the discussion that I accept God used an ovum from Mary's ovary to conceive Jesus. This would mean Jesus has at minimum, 23 chromosomes from Mary and thus from all whom she is descended, including Adam. The normal human complement of chromosomes is 46, so Jesus also has, at minimum, 23 chromosomes from 'a father' source.
Okay so far? ... The question I would ask of you then is upon which chromosome is the original sin of Adam carried? Since Jesus was without sin, it would appear you need, for insurance, that the chromosome comes through the mother's gene pool, right? So the sinless nature of Mary means she either had such a chromosome and it was 'cured' before she implanted in her mother's womb, or this 'sin chromosome' was cured before she was born. Is this getting a bit too over the top yet? ... In anticipation of your response, allow me to post asecond possible explanation, one no more fantastic than the assumption that Mary was born sinless.
What if the 'sin chromosome' is from the father genetic pool. Could The God Who created the entire Universe and thus all that is in it have take a spermatozoon from Adam before the fall and brought that 23 chromosomes to the scene of Mary's conceiving in her womb? ... Can we answer in any meaningful way just where the spermatozoon came from for the conception of Jesus, if we assume that the ovum came from Mary's ovary?
At this point I would imagine you are in favor of God dividing the ovum of Mary before it separated into two sets of 23, and by miracle God then caused the ovum to become a complete zygote with the sex of the resulting new being as a male. [This is contrary to the result when this happens in nature, that an ovum becomes a zygotic new life without spermatozoon. But for our discussion we will let that slide ... we are going to get to nothing short of the miraculous with this anyway!]
HOWEVER, if you are not willing to go down these various roads of reasoning this out, and prefer to just skip to 'it's a miracle' we are still left with the very real possibility that you nor I know just exactly what miraculous thing God did to 'conceive Jesus in Mary's womb. You can declare that half of His chromosomal complement comes from Mary, but there is exactly zero Biblical evidence for this ... and we do have a mountain of biological data to suggest other possibilities and still not toss away the reality that God performed a miraculous event to conceive Jesus in Mary's womb.
The question I would ask of you then is upon which chromosome is the original sin of Adam carried?
This is the problem. The Roman Catholics and the Protestants believe that ‘original sin’ is a stain carried in the nature. This is what creates the ‘need’ for the immaculate conception dogma.
I don’t believe that is true. I believe the human nature is ‘broken’ not guilty and the Christ accepted our broken nature and fixed it.
In the same way God made adam from the clay in Genesis he made the new adam from the Theotokos. In the same way He made Eve from the Old Adam, he made the new Adam from the daughter of the old Eve.
Chromosomes, blood, etc. are irrelevant. The biblical concept is ‘the life’ and it is the life of the children of the first Adam that the Lord accepted and redeemed.