A quotation from Ahmedi muslim beliefs:
Is a Literal Son of God Possible?
Evidently therefore, literal sonship of God is impossible because a literal son must have half the character of his father and half the character of his mother. So another problem surfaces, the son would be half man and half god. But those who believe in the literal sonship, claim and emphasise that Christ was a perfect man and a perfect god.
If the chromosomes were half the required number then we are not left with any problem, no child would be born anyway. Suppose it did happen, that child would only be half a man. Not to mention the missing twenty-three full chromosomes, even a single defective gene within one chromosome can play havoc with a child born with such a congenital defect. He could be blind, limbless, deaf and dumb. The dangers attendant to such a mishap are unlimited. One should be realistic; it is impossible to conceive God as possessing any chromosomes, human or otherwise.
Therefore, with the personal physical contribution of God having been ruled out, if a son were born to Mary with only the human character bearing genes possessed by her ovum, whatever the outcome, he would certainly not be the Son of God. At best you can describe that freak of nature as half a man and no more. If the reproductive organs of Mary were like any other female and still the ovum were to fertilize somehow by itself, the maximum one can expect is the creation of something with only half the human characters. It is abominable to call that something the Son of God.
So how was Christ born? We understand that research on the subject of single mother birth without the participation of a male is being carried out in many advanced countries of the world. But so far human knowledge is only at a stage where scientific research has not yet advanced to such a level where positive irrefutable evidence of virgin births in human beings can be produced. However, all sorts of possibilities remain open.
At lower orders of life two phenomena are scientifically well established: Parthenogenesis and Hermaphroditism. As such, the miraculous birth of Jesus, to Mary, can be understood to belong to some similar natural but very rare phenomenon, the peripheries of which are not yet fully fathomed by man.
Here follow brief descriptions of the phenomena of Parthenogenesis and Hermaphroditism. Readers interested in a more scientific treatment of the subject matter, based upon current understanding, may refer to Appendix II.
Parthenogenesis
This is the asexual development of a female ovum into an individual, without the aid of a male agent. It is observed among many lower forms of life such as aphids and also fish. There is also evidence that parthenogenesis can be a successful strategy among lizards living under low and unpredictable rainfall conditions. In laboratory conditions, mice and rabbit embryos have been developed parthenogenetically to a stage equivalent to halfway through pregnancy, but have then been aborted. In recent study, human embryos could be activated occasionally by parthenogenesis using calcium ionophore as a catalyst. Such research raises the prospect that some early human pregnancy losses may have involved the parthenogenetic activation of the embryo.
Hermaphroditism
This term applies when organs of both sexes are present within a single female and the chromosomes show both male and female characters aligned side by side. Laboratory tests have revealed cases such as that of a hermaphrodite rabbit which, at one stage, served several females and sired more than 250 young of both sexes, while at another stage, became pregnant in isolation and gave birth to seven healthy young of both sexes. When autopsied, it showed two functional ovaries and two infertile testes while in a pregnant condition. Recent studies suggest that such a phenomenon is possible, rarely, among humans also.
What are Miracles?
With the possibility of virgin birth being wide open, it does not remain to be all that impossible and unnatural. Where is the need to search for a supernatural explanation of Jesus birth, or even go beyond that to the farthest extreme of believing in the birth of a literal Son of God through a human birth? When all this is observed as a fact of nature, why is it hard to believe that the birth of Jesus Christ was a hidden natural phenomenon, brought about by a special design of God? Something happened in Mary which gave that child a miraculous birth, without a man having touched her. It is the Ahmadiyya Muslim belief that this is exactly what happened. Our case is unshakeable because no scientist can dismiss it as nonsensical or opposed to the known laws of nature. (From the book of Christianity: A Journey from Facts to Fiction)