Like a Virgin by Prasad, Aarathi (recommended reading txt) 📕

The most likely explanation was that Jane’s own mother had conceived non-identical twin girls, who would have been no more alike genetically than two siblings conceived at separate times. At an early stage of the pregnancy, however, these twin embryos had fused, to form a single embryo. Because Jane’s blood cells presumably carried DNA from one twin, and her ovaries and the majority of her eggs carried DNA from the other, a quick DNA test threw out the result that she was not the mother of two of her own children. Speaking in terms of DNA only, Jane’s unborn twin was, in fact, the mother.

Yet, in one very significant way, FD was not like Jane at all.

Getting pregnant in the normal way is a hit-or-miss process; a couple has only around an eighteen percent chance that the man’s sperm will penetrate the woman’s egg at her peak period of fertility, assuming, of course, that they are having unprotected sex. Then, there are the odds that a fertilized egg will transform into an embryo, and make it to full term. Jane’s foetal life had been very rare – two different eggs developing into two different embryos and then fusing together. Which makes the way in which FD began life all the more incredible. FD had originated from only one egg. What is more, that egg had broken the laws of nature and developed into an embryo without waiting to be fertilized. His blood with its two X chromosomes was the product of parthenogenesis.

How tiny is the likelihood of each single event in the sequence of events that brought FD to life! First, one of his mother’s eggs – the egg that would become him – was activated by some hormonal trigger, despite there being no sperm around to do the job. The activated egg then began dividing, the first steps towards becoming FD. The only DNA in FD’s embryo at that point was from his mother. Next, rather ‘miraculously’, along came a sperm – a single sperm, as far as the scientists can tell – from his father. It should have arrived too late to have any effect, since normally after an egg is activated, a cascade of chemical signals tells the egg’s outer layer to harden, making it impossible for ‘follow-on’ sperm to penetrate the egg and mess things up. An egg that accepts more than one sperm will form an embryo with too much DNA, and such embryos are normally destined for early termination – a miscarriage.

If FD was the product of parthenogenesis, couldn’t Monica Jones have been a product of parthenogenesis, too? Unfortunately, scientists will probably never be able to answer definitively the question of Monica’s maternity and paternity; they just don’t have the information necessary to figure it out – the DNA of her mother’s parents. But there might be alternative circumstances in which a woman might give birth to a child, apparently unaided.

Take, for instance, the best-known story of a virgin birth and consider how in the world such a miracle could have been effected – biologically rather than divinely speaking. In the third century ce, an influential Church father named Origen worked to promote belief in the virginity of Mary, mother of Jesus, in what sounds at times like evolutionary terms, to the modern ear. The evangelist wrote:

For it is ascertained that there is a certain female animal which has no intercourse with the male (as writers on animals say is the case with vultures), and that this animal, without sexual intercourse, preserves the succession of the race. What incredibility, therefore, is there in supposing that, if God wished to send a divine teacher to the human race, He caused Him to be born in some manner different from the common!

Origen argued that reproduction without a mortal man was very uncommon indeed; for instance, he dismissed the legend of his countryman Plato’s immaculate conception, as ‘veritable fables’ that did not demand such creative innovation. But what rare biology might have been involved in producing Jesus (or for that matter, FD)? To answer that question, an emeritus professor of genetics at University College London, Sam Berry, has worked out the biological possibilities for how Mary could have given birth to a son, while still remaining a virgin. Beyond the issue of activating the egg to develop into an embryo without a human sperm, there is another problem: the fact that Jesus was not Mary’s daughter.

A woman alone should never be able to provide the genes needed to make a son. The Y chromosome, which carries the genes that dictate maleness, are normally only carried by men, so are passed on through a father. So if Mary had given birth to God’s divine daughter, the biology would make sense – she would have been able to provide all of the DNA, with the supernatural power activating the egg in some way. But Jesus was, as we know, God’s only son.

To produce a son via virgin birth, Berry suggests that Mary may have suffered from one of the several chromosome abnormalities that cause testicular feminization, a condition which affects around one in thirteen thousand people. While women with testicular feminization have a Y chromosome, they ‘present’ as a girl at birth – with a vagina and no testes or penis. And throughout life, they appear to develop along female lines, growing breasts, for instance. Internally, however, their bodies tell a different story. The vagina is quite short, and leads to nowhere – neither to womb nor ovaries – and hidden away in the abdomen, there is a set of testes. Normally, testes make testosterone, the hormone that masculinizes the growing embryo and child, so that he develops the external genitals and other sexual characteristics of a typical male – such