Like a Virgin, Prasad, Aarathi [free children's ebooks pdf .TXT] 📗

later stages of life. For instance, the father’s genes have a say in whether or not a child develops disorders related to food, possibly including obesity. Here, once again, we see the battle between the father’s DNA and the mother’s body.

This is because those eighty genes that are subject to imprinting have an important say in the development of our brains. Those genes that are silenced when inherited from the mother but expressed when inherited from the father inhibit our overall brain size; they contribute to the development of the hypothalamus – the impulse centre that makes us crave food. In contrast, the imprinted genes that are expressed when inherited from the mother contribute to the cortex, the so-called grey matter of higher mental functions; the striatum, which is involved in decision-making and risk-taking; and the hippocampus, the brain’s memory centre. Recent molecular analysis has shown that among people who carry defects or mutations in genes that are supposed to be imprinted, there is a surprisingly large incidence of cognitive, behavioural, neurological, and psychiatric conditions. These include autism, bipolar affective disorder, epilepsy, schizophrenia, and Tourette’s syndrome.

This sex divide in the role of imprinted genes on the brain is curious, because what happens in the hypothalamus is also believed to influence maternal behaviour. Studies in mice have shown that mothers will neglect their offspring if the PEG1 gene (paternally expressed gene 1) is removed from their fathers so that they are not able to inherit it. A related gene, called PEG3, increases maternal care, too, and also regulates male sexual behaviour – meaning it ensures its own preservation. If a male mouse does not have the PEG3 gene, then, no matter how much sexual experience it gains, it is unable to improve its reproductive effectiveness; for example, no amount of experience will make the mouse better able to recognize the odours that female mice secrete when they are ready to mate. It seems that a father can even directly influence how his daughter will behave towards her own children, through imprinted genes alone.

For mice and men (and women), evolution has pitched mother against father, father against mother, mother against child, and child against mother – our genetic sources and our genetic creations are all battling for control. The outcome of these long-ago skirmishes is a treaty written in DNA: neither a mother nor a father may use all the genes at their disposal, but both will have a genetic and a chemical voice that will continue whispering into the brains of their children – all the way into adulthood. Neither sex can do without the other. At least, that is, while we are still constrained by the body.

But what comes next? Will those restrictions still hold when eggs and sperm and foetuses and wombs are no longer tied to biological packages of human anatomy? Because, if the past centuries of discovery show anything, it is that once science stumbles upon an obstacle, the next step is to tear that obstacle to bits, find out how it works, and then see if we might get rid of it altogether.

PART II

A NEW WAY OF MAKING BABIES

All our science is just a cookery book, with an orthodox theory of cooking that nobody’s allowed to question, and a list of recipes thatmustn’t be added to except by special permission from the head cook.

Aldous Huxley

6

OUT OF THE TEST TUBE

If every physical and chemical invention is a blasphemy, every biological invention is a perversion... And all this of course applies much more stronglyto the sexual act.

J. B. S. Haldane, Daedalus, 1923

On 27 July 1978, the front page of the London Evening News carried a nearly life-sized photograph of a beautiful infant, a mere eighteen hours old. She was wide-eyed and swaddled all in white, a perfect specimen of just-born humanity, and she was pictured below the headline – superbabe – that announced her birth.

Louise Joy Brown was no ordinary newborn, but ‘the world’s first test-tube arrival’, a child widely celebrated as a miracle of science. As her middle name testified, Louise was an even greater miracle to her infertile mother, thirty-year-old Lesley Brown, whose grossly distorted and persistently blocked Fallopian tubes had made it impossible for her to become pregnant over the course of nine arduous and depressing years. Louise was the first child to be born through in vitro fertilization, or IVF.

Medical science had been wrestling with infertility for quite some time. But because the subject has been (until very recently) shrouded in secrecy, it is almost impossible to say with any accuracy when artificial insemination in humans was first attempted by doctors. ‘Historically, artificial insemination is one of those rare medical entities which cannot be traced back to Hippocrates,’ wrote one American obstetrician back in 1943. Yet, we can trace the practice to at least the middle of the fifteenth century, when a French doctor called de Villeneuve performed artificial insemination for King Henry IV of Castile and his second wife, Joan of Portugal. The king was rather unkindly nicknamed ‘The Impotent’ – and although local prostitutes confessed to a priest that their monarch was perfectly sexually capable, close examination confirmed that he could not, indeed, get an erection. Artificial insemination, however, was not successful. De Villeneuve could not have known that King Henry was probably living with a pituitary tumour or a condition known as hypogonadism, either of which would have rendered him completely sterile. So whatever ejaculate he could supply to his doctor contained little or no sperm. Even if de Villeneuve had managed to introduce the royal semen into Joan’s womb, pregnancy would have been near impossible. Fortuitously, his wife took matters into her own hands and bore three children by natural