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Identically Different

Why You Can Change Your Genes

Tim Spector



Epigenesis in action. Adult Dapnia, the water flea, have variety of defences against predators, including helmets and spiny tails - some have both, some have one, some have none. Yet they are all genetically identical. Put a young flea in water with no odours of predators and they will develop no defences. But if you put it in a tank with traces of a nasty fish, it will develop a spine and helmet. Put the babies of these two in opposite tanks, and they will develop the defences of their mothers, rather than what needed for the current environment. The effects last a few generations then fades.

Similar results in chickens and mice. By feeding mice a methylation-inducing chemical in it's food, can switch off normal fur colouring, so that melanin comes through and mouse develops brown fur.

We inherit two copies (alleles) of each gene - one from each parent. In most animals there is a battle between the father's genes and the mother's. The father's genes are trying to increase the size of the fetus to increase it's survival chances. The mother is trying to conserve her resources to live long enough to have more children. Evo says we have descended from mothers who won that battle, since she will have more kids. Humans have at least 50 of these development genes, in which the female completely suppresses the male allele.

Our views as to the origins of behaviour have always been heavily influenced by current social attitudes. Traditional religious explanation that sickness and bad behaviour due to sin. Then when early twin studies showed correlation for diseases and for choices, backlash from those who wanted idea that we all start out equal.

Longitudinal studies showed conscientiousness only factor which predicted longevity. Extreme optimists died earlier, partly because took more risks and partly because less careful in getting medical help when needed. Vietnam POW's who were optimistic that would be freed by Xmas, then by Easter, then by Thanksgiving, gave up and died of broken heart when disappointed.

Many gene studies show variations along lines that you may have a predisposition for depression, or alcoholism etc, but only kicks in if have to face a major stress event.

A whole series of books pointing out that it is not talent which predicts success, but hard work.
Malcolm Gladwell.... Outliers
Matthew Sayed .... Bounce: The Science of Success
Geoff Colvin .... Talent Is Overrated
David Shenk ...The Genius In All Of Us
All based on the work of Anders Ericcson, a Florida psychologist.

Ericcson compared thousands of experts with novices in fields from music to sports, medicine and law enforcement. He found no evidence for innate ability. Experts perceive more information, and afterwards, remember their thought processes more clearly. But anybody with the right kind of practice can dramatically improve their performance. The key is to focus on the areas you are weakest. Famously taught a student to become a memory expert, after 250 hours of training, an hour a day for two years. Most people struggle to rem an 8 figure telephone number - the subject could memorise over 80 digits.

1987 Hungarian educational psychologist Lazlo predicted that he could make his children chess champions (he advertised for a woman who would marry him and accept this goal). When his first daughter three years old he started playing chess with her, getting her hooked with fun chess games. Did same with her two later sisters. By the time they were 14 they had each done their 10,000 hours, and all became chess grandmasters (one of them the youngest grandmaster ever). When critics suggested that the successes were partly due to heredity (he was a top class player himself), he offered to adopt 3 more children and repeat the exercise. Sadly his wife was tired of chess and children, and he was overruled.

The Kenyans who dominated middle distance running in the 1970's didn't share genes. What they did have in common was that they all grew up at high altitude (and so had more red blood cells and better oxygen transport to the muscles), and they all ran to school and back every day, so that they had clocked up 10,000 hours of running. (American bumper sticker: "Help save our runners - donate a school bus to Kenya".) But the children of the champs did not carry on the tradition. Perhaps the fame and prosperity took away the drive; perhaps they didn't have to run to school any more.

One of the surprising results of the last British census was that 390,000 citizens identified themselves as Jedi, and third largest religious group in Britain.

Recent modern trend for women to wax pubic hair. Studies by highly dedicated researchers who looked at every single Playboy centerfold from 1953 onwards (647 of them) confirmed that the trend to 'hairless Barbie' look only began in 2000. Suggest that due to the porn industry, which felt it made women look sleeker, and in turn made other women think the look was a lot more commonly accepted than it really was.

NZ case where 16 yo girl complained to police that she's been raped after a night out in a bar. Police took semen sample and traced the guy. But he had an identical twin brother who was also at the bar that night, and they both claimed they were so drunk they couldn't remember what happened. The forensic lab couldn't tell the difference (they were identical on 13 major markers generally used to distinguish). Author said that he offered to separate them on the basis of different methylation, but because the technique had not been rigorously tested and accepted, the evidence probably would not have stood up in court.

(London Times article)

Nicky and Louise are 30-year-old identical twins. They are attractive, competent women and, as you would expect, have a lot in common - taste in food, drink and clothes, and a commitment to exercise. They avoid dangerous sports, cigarettes, drugs, and gambling. As identical twins have exactly the same genes, there you have it, proof positive, it's all in the genes.

Except it isn't. Nicky has had five men in her life, Louise 25. Even though they like the same kind of men and both enjoy sex and have orgasms, their attitudes are utterly different. Aged 15, they discovered that their father had kept a secret mistress for years. Nicky took it badly; Louise didn't, and, at that point, their sexual trajectories diverged.

But why? The short answer is that identical twins aren't identical and our genes are not our destiny. Tim Spector is a professor working in genetic epidemiology at King's College, London. He made the headlines and outraged many 'sex counsellors' when he announced in 2009 that the G-spot (a zone of special erotic sensitivity in women)did not exist.

He also used to think genes were the heart of the matter. "Until three years ago," he writes, "I was one of the many scientists who took the genecentric view of the universe for granted. But I had a nagging doubt that we were missing something."

Spector is not alone in experiencing a Damascene conversion from gene-centrism, but with this eminently readable book he is the first successfully to explain the issue to the general reader. In 1993 he started the UK Twins Registry of 11,000 twins, which is now one of the best databases of its kind in the world. Identical twins are one of the gold standards of genetic research; they have the same genomes, therefore any variations or similarities in them provide evidence of the influence of the genes. Spector's doubts emerged as the variations revealed by his database became ever more apparent.

These variations need not be minor, they may be a matter of life and death. Twins Peter and Nigel, for instance, were ready to celebrate their 42nd birthday together when Peter hanged himself. Depression ran in the family but, although identical, only one of the pair seemed to have inherited the trait. Even conjoined twins such as Ladan and Laleh in Iran exhibited striking differences. Laleh liked computer games, Ladan liked praying; Ladan was left-handed, Laleh right-handed. They died in the operation to separate them in 2003. Doubtless, if they had lived apart, they would have diverged even further. The point here is that identical twins do not prove the power of the gene, they define its limitations.

Now, full disclosure - I have a dog in this fight. In the 1990s, while writing a book on genetics, I became baffled by the arguments of the gene-centrists. Following Richard Dawkins, who insisted we were lumbering robots operated by our genes, the gene-centrists claimed that our genomes did almost everything and that whatever remained could be explained by the 'environment', an entity that remained undefined. This position was riddled with unfounded assumptions and contradictions but, whenever I pointed this out, the scientists merely looked at me pityingly. Anyway, just to say, thanks, Spector, for backing me up.

The defeat of the gene-centrists began with the over-hyped publication of the human genome in 2000. This was, it was claimed, "the book of life" - it isn't _ and was to be the prelude to a revolution in medicine _ so far, no. The first sign there was something wrong was the revelation that we have only about 23,000 genes, half as many as a tomato, and only a quarter as many as, in our vanity, we thought we had. The second sign was that the gene-centrists' belief in the simple link between genotype and phenotype (organism) was naive; vast complexity was the harsh (but, for me, consoling) reality.

One genetic fundamentalist claim after another collapsed - there is no gene for homosexuality, none for alcoholism and so on. It is probably true to say that the phrase 'gene for' is usually meaningless. This is partly because many genes are involved in almost any trait, but, more important, it is because (as Spector surmised) there was something missing.

What was missing is now called epigenetics, a concept whose importance can scarcely be overstated. The gene-centric view was that the gene produced a protein that went on to build an organism. In fact, we now know not only that some genes can produce several proteins, but also that this mechanism can be turned on and off by processes of which, not long ago, we knew nothing. The gene, in other words, is not the last word and may not even be the first. It is certainly not in complete control of anything.

The implications are staggering. The first is that twins may not be identical because these processes (the most common is called methylation) could have happened to them in the womb. Second, the sins of the grandparents can be visited upon the grandchildren. Spector has cases of one generation's starving and binge-eating during postwar austerity resulting in obesity two generations later. In other words, what you do in life may affect the genomes of your offspring.

This book concludes with a list of four genetic dogmas that have been overthrown: genes are not our essence; our genetic inheritance can be changed; environmental events can be 'remembered' by cells; and what happens in your life can affect later generations. Or, to put it bluntly, almost everything you've been told about genetics is wrong.

The list also, potentially, settles the old, stale and often irrational argument about nature v nurture. What epigenetics demonstrates is not a simple division between humans and their environment (the underpinning of much of the illogic spouted by the scientists I met in the 1990s), but rather a flow of indecipherably complex interactions, a ballet of cells that, in some ways, matches the flowing, dancing world of particles and forces discovered by the physicists beneath the surface of matter.

This is not simply a book of ideas, it is also a book of stories, most astounding, many heartbreaking. Flo and Kay, for example, were an incredibly rare case of "idiot savant", identical twins who found peace in the American television quiz show Pyramid. When it ended, they found further consolation in the idea of being buried with memorabilia of the show's host Dick Clark. There are twin sisters, one of whom has frequent orgasms and one who didn't have one until she was 42. There is a twin who conspires, unsuccessfully, to have her identical twin murdered. Most alarmingly, there is the story of a substance in almost all plastic that may epigenetically alter our genomes. If proved, that, I imagine, will make the euro meltdown look like a very small disaster indeed.

Spector will get you through many dinner parties. But, much more importantly, he will show how a certain kind of scientific fundamentalism collapsed under the burden of its inability to explain the world as it is - complex, flowing, changing - rather than as they would like it to be - simple and clear. Read him.

































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