Nurturing the nature of a clone

An American woman's cloning of her deceased dog may be an indicator of the commercial viability of cloning.

Bernann McKinney holds one of five pit bull puppies cloned by a Korean biotech firm from her deceased dog, Booger.
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Bernann McKinney was clearly overjoyed about being reunited with her beloved pit bull terrier Booger last week - or, to be precise, five of him.  Ms McKinney of California had paid USD 50,000 (Dh184,000) to a biotech company in South Korea to create genetic clones of her pet dog from cells taken from Booger before he died, and last week she was presented with five identical puppy versions of him. (British readers will remember Ms McKinney as Joyce McKinney who in the 1970s kidnapped a Mormon missionary in England and later claimed that she was so in love with him that she would "ski naked down Mt Everest with a carnation up my nose if he asked me to".

Scientifically, there's nothing new in all this. The first cloned organism, a tadpole, was created as long ago as 1952, while the famous Dolly the cloned sheep, which was supposed to open the way to cloning from adult cells, was born more than a decade ago. Even pet cloning has been done before, the first- a cat named "CC" - being born in 2001.  The real significance of the Booger story lies in the claim by RNL Bio, the company that created the puppies, that it expects to be able to clone up to 300 dogs next year for anyone willing to pay. And that's just the start, according to chief executive Ra Jeong-Chan, who reportedly has plans to set up an office in Dubai to clone champion camels and horses.

Taken at face value, this suggests cloning really has turned the corner, and is finally about to become commercially viable. After the media hoopla that surrounded the birth of Dolly and other cloned animals, one could be forgiven for being surprised that this hadn't happened years ago. But the hype has obscured the fact that the success rate of the cloning process has been disappointingly - some would say, repulsively - low.  Creating Dolly required more than 270 sheep eggs, which created just 29 embryos, and of those implanted into sheep, 95 per cent ended in miscarriages, with only Dolly surviving to adulthood.

Scientists have been searching for more effective ways of creating clones ever since, with research teams in South Korea and Japan claiming to have made important progress. Judging by the confident forecasts of RNL Bio, such research is now starting to pay off.  So are we about to see the emergence of whole stables of identical racehorses and camels, each carrying the genes of champions? Quite possibly, but anyone thinking of spending a fortune on creating their own stable of unbeatable clones is likely to be bitterly disappointed by the end-results. For despite the oft-repeated claims about the crucial importance of genes "for" various traits, their role is far from decisive.

Arguments over the relative importance of genes and environment - the "nature versus nurture" debate - go back long before anyone even knew what genes were. Most have focused on the role of genes in determining human traits. As long ago as 1690, the English philosopher John Locke claimed human behaviour is entirely the product of experience, each of us entering the world as blank slates. But by the start of the 20th century, the debate had lurched over to the other extreme, and a widespread conviction that many traits were largely if not wholly inherited. The claim was backed by studies of identical twins separated at birth, whose similar traits despite different upbringing was put down to the fact that they have identical genetic blueprints.

Yet for all its apparent scientific rigour, this fails to explain the experience of many parents of identical twins, whose offspring turn out radically different despite having both the same genes and a similar upbringing. This suggests that the nature-nurture split is a false dichotomy, with genes, environment and other factors interacting in complex ways.  After dismissing such evidence as hopelessly anecdotal, scientists have largely caught up with this folk wisdom. Studies of identical twins show that genes are responsible for around 50 per cent of the variation in personalities between individuals.

Simple arithmetic then implies that a hefty 50 per cent must be put down to environmental factors, of which the most obvious is home background and parental influence.  Yet ground-breaking research published in 1995 by the American psychologist Judith Rich Harris showed that parents have virtually no impact on how their children turn out. Studies of children raised in the same family reveal that parental influence accounts for no more than five per cent of the variation in traits between children.

Exactly what accounts for the remaining 45 per cent is something of a mystery. One possibility is the influence of a child's peer group, or what Harris called "group socialisation". This could explain how children from the same two parents and raised in the same family often turn out so differently. Such children may well have different experiences and peer groups outside the home. The implications of all this are clear. When it comes to gauging the likely future performance of anything from humans to horses, genes often count no more than environmental factors. A genetic clone of a champion horse could thus turn out to be no more than a lazy lookalike. Worse still, precisely what environmental factors lead to success are far from clear - and may never be fully understood.

The idea of cloning has long seemed like science fiction. Researchers may have turned the technique into science fact, but most of the claims made for it remain the purest fiction.  Robert Matthews is Visiting Reader in Science at Aston University, Birmingham, England