Tomorrow's People

by Susan Greenfield

  So, in the end, what does the future hold? Once cloning techniques are perfected, and once adoption-type legislative precautions are in place, there will be no clear-cut grounds for preventing human cloning for infertile or same-sex couples, other than a possible diminution in uniqueness, as currently shown by studies of identical twins. Such people, desperate for progeny, would, I'm sure, have a very strong reply to those who simply dismiss the prospect because there is ‘no reason’ to clone humans and state that such couples ‘can be helped in other ways’. It is getting easier, in the UK at least, for same-sex couples to adopt a child; even so, for many people, reproductive freedom is a personal liberty. And surely the critical issue, for adoption and cloning alike, is that the parents, heterosexual, homosexual or solitary celibate, prioritize the welfare and love of the child, take full financial responsibility for their actions, and do no harm to society at large or to the individual who is the child ‘made’ by cloning. A further application, resurrection cloning, whereby a dying relative is cloned, again, need not be intrinsically repugnant; once we grasp the fact that a clone really is not a simulacrum in all mental and physical traits of the original, then the horror, and along with it perhaps even the appeal, diminishes.

  On a more realistic and practical level, leaving aside the need to develop cloning technology further before it could be used, there are other basic considerations. A surrogate mother must be found, if the commissioning mother is unable to carry a child, and more fundamental still is identification of a source of a ready supply of eggs to act as host to the alien, adult DNA which will be introduced to form the genome of the clone. Eggs must be available that are abundant and cheap. Payment of donors in the UK, as of surrogate mothers, is forbidden, but in the USA women can charge between $3,000 and $6,000 dollars for ten eggs. As it stands, this is not a technique that could easily become commonplace, say on the National Health Service, on financial grounds alone. For that very reason the problem may not be one of practical implementation but rather of creating yet further social divisiveness.

  In any case, there is a good reason not to panic about cloning: as a solution for infertility it could become obsolete within this century. Some think that in the not too distant future it will be possible to take a cell from anywhere in the body, and deprive it of half its chromosome content – to become just like a sperm or an egg. Once gametes (sperm and eggs, and their equivalent in genetic terms) can be made in this way, from any cell, irrespective of the age or health or sex of the cell donor, then anyone would be able to have a baby with anyone else.

  So, for example, a post-menopausal woman would still be able to have a baby, perhaps hiring someone as a surrogate womb if she herself was physically unfit. The father could be a matter of personal choice, using the usual range of criteria, or an anonymous donor from a sperm bank. However, Robin Baker goes so far as to predict a ‘Gamete Marketing Board’ whereby the consumer could select the DNA of football stars, or university professors or film stars. Irrespective of her sexual orientation, our heroine might even choose another woman, who could either supply the egg or, if she too was infertile, provide half the genetic material from a cell elsewhere in her body.

  Similarly, male homosexual couples would be able to have a baby that is biologically all theirs. As for cloning, a donor egg would be needed, subsequently evacuated of all its original DNA. Half the genetic material would then be supplied by the haploid nucleus derived from any cell in the body of one of the couple, but depleted of half its DNA, whilst the other half would originate from the second man's sperm or indeed, if he were infertile, from a haploid nucleus taken from a cell elsewhere in his body. The baby would then be carried in a surrogate.

  If such a prospect came about, along with the increase in active, elderly people, then future generations would be living in a society of parents of all ages. Indeed, it might become normal to have a child late in life, once one's career was over and there was more time and money to devote to the offspring. Children would grow up with the huge benefit of full-time parents, albeit elderly ones. But this new type of mothers and fathers would not be the equivalent of present-day grandparents; if they were physically much fitter, more mentally agile and more healthy than their present-day counterparts – as we have seen they may well be – then their age should not be a factor. However, there is a potential problem, not for the parent but for the child: whereas newborn cells divide some eighty to ninety times those from elderly organisms will do so only twenty to thirty times. The older the cell the shorter the telomere – the cap on chromosomes the loss of which allows chromosomes to stick to each other, resulting in eventual death of the cell.

  It turns out that the first cloned mammal, the sheep Dolly, had shorter telomeres than usual. She died in 2003, having lived only half the usual lifespan of a sheep. But there remains some debate as to how much shortened telomeres influence longevity – and some recent data suggests that cells from cloned cattle actually seem younger than those from their conventionally conceived peers! Regardless of this, however, in April 2002 Ian Wilmut, co-creator of Dolly, reported that all cloned animals up to that date had suffered from genetic defects, including gigantism in cloned sheep and cattle and heart defects in pigs. As Wilmut warns, this research suggests a cloned human would be at huge risk of genetic defects – at least at present. If using DNA from somatic adult cells (not sperm or egg cells) means that the offspring from which they are produced have ‘elderly’ DNA, then their rate of ageing would be faster than that of those born of germ cells, an original sperm and egg. Then again, this situation could be offset by improved treatments for delaying cell-ageing, including treatment with the enzyme telomerase which will keep the telomeres long and healthy; in addition, everyone could be encouraged to freeze their eggs and sperm when in their biological prime.

  A further complication, if reproduction and sex become increasingly distinct, will be the rise of surrogate mothers. A surrogate carries the biological child of the two commissioning parents, if the real mother is unable to carry the baby in her own womb; alternatively she may act as the genetic mother as well, following artificial insemination of the commissioning man's sperm, if the commissioning mother is infertile. There may be an emotional tussle if the surrogate mother does not wish, in the end, to surrender the baby. And there is arguably a potential psychological problem for a woman raising a child with whom she has no genetic allegiance, but the father does. Surrogacy in this form, then, may be less than ideal; in the future two further technical developments may offer alternatives, though not without the ‘yuck factor’ that often accompanies new technical discoveries and concepts.

  One possibility, in cases where the baby is the genetic product of both commissioning parents, might be for a primate species other than human to act as surrogate. Already xenotransplantation, whereby a transplanted pig heart, for example, could save the life of an otherwise terminally ill coronary patient, is a real prospect; a surrogate womb is surely not that different, when it comes to either ethics or rationale. And if animals can help us out not just with heart problems but reproductive ones too, zoologist Robin Baker predicts, non-human surrogates could help men also – a man who had lost his testes, say, during cancer treatment. It would be possible to inject that man's stem cells, from which his sperm would be made, into the testes of several rats. The surrogate testes would then start to produce both rat and human sperm. These testes could then be grafted into the human scrotum, so that the man would be using surrogate rat testicular machinery to ejaculate his own sperm in the usual way. The only complication would be that he would be producing rat as well as human sperm, which may be a ‘yuck factor’ both for him and his partner. However, aside from an additional problem of possible allergic reaction to rat sperm, there would be no harm in the insemination of a human with rat sperm; in the unlikely event of it entering a human egg, that egg would die. By comparison to this scenario, or indeed to the heart xenotransplant, a surrogate primate womb seems perhaps more ac
ceptable. Indeed the rat testes, or the pig heart, would be in your body for the rest of your life, whereas your offspring would be in an alien body for a mere nine months. Once it was born, no one would know any difference.

  The other possibility would be to dispense with the squalor of biology altogether and use artificial wombs. This idea was actually first mooted by J. B. S. Haldane in 1923, in his prophetic paper Daedalus, or, Science and the Future; a little later the notion was taken up by Huxley to form part of his Brave New World, in which babies are no longer born ‘viviparously’, from living parents. Scientists first explored this idea in 1969, when they managed to keep a sheep foetus alive for two days. More recently, in Japan in 1992 a goat foetus survived and was delivered after seventeen days in an artificial womb; but it was already 120 days old, three-quarters of the way to full term, before it was put in the artificial environment. The difficulty with developing an effective artificial womb that could sustain a human body from conception to full term is in simulating the highly complex and sophisticated workings of the placenta, which absorbs the goodness from the mother's blood, and dispatches waste.

  A halfway measure might be to create an artificial womb lining, in which embryonic cells could be stimulated to grow, by means of appropriate combinations of drugs and hormones. The whole ensemble could then be transplanted into the mother. Such a treatment might be helpful to infertile women, and they would still undergo a conventional pregnancy. Assuming however that by the middle of this century, say, the huge technical hurdles are overcome, then artificial wombs might offer an attractive and ethical alternative to pregnancy.

  One advantage would be that both parents could watch the child grow day by day through glass walls of the womb or via a computer-camera link; undoubtedly this would be a fascinating experience, at the very least, and the father, for the first time, would feel as involved and equally bonded to the child during the pregnancy as the mother. Now imagine the addition of augmented reality systems: different stages in the baby's development, along with changing statistics – the approximate number of brain cells, weight, heartbeat and blood pressure – all appear on the display. Obviously, with such a system, samples of amniotic fluid could be taken every day and would offer the paediatrician a much more accurate means of monitoring that all was well, and forewarn of any potential complications.

  Aside from all the medical advantages for the well-being of the foetus, an arguable bonus would be that women could be increasingly active in the workplace if their babies were gestated in artificial wombs; they would also avoid the tribulations of normal pregnancy, with all the attendant problems of morning sickness, weight gain, fatigue, stretch marks, varicose veins, insomnia and other discomforts, as well as the increased risk of hypertension and diabetes. Of course, there is also the alarming prospect that different additives and supplements could easily be added to the equivalent of the amniotic fluid to create appropriately able or servile future citizens, as in Huxley's Central London Hatchery. But then, it is important to remember that such engineering could occur before implantation in any type of womb, artificial, surrogate or ‘natural’. However, any queasiness – and there may be much justified objection to artificial wombs – should not include the potential for external intervention. Already there is no technical divide between screening embryos consisting of some eight cells after IVF, for elimination because of an unwanted trait, and screening them for implantation because of a desired characteristic, such as tissue-matching with a sick sibling. Let's compound the dilemma still further by actually changing or deleting a rogue gene.

  We have seen earlier that the problem with gene therapy in adults is the difficulty of accessing the relevant malfunctioning cells of the body; these cells number trillions and are already realizing their malfunctioning genetic destiny. But if our intervention occurred at the eight-cell embryo stage, or even at the sperm or egg (germ cells) stage prior to IVF, then that problem would be solved. Every cell in the body there-after (somatic cells) would contain the desired genetic profile. This germ-line engineering is already well established as a technique in research animals; an appropriate gene is changed so that the animal, usually a mouse, will then have a particular genetic defect – a transgenic model of a condition such as Alzheimer's disease or Huntington's Chorea, as used in the experiment exploring the importance of the environment on genetic destiny described earlier in this chapter. Similarly, germ-line engineering has the awesome potential of changing the human gene pool for ever. Not just the individual that grew out of the embryo but also their children in every generation to come would have been, effectively, genetically modified. This is why the technique is currently unconditionally illegal everywhere in the world.

  It is but one small step, and far easier than engineering the 100 trillion cells in the adult body, to manipulate the DNA of those embryonic cells, or better still of the germinal cells, the sperm and egg from which they were produced. However, the problem with germ-line engineering has not only been that, unlike after somatic therapy, the change would be passed on for ever from one generation to the next but also that there could be considerable, and undesirable, interaction between the engineered genes and other genes on the chromosome.

  But now both those problems might be about to evaporate. Over the last few years Andy Choo, from the Murdoch Children's Research Institute in Melbourne, and a separate team, John Harrington and Huntington Willard from Case Western Reserve University, have each pioneered auxiliary artificial chromosomes. If the technology lives up to its promise – and it already appears to work in mice – then far more genetic material could be introduced into a cell, with far less interference and with far more accuracy and ease of manipulation. And even the problem of engineering immortality could be overcome, by a pioneering new technology that could reverse the change from one generation to the next. The new gene would be combined with the gene for an enzyme (CRE) that could effectively obliterate it. This killer gene could in turn be switched off so that it was active only in sex cells, and even then only when a particular drug was taken. So, you could take a drug that eliminated exclusively from your sex cells the artificial chromosome with its germ-line engineered gene. You would still have the engineered trait, but your ensuing children would not. This reversibility would give the flexibility that has been the chief deterrent against legitimizing germ-line engineering, whilst at the same time allowing for much more effective gene therapy against gene-related diseases. Indeed, Gregory Stock foresees that the ability to change genes with each generation could be a positive advantage, analogous almost to the upgrading of software today:

  Imagine that a future father gives his baby daughter chromosome 47, version 2.0, a top-of-the-line model with a dozen therapeutic gene modules. By the time she grows up and has a child of her own, she finds version 2.0 downright primitive. Her three-gene anticancer module pales beside the eight-gene cluster of the new version 5.9, which better regulates gene expression, targets additional cancers, and has fewer side effects. The anti-obesity module is pretty much the same in both versions, but 5.9 features a whopping nineteen antivirus modules instead of the four she has and an anti-aging module that can maintain juvenile hormone levels for an extra decade and retain immune function longer too. The daughter may be too sensible to opt for some of the more experimental modules for her son, but she cannot imagine giving him her antique chromosome and forcing him to take the drugs she uses to compensate for its shortcomings. As far as reverting to the pre-therapy, natural state of 23 chromosome pairs, well, only Luddites would do that to their kids.

  So the door would seem to be open for prospective parents to eliminate single genes from a foetus – the ‘designer child’ – or to survey a portfolio of desirable genes in the hope of cherry-picking desirable traits – the ‘virtual child’. Sinister though such eugenics might appear, Gregory Stock defends the idea, arguing that different people would value different traits in their offspring, thereby preserving diversity in society; at the same tim
e if, say, the IQ of everyone was enhanced, then that would ensure that the playing field was actually more level than in our current very divergent society, not less. Moreover, assuming that germ-line engineering were safe and free of side effects, what parents would not want to help their children as best they could? How would such a strategy differ from paying for extra tuition, or sending them to the best school you can afford? The values and the much-hoped-for outcome would be the same, only the method would differ.

  Two big problems that cannot be argued away easily, however, and which are not tractable to pure technology, are first the misapprehension about what gene manipulation might do, especially with respect to mental functions, and secondly an effective speciation between the haves and have-nots worldwide. The idea of designer and virtual children is predicated on a clear understanding of the relation between gene and mental trait. Yet we have seen that such a link is far from obvious. True, we can tackle an aberrant gene in the hope of alleviating a disorder, but it by no means follows that by adding a gene we can enhance a normal function; even if we could, we might well change a host of other brain functions as well, as many different types of proteins were made, all interacting in the individual brain in ways that could not have been predicted.