Genesis of Eden

Genesis Home

Remaking Eden: Cloning and Beyond in a Brave New World
Lee Silver, Avon Books
ISBN 0380974940/0297841351 New Scientist 24 Jan 98

Jon Turney teaches science communication at University College London. He is the author of Frankenstein's Footsteps, to be published later this year by Yale University Press

YOU must have been a beautiful zygote, 'cos ... well, because we made you that way Lee Silver wants to get us all up-to-date on the many new ways we have of making babies, now that sex is unnecessary for human reproduction. Louise Brown, the first test-tube baby, will be 20 this year, and the technology has moved on apace. The range of techniques already proven in humans or animals is impressively wide. Silver covers cloning, of course. But the ability to transfer cell nuclei, which made possible the creation of Dolly the sheep last year, is probably more significant. This and other laboratory tricks mean that virtually any combination of biological, social and genetic parenting is now possible. And, Silver argues, they will all be used. Individual freedom is the American way, and that commitment, along with commercial imperatives, is likely to override any objections to particular applications. Then combine the virtuoso manipulation of embryos with our burgeoning knowledge of human genetics, and we are taking the first steps down a new evolutionary path. Unnatural selection will supplant the much slower natural variety. This vision has been put before us increasingly often during the past few decades, but it is still striking to see the technical details being outlined as (mostly) accomplished facts. Silver, a Princeton biologist, is an excellent guide to the properties of human germ cells, and to the many procedures which prospective parents may now adopt to tip the odds in the reproductive lottery in their offspring's favour. He is also a stimulating guide to the possible consequences of this reproductive revolution, up to a point. His basic assumption-what he sees as the rational as opposed to the emotional view-is that there is nothing special about human reproduction. That being so, there is no reason not to apply any of these technologies, provided there is no obvious harm to the individuals involved. And he is quite inventive in offering scenarios-real or imagined- in which someone feels they benefit enough to make use of every technique described, cloning included. He is also consistently optimistic about individual outcomes. Yet he sees them adding up to a less appealing result, a class society defined by its genes. Eventually, like H. G. Wells's Eloi and Morocks, the gene-rich and gene-poor will become separate species, unable to interbreed.

Working out the consequences of this would require a novelist of Wellsian powers, and Silver does not really try. Instead, he tops and tails the book with a much longer-tenn evolutionary story. It begins with a rather commonplace discussion of the origins of life, and ends with a grand, Dysonesque vision of new, genetically enhanced subspecies of our descendants spreading out through the Galaxy. This piece of technoscientific triumphalism strikes me as an odd frame for the rest of the book. It seems to imply that any attempt to check the development of new reproductive technology and genetics flies in the face of our cosmic destiny. It contributes nothing to the immediate discussion of how to handle the bit-by-bit emergence of control over the make-up of new individuals. And it gives the impression that the enterprise is in the hands of people whose definition of human interests is rather distant from the everyday concerns of real humans. Silver would have served us better by dispensing with the distant past and the far future, and giving us a more sober look at the medium term. He might have persuaded us, as well, that not just new reproductive techniques, but also the social and ethical thinking which should under- pin our use of them, are advancing at speed. As it is, he has written a book that appears intended to reassure or inspire, but which many may find rather alarming.

Us and Them Nell Boyce and Lee Silver New Scientist 9 May 98 36

Your book hinges on the idea that human cloning will become common, guided by market forces and unhindered by legal issues. What led you to this conclusion?

The way Americans have used repro- ductive technologies in the past. For-profit clinics have popped up arolind the country that are willing to offer any kind of services that infertile couples desire, if they are prepared to pay for them. I don't think that cloning will ever be common, in the same way that in vitro fertilisation is not common. But I think it will eventually be accepted and used by a small minority of people in special circumstances.

What about people who say that you should stop cloning with laws?

For example, Britain has banned human cloning since 1990. Human cloning will not harm people if couples use it to have children that they're going to love, and the children are healthy. Many Americans would see laws banning cloning as irrational, and they would try to get around them, in the same way that British women come to America right now to buy human eggs because they can't buy them in Britain. Your most controversial claim is that genetic engineering will ultimately lead to two or more human species that would not be able to interbreed.

Do you really believe this? Why exactly is this going to happen?

Two species could arise in the distant future. I believe this could happen because genetic engineering of embryos is inevitable. I can see ways in which genetic engineering will be made safe and efficient, and there will be a market for it-parents who want to give their children advantages in life. Already, the children of people who have money get advantages, environ- mental advantages-they get better educations, they get better health services, they get computers on their desks to play with. The huge gap between the rich and the poor shows itself in what parents can do for their children. I see that continuing and becoming more pronounced in the future, and extending into the genetic realm. I really do believe that genetic enhancements will accumulate over the years, and that that could inadvertently create humans who could not interbreed.

Do you think parents will deliberately do this to stop their kids sullying the designer genes they have invested in?

One can imagine several different ways in which genetic engineering could be used to initiate speciation on purpose. For example, people could give their children altered sperm-egg binding molecules to prevent them breeding with other people. If we look at the worst examples of ethnic conflict that still plague the Earth, we can surely find examples of people who might do this. If we allow our minds to roam freely, and take off from the worst of human instincts, I don't think we can rule out purposeful speciation.

Would it be such a bad thing, to have multiple human species?

The notion that the upper and the lower classes will become further and further apart until they separate into different species I think would be the most horrible thing that ever happened to humanity. It would give those who were genetically enhanced a rationale for severe discrim- ination against those who were not. The enhanced would treat the unenhanced the same way we treat other species right now. We treat human beings as equals, but we put other highly intelli- gent primates, such as chimpanzees and gorillas, into zcos and cages. With cloning, women will no longer need men to reproduce.

What effect will cloning have on sex as we know it today? Could we end up with only one sex?

I doubt it. Most women I know like having sex with men, and I don't think that will ever change. I think it's important to distinguish the science-fiction scenarios from reality The science-fiction scenarios are little armies of Hitlers running around. But governments are not going to clone people. Governments do not reproduce. People reproduce, and we have to get back to a basic biological fact, which is that people want to have children to raise and to love. This is part of our nature. Governments have never produced children, and I don't think that they ever will.

Is it possible that an all-women society could go off and establish itself on other worlds?

Yes, but I don't see it happening on Earth.

How well do you think scientists are addressing the implications of cloning? Are they being honest with the public?

There are a lot of scientists who are perplexed by the public outcry, but they are afraid of public opinion. They don't want to confront this outcry and say: "You don't know what you're talking about, you're wrong." There could be a backlash that would make it more difficult for them to conduct their research. Whether or not they think human cloning is bad, it is easy to condemn it when a ban would have no effect on their own research.

In your book, you mention that in casual conversation with people at IVF clinics, they said they were anxious to move forward with cloning selected patients. When could this happen?

It's going to take some time. Nobody in their right mind would think about cloning a human being today. I think what those people are doing, quietly, is trying to get cell fusion to work with human oocytes and somatic cells, trying to get the initial embryonic divisions to take place, and that's perfectly legal in the US at this point in time. Ultimately, I think a safe method could be perfected. But they are going to have to wait for many monkeys to be born without birth defects before they attempt it in humans.

Your book makes such extraordinary predictions that some people might accuse you of scaremongering. How do you feel about that?

I'm not suggesting that the most outrageous things are going to happen tomorrow, or even during our lifetime. I'm suggesting that they'll happen if we take the science we know today and just naturally follow it forward. Each individual use of the technology could be justified by the fact that the parents love their children and the children are happy and healthy. It's only when the individual cases are accumulated over many generations that it could have such a dramatic, unintended, long-term effect.

Crunch time: Could cloning rescue pandas from extinction?
New Scientist Jan 98

COWS' egg cells might come to the rescue of endangered species, suggests a study presented this week at a meeting of the International Embryo Transfer Society in Boston. Researchers in Wisconsin reported that they took adult cells from a range of mammalian species and transplanted them into cows' eggs that had been stripped of their own genetic material. They found that the embryos went through the early stages of development. From the moment that cloning hit the headlines last year, researchers speculated that the same technology could help propagate species on the brink of extinction that struggle to breed in captivity. The problem is that the rarer the species, the fewer eggs are available to use as donors for the cloned genetic material. Researchers in Neal First's laboratory at the University of Wisconsin at Madison say the solution may be to use cows' eggs as recipients of nuclei for many species. Tanja Dominko, who initiated the work, says it began as a project to uncover evolutionary differences. She expected cross-species eggs to stop developing or go seriously awry after only one or two cell divisions. Nuclei of one species would be incompatible with the cytoplasm of the eggs of another, she reasoned. But to the team's surprise, embryos with nuclei taken from skin cells from the ears of species as diverse as pigs, rats, sheep and even cynomolgus monkeys developed as far as is possible in the test tube. They became blastocysts-the ball of cells that implants in the uterus and develops into the placenta and fetus, As far as the researchers can tell, the blastocysts are normal. Each developed at roughly the speed typical of its nuclear 11 parent". And they all produce the protein c-kit-which is made by normal embryonic cells but not by the adult cells from which their nuclei were derived. However, it is still possible that species differences between the cytoplasm and the nucleus will prevent the embryos developing further if implanted. "The results look encouraging," says Dominko. "But at this point we have many more questions than we have answers." Philip Cohen

Xenotransplant reconsideration

LEADING American researchers in the field of cross-species organ transplantation are calling for a moratorium on human trials. This week, a US Public Health Service meeting held near Washington DC will debate government policy on xenotransplantation. But Fritz Bach of Harvard Medical School and seven other specialists in xenotransplantation and related ethical issues want federal officials to defer any decisions and halt ongoing trials until there has been a full public discussion of the risks involved. "Despite the fact that lives of patients needing transplantation may be lost with delay, we believe that the risks are sufficient to warrant refraining from human xenotransplantation until public deliberations on the ethical issues have occurred," they write in an opinion piece to appear in next month's Nature Medicine. The researchers are concerned that public health could be threatened by diseases that might cross over into people from donor animals such as pigs. Although such infections haven't been seen in people who received heart, liver or brain cell implants from animals, pig retroviruses have been shown to infect human cells in the test tube (This Week, 18 October 1997, p 4). Xenotransplantation is currently allowed in the US, and is regulated only by non-binding guidelines. Kurt Kleiner, Washington DC

Gene crop axed

COTTON farmers in the US must stop spraying with the herbicide bromoxynil, the Environmental Protection Agency (EPA) has ruled. If the ban is upheld, it will sound the death knell for a variety of cotton engineered to resist the herbicide-the first time such a transgenic plant has been pulled from the market. Last year, farmers planted 170 000 hectares of bromoxynii-tolerant cotton, which is marketed by Stoneville Pedigreed Seed of Memphis. They had planned to expand this in 1998 to more than 500 000 hectares, or about 10 per cent of the cotton crop in the US. The EPA!s pesticide rules state that human exposure must be 100 times less than the lowest concentration shown to cause birth defects and cancer in laboratory mice. Residues of bromoxynil on cotton fields passed this test. But EPA officials have now invoked a further 10-fold safety factor that can be applied if pregnant women or infants are deemed to be at extra risk. Bromoxynil residues exceed this lower threshold. The herbicide's manufacturer, Rh6nePoulenc Ag Company of Research Triangle Park, North Carolina, argues that there are no new data to justify the ban. Company officials hope that the ruling will be overturned by the EPXs science advisory committee in March. But environmental activists are pressing for the engineered cotton to be kept off the market. "it specifically promotes the use of a harmful pesticide," says Rebecca Goldburg of the Environmental Defense Fund in New York. Bob Holmes, Santa Cruz

Modified Potato is Taken off the Menu NS 17 Oct 98 13

DOUBTS over the effects of genetically modified crops on health and the environment are threatening to undermine attempts by biotech companies to sell them in the European Union. For the first time, the European Commission's scientific advisers have recommended that a genetically modified plant should be withheld from the market because they cannot guarantee its safety. And Britain's environment minister, Michael Meacher, is considering imposing a three-year moratorium on transgenic crops grown for commercial use. The Dutch company Avebe this year applied to the Commission for permission to sell a potato that has been modified to produce extra starch. The potato also contains a marker gene which confers resistance to amikacin, an important antibiotic. The Commission's Scientific Com- mittee on Plants, a group of 15 independent scientists, last week said the crop, should not be licensed for sale in the EU because lt was unable to assess the risk of the gene spreading. Last month, France withdrew its consent for a Bt maize marketed by Novartis, pending a review of the risks of antibiotic resistance (This Week, 3 October, p 5). Meanwhile, British government officials were last week discussing a three-year moratorium on the marketing of transgenic crops with environmentalists and the Supply Chain Initiative on Modified Agricultural Crops (SCIMAC)-a lobbying group representing the National Farmers' Union and seed and agrochemical companies. Debora MacKenzie

The New Healers, William Clark ISBN 0195117301

AS attention shifts towards the role of genes in disease, we stand on the brink of a medical revolution. In the industrial world, the threat from infection has receded, exposing our vulnerability to the 4000 or more single-gene disorders such as cystic fibrosis and sickle-cell anaemia. Increasingly, too, we are aware of the genetic influence on heartheart disease, cancer and infection. Genebased medicine-therapy in particular-may offer as much to humanity in the 21 st century as antibiotics did in 20th. In The New Healers, William Clark takes on gene therapy with the same verve and clarity which made his previous books on the immune system and the biology of the cell such a pleasure. The main message is that gene therapy works. The first trials were on children suffering a rare immune disorder called adenosine deaminase (ADA) deficiency. Blood tests show that the healthy ADA gene transferred to their cells functions normally, restoring the immune system to full capacity But gene therapy can do more than supply a healthy gene to repair a single-gene defect. More than half the trials under way are to treat cancer or AIDS, and several novel strategies are being developed. For instance, so-called adaptive immunotherapy involves stimulating the body's natural defences against cancer by delivering genes for immune-system molecules to tumour cells. Besides gene therapy, we may soon have DNA vaccines, delivered into the body by a miniature "gene gun". These new vaccines stimulate a more effective immune response, and are being developed against hepatitis, TB and even cancer. The human genome project is likely to provide researchers with even more ideas for improving our health. But Clark sounds a warning note: we must ensure that genetic information is used wisely by inforniing ourselves about the ethical issues C, involved. Otherwise we could see a backlash that might deny us the far-reaching benefits of gene-based medicine. Susan Aldridge