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Over-simplification is the enemy of accuracy. This chapter does not tell you how genetics works, and it does not tell you that genetics does not work. It tells you far less than you need to know to perform science, but at least as much as you need to make social and political judgments about how to use the science.

The section titles, below, are followed by

There are many more resources in the Appendix.














BOX 2.1 How Many Genes Do We Have?

BOX 2.2 The Great Gene Sweepstakes

BOX 2.3 The Natural Number of Chromosomes

BOX 2.4 Three Biological Parents?

BOX 2.5 Metaphors and Personalities in the HGP

BOX 2.6 Mysterious Junk

BOX 2.7 The Monkey That Did Not Glow in the Dark

BOX 2.8 Scientific Theology, or Theological Science




If you don't know how genes work, you're in good company. No one does. Not exactly. It almost seems that the more we learn, the less we really know.

That doesn't mean we know nothing about the process, and it certainly doesn't mean we can't affect it. We can — and do — swap genes in and out of completely unrelated species. We can:

  • create bunnies that glow in the dark
  • make lab mice with specified genes turned permanently on or off
  • force salmon to give birth to trout
  • produce crops that are resistant to one particular weedkiller

There are problems with all these applications. Most are inefficient, and at least some have unexpected side-effects or ramifications. They do essentially work, at least some of the time, but there are an awful lot of surprises — most of them unpleasant — along the way.

Partly, that's just life near the cutting edge of science. Physics and cosmology have massive unanswered questions, and they don't stop us sending rockets to Mars. But when those missions fail, as they rather frequently do, the problems are usually mechanical, rather than theoretical or acutely surprising. Biology is still in the scientifically fascinating place where experimental failures point the way to greater theoretical, not just technological, understanding.

We have not been able, despite fifteen years of intensive effort, to perform "gene therapy" successfully on people (see Chapter 6), let alone "enhancement" (see Chapter 7). Not only are there ethical questions about human experiments (see also Chapter 3, on cloning), and social questions of exploitation and abuse (see Chapter 4, among others) — there also remain what may be fundamental scientific questions.

This chapter can only give the sketchiest of overviews; entire textbooks are devoted to the subjects involved. Most of the discussion in the rest of the book does not require that you master the technical details, even at the very simple level presented here. Given the general idea of, say, cloning, it's perfectly possible to discuss it sensibly without knowing much about how it is done. ...


Five Parents? Do We Hear One? Seven?

There are several ways you can have more than the usual two parents. Adoption is the easiest, but technology expands the options. This was the headline of a paper in Reproductive BioMedicine Online:

Case report: Grandma, mother and another — an intergenerational surrogacy using anonymous donated embryos

But the London Daily Mail got right to the point of the same story:

The IVF twins who have five parents

A severely infertile couple used the woman's mother as a surrogate, to bring to term two donated leftover embryos. With great care and difficulty, the couple managed to legally adopt the twins.

That's a heartwarming — true — story, but some advocates of Human GE seem to take great delight in making up similar tales. Princeton Professor Lee Silver, for example (author of Remaking Eden; see Chapter 10), concocted one about a woman who used an egg donated by her twin sister, and used it to conclude (idiotically) that:

"the children of all identical twins will be found to have two genetic mothers or two genetic fathers ..."

He was mangling the idea of genetic "fingerprinting" — it cannot distinguish twins, which certainly does not make them both the parent of a child one of them has! But what's really going on?

Consciously or unconsciously, Silver is blurring the question of parenthood, because that's what some of the technologies he describes would do. If you alter an embryo's genes, or add an artificial chromosome, the child literally won't have the same relationship to the parents as we do. Silver himself forecast descendants who are genetically so different they are another species — related to no humans at all.

At the other extreme, of course, a woman could theoretically have herself cloned, using her own egg and a piece of her own tissue. This almost certainly wouldn't work, given the failures of animal experiments (see Chapter 3), but the tabloids could say it would give new meaning to the concept of the single-parent family.

Finally, if that two-of-the-five-parents couple were later to divorce, with joint custody, and if they both remarried ... those kids would, in some sense, have seven parents!



Free Documents from the Web

Links were checked and functioning as of 5/08/05; they are supposed to open in new windows. Please report broken ones.

"Unraveling the DNA Myth: The Spurious Foundation of Genetic Engineering," by Barry Commoner, was first published in Harper's, 02/02. Updates and comments on readers' responses are available at

"Death of the Central Dogma," by Dr Mae-Wan Ho, 09/03/04, is at the Institute of Science in Society (ISIS) website, which includes many other articles; memberships and books are for sale.

The US Department of Energy, which coordinated the Human Genome Project, still maintains a large and informative website, although the project is technically over. So do the National Institutes of Health (here) and other partners such as the UK Wellcome Trust (here).

The leading scientific journals Nature and Science both keep some important content free to the wider public, though you may have to register. See in particular Nature's "Web Focuses" and Science's "Essays on Science and Society."




Ruth Hubbard and Elijah Wald, Exploding the Gene Myth, Beacon Press, 2nd ed. 1999; Professor Emerita of Biology at Harvard, Hubbard knows both science and people, while Wald makes sure the rest of us can understand.

Richard C. Lewontin, Biology As Ideology: The Doctrine of DNA, Harperperennial, 1993; "the most subversive book to be published in English in 1993," by the Alexander Agassiz Professor of Zoology and Professor of Biology at Harvard University.

Richard C. Lewontin, The Triple Helix: Gene, Organism, and Environment, Harvard University Press, 2000.

Jeffrey M. Smith, Seeds of Deception, Yes! Books, 2003; focuses on GE food, but much of the science is relevant.

James D. Watson, The Double Helix, originally published by Atheneum, 1968; Norton Critical Edition (including reviews and essays), New York, 1980.