As recently as the late1960's developmental biology was an unfashionable field, made up of people interested in why, if you cut up frog embryos in one direction they would still turn into frogs, but if you cut them up in a different direction they wouldn't. It was mainly concerned with sea urchins, and other obscure, useless organisms and there were not that many people in the field. Then, in the 1970's there was a technical revolution in the ability to manipulate, sequence and transfer genes between organisms. If you made changes in the genes you'd often make changes in the organism as well. This attracted more people to the field. It also reinforced the oversimplified notion of genetic determinism, where everything about an organism was held to be summed up in its genes.

Now, thirty years on, we still don't know how development really operates. Despite the fact that we can pinpoint every gene in the sea urchin, human or mouse, no genetic blueprint or program has emerged, because none exists.

There was, though, a lot of scientific activity, and some related safety and social concerns. If you could transfer genes between humans and microbes, wouldn't that be dangerous? Couldn't you cause new diseases? That led to the famous 1974 meeting at Asilomar, California, where proposals for restrictions and reforms were debated. Scientists tried to speculate on what could go wrong. They agreed on a short-term moratorium.

Then, in 1980, the Bayh-Dole Act was passed by Congress. The motivation was that because the government was spending a lot on research, but that it was difficult to turn such research into money-making businesses, allowing universities to patent the results of research funded by taxpayers would grease the wheels of commerce. And the scientists involved would get a share of this, too.

Also in 1980, the Chakrabarty decision was handed down by the U.S. Supreme Court. The General Electric Corp, known for its consumer appliance business, was also in the business of creating oil spills, like the PCB dump in the Hudson River. They wanted to create genetically engineered bacteria that could eat up the oil. And they wanted a patent on it. The U.S. Patent Office rejected the patent, holding that living organisms were not patentable. The courts agreed with General Electric, holding in one decision that bacteria were closer to chemical substances than living things. When the Patent Office appealed to the Supreme Court, the Court found in GE's favor, approving the patent in a 5-4 decision.

This opened up the prospect of intellectual property in anything genetically modified. Not long after, biotech companies started taking out patents on mice with human genes, human cells, etc. And they realized: you could make lots of money with this.

1980 also saw the election of Ronald Reagan. Up until then, geneticists and embryologists would justify their work on disease-related genes in their grant applications by the potential for prenatal or preimplantation diagnosis. Of course this implied the option for elective termination of pregnancy and other techniques that involved the destruction of human embryos. Under Reagan such possibilities were no longer entertained by NIH policy makers. It became more fashionable and politically prudential for scientists to say maybe we can some day correct these genes right at the beginning, through genetic manipulation, rather than destroying embryos. This represented a tacit shift in the justification of biological research. Not screening, but prospective genetic engineering. Abortion politics made it more respectable to justify research in developmental biology by the prospect of genetic engineering.

The new embryo manipulation technologies spawned by developmental biology made some people's imaginations run wild. In 1988, Joseph Fletcher, a University of Virginia philosophy professor and Protestant minister sometimes called the "father of bioethics," suggested using embryo manipulation to create "parahumans" -chimeric mixtures of human and nonhuman organisms to do dangerous and demeaning jobs.

This past year, a columnist in Florida, proposed that rather than employing U.S. soldiers to clean up the uranium wastes left over from the first Gulf War, (which have proven an obstacle to the pursuit of the current Iraq war), human-ape chimeras be engineered to perform this hazardous task.

But scientists and medical researchers also started holding out new and bizarre possibilities. As the technology progressed taboos rapidly fell by the wayside. Through the 1980s and 90s, there was general acceptance among scientists of using human embryos left over from IVF procedures for research, but a reluctance to produce new embryos solely for experimental purposes. Then, in 1997, Dolly the sheep was cloned and in 1998 the production of human embryonic stem cells was announced. Using the cloning techniques, which involve putting the nucleus of a body cell into a female egg cell from which the nucleus has been removed, it is possible to make an embryo that is a genetic replica of an existing person. Such clonal embryos have potential research and medical uses. They could be used, for example, to trace the embryonic origins of a disease, or to construct tissue transplants that the body's immune system won't reject. But of course these procedures would involve creating new human embryos for experimental purposes.

So how has this conflict been dealt with? Some scientists are now arguing that these clonal embryos are not "real" human embryos, because they will almost inevitably develop, if implanted into a woman, into "abnormal" fetuses or newborns, and can therefore can justifiably be used for experiments. One philosopher has proposed naming such embryos (from the Greek), "epidosembryos," i.e., embryos made for the common good. Few secular scientists now oppose producing human embryos for scientific research.

But this fairly sudden change in what is considered acceptable should give us pause. Following this logic could really bring us to the "Brave New World" envisioned by Aldous Huxley in his 1932 novel. It is important to recognize, however, that the supposed "right" to manipulate and find uses for human embryos is entirely distinct from reproductive autonomy-the right of someone to become a parent or not, as she chooses. One can fully support the second, and indeed consider it an inalienable human right, while having grave concerns about the implications of the first for our increasingly commercialized and commodified culture.

The next taboo that fell by the wayside is that of not making a full term human clone. People have advocated using cloned embryos to make human stem cells, even though the efficacy of embryonic stem cell therapies has not been demonstrated. (Despite years of attempts, no mice have been cured of any health-impairing condition through the use of mouse embryonic stem cells. Adult stem cells may be better; they've been used successfully in clinical trials and elsewhere.) In any case, the pressure for making a full term human clone is growing. Indeed, if stem cells from an embryonic clone of the patient are (as it is claimed) better than those from "off-the shelf" embryos, why not bring the clone to full term so that a fully-developed kidney, or definitive bone marrow can be harvested for the patient's use.

The resulting full-term clones, assuming it is intended to make them part of human society, rather than (as some have suggested) causing them to develop without brains so that they can be used only for spare parts, will be experimental products. Even if cloning can be made reliable in animals, transferring experimental technology from one species to another always leads to unexpected results. So any proposals to do full term cloning in humans, or germline engineering, which is modification of human embryos to pass on traits to a next generation, will violate the Nuremberg Conventions established in the aftermath of World War II. The conventions say that you can't do experiments without voluntary consent, or with informed consent by parents or custodial relatives. In cases where the individual is being brought to term using experimental methods to primarily serve the health needs of a genetic prototype, there is clearly a deep conflict of interest and no real possibility of informed consent.