Coming to Life

Director of the Max Planck Institute for Developmental Biology in Tübingen, Germany, and Nobel laureate for Physiology in 1995, Christiane Nüsslein-Volhard is one of the founders of modern complex genetics and an active member of the National Ethics Council of Germany. This makes her one of the most qualified people in the world to outline the terms and boundaries of the current debate about human embryo research. To what extent should embryos be manipulated or protected? Is a human embryo a human being? Is the blastocyst already to be considered a live human being, or if not, when do the legal and moral definitions begin to apply: shortly before implantation or just after fertilisation? "The debate will continue until a general consensus is found" commented Dr. Nüsslein-Volhard. But if we look at national legislation, from Germany's embryo-protection law to the less rigorous British one, this consensus still seems far away. Regulations vary widely across the world and Dr. Nösslein-Volhard expressed her concern that in many cases policy makers are overly-influenced by potential developments, which are currently only speculative scenarios, rather than actual scientific possibilities.

These hot political topics of cloning, gene therapy, designer babies and stem cell research were addressed from the perspective of someone who has spent one's life in research. Dr. Nüsslein-Volhard set out her vision of what is real, what is plausible and what is utopian according to the current status of scientific knowledge.

"The idea of designer babies and the possibility of improving human beings by selecting embryos with a specific combination of genetic traits as opposed to others, belongs truly to the realm of science fiction," in Dr. Nüsslein-Volhard's view. Therefore, insisting on regulations based on the potential of these techniques is a waste of time. Morally questionable practices, such as the reproductive cloning of humans, have been almost universally rejected by individual scientists as well as governments, which suggests that overly restrictive laws designed to restrain unethical scientific enquiry are totally unnecessary.

Dr. Nüsslein-Volhard continued her presentation by questioning the moral status of the early human embryo: "At what point does a human embryo need to be protected by law from destruction?" Assuming that the crucial parameters are the inviolability of human dignity and the fundamental significance of the protection of life, the speaker highlighted that the arguments used by philosophers and politicians are often based on faulty scientific assumptions. In particular, it is often stated that human development is a gradual process with no discernible milestones and that a zygote has the complete potential to develop into a human. She conceded that this last statement is true for chickens, frogs and flies, for example, but in mammals implantation into the mucous membrane of the uterus (nidation) is a crucial step to allow development to continue after the blastocyst stage. Mammalian embryonic development, therefore, can be defined as a discontinuous process. In the laws of the United Kingdom, a pre-implantation embryo is legally different to a human, but in Germany an embryo is classified as human immediately after the conjunction of the two nuclei from sperm and egg. In other countries the regulations are different and often complicated. Societies always stand behind rules and share with the scientific community the responsibility for finding a compromise.

The speaker ended by calling for a set of international commitments designed to regulate the use of human embryos in medical research. This would, she argued, prevent the current anomalous position in which some countries benefit from treatments developed as a result of research using human embryos which would not be allowed within their borders. (In Germany, for instance, the law forbids the production of human embryonic stem cells, but there are no legal provisions governing their importation.) Although Dr. Nüsslein-Volhard said that there is "no single right solution", she feels that human-animal chimeras should not be allowed and achieving a high success rate in humans should be a criterion that can be satisfied before any experimental treatments on them could take place. She concluded that medical research should not be prohibited for fear of misuse and that the only limitations on the freedom of science and research are those inherent in basic rights. The search for potential new therapies and improving the prospects of curing disease must not be abandoned.