Developmental Biology

What it is and why you should know about it.
DATE: April 29, 2008
TIME: 1:00 PM EST

Scientists have grown a human ear on the back of a laboratory mouse using cartilage cells from a cow. In the peritoneal cavity of a mouse, scientists have coaxed a severed human fetal limb to grow into a tiny human hand. Scientists have also confected a human jaw bone in the laboratory, elevating "plastic surgery" to new heights. Scientists can grow human neurons (brain cells) in a Petri dish and use them to test for drug toxicity. They can also grow sections of human brain within laboratory animals to study human neurogenesis. Scientists have created hybrid animals like the "geep" (through the fusion of a goat and a sheep embryo), and they are rapidly garnering the technology to grow synthetic strands of DNA, insert them into living organisms, and alter them to breed heretofore unimaginable hybrid organisms. Scientists are also acquiring the technology to coax stem cells to become sperm and egg cells so that, one day, homosexual and lesbian couples might be able to be the genetic parents of their own offspring through IVF. This all appears to be a mix of the macabre, the medically promising, the morally good and the morally perilous. Welcome to the world of developmental biology. At the risk of over simplifying, we can describe developmental biology as the study of how the organism as a whole governs and guides its self-development and self-maintenance as a living being. Now, this marks a relatively recent development in biology. In previous decades, biology was characterized by what we might call a "parts-to-whole" approach as the field was characterized by its reduction of process to biochemical underlay, and endeavored to unlock the secrets of these fundamental biological dynamics, culminating in the monumental sequencing of the human genome. With the advent of developmental biology, the field assumes a "whole-to-part" approach as it now endeavors to study and harness the laws which govern the genesis of whole organisms. Of paramount interest here is to discover how human embryos "do it," how a one celled human zygote brings about the development of an entire human organism. Perspectives on the future possibilities of this science hold out the prospect of medical breakthroughs that were unimaginable only years ago: the elimination of certain birth defects, the generation of human organs in the laboratory, recovery of motility after spinal cord trauma, a cure for Parkinson's disease, and so on. The scientific acquisition of such knowledge is now the true holy grail of the science of developmental biology. But again, of paramount importance toward the acquisition of such knowledge is the conducting of research directly on human embryos. This is why efforts to defend embryonic human life will only be realistic and effective if they take into account the full reality of this rapidly emerging field. Undoubtedly, we must acknowledge the legitimate aspirations of this field: to further human knowledge by acquiring an understanding of the dynamics of organismic development, and to put that knowledge at the service of humanity. As opponents of embryo destructive research, we must also understand that there is no such thing as turning this field back or of saying, "stop Brave New Word, I want to get off!" Nor, in principle, is there reason to desire this. Notwithstanding the more harrowing scenarios I described above, and the way Hollywood plays on our deep-seated suspicions of such science [think of The Island, or more recently I am Legend], I would actually suggest, however, that we have nothing to fear in principle from developmental biology. I say, in principle. Are there potential perils in developmental biology? Are these extraordinarily dangerous in some respects? Of course. But those dangers in themselves do not constitute reasons for foregoing the progress of human knowledge in this particular field. Human knowledge is a fundamental human good; but from the garden of Eden onward, history has witnessed that it is the free use of knowledge--not the knowledge itself--which can lead to evil outcomes. We are, nonetheless, at a genuine turning point in human history. As Stanford's Dr. William Hurlbut, member of the President's Council on Bioethics, has affirmed, In reflecting on these dilemmas, it was immediately clear that we are at a defining moment in the progress of science. The choices our society makes now regarding embryonic stem cells (and other ethically controversial uses of biomedical technology) will put into place both the conceptual principles and practical foundations for future techniques of research and patterns of clinical practice. Once established, these moral precedents and scientific techniques will serve as the platform on which further practice will be built layer upon layer; like the foundations of a building, these will be difficult to retract or revise.[1] So, outside of setting up a commune somewhere north of Saskatoon, I would suggest that our only way forward--in order to preserve the integrity of human dignity at all stages of life in the age of developmental biology--is to work toward an adequate delineation of what many have called the "boundaries of humanity." This means working to discover solutions that will allow the science of developmental biology to go forward, while at the same time precluding the direct use of human embryos or at least substantially minimizing that use by offering ethically and scientifically acceptable alternatives. The Westchester Institute has been dedicated in full to just such a project for the past three years, and we will continue. Our efforts have been in the direction of sustained and painstaking moral and scientific consideration of what distinguishes a human organism from non-human, non-organismic biological artifacts. It can be morally licit to create the latter in the laboratory under certain conditions. But such discernment is presenting itself to be very difficult. It requires a delineation of the biologically and metaphysically minimum requirements for organismic existence. It requires us to attempt to define the set of primary, necessary and sufficient indicators of what constitutes a living human organism. Such efforts hold out the hope that such demarcation will one day offer us sound scientific and philosophical insights on which to arrive at moral judgments regarding the creation, use, and moral status of an array of biologically confected entities of genetically human origin. Again, our efforts here are motivated by the concern that many of developmental biology's pet projects would become so much easier if scientists could just work directly on human embryos to harness the laws that govern the genesis of entire organisms, organismic systems and parts. If-if a majority of Americans didn't consider it morally repugnant to manufacture human embryos solely for research purposes. How long before they are finally disabused of such an antiquated "moral taboo?" Perhaps as soon as January 20, 2009. Rev. Thomas V. Berg, L.C. is Executive Director of the Westchester Institute for Ethics and the Human Person. [1] William D. Hurlbut, "Framing the Future: Embryonic Stem Cells, Ethics and the Emerging Era of Developmental Biology," Pediatric Research, 59, 4 (2006) 6R. Dr. Hurlbut is Consulting Professor of Neurology and Neurological Sciences, StanfordMedicalCenter, Stanford University.

Copyright 2008 The Westchester Institute for Ethics and the Human Person.