Published in: America, Oct 22, 1994

When individuality begins

Modern science has seemingly brought new challenges to our philosophical and theological understanding of where a human being begins and ends. In the debate on fetal status several arguments have centered on the requirement of individuality for human status to be recognized. As is commonly known from the phenomenon of twinning, a single fertilized egg can in some cases give rise to two or more human beings. This happens when the fertilized egg or the early embryo divides into two or more genetically identical entities, which thereafter progress through the normal developmental stages of any individual fetus. Twinning does not occur after formation of an embryonic structure called the primitive streak, and the point of time where emergence of more than one individual can no longer occur is around day fourteen after fertilization of the human egg.

Roman Catholic position

Despite this, several Roman Catholics, including the pope, contend that a complete human being arises at the time of fertilization. Since this is a departure from the conviction previously held by the Church for centuries, the basis for this position is important. Previously the Church believed that some period of time was required for ensoulment to take place (40 days for male and 80 days for female fetuses), but today prominent officials of the Church put the crucial point of time at the moment of fertilization. Strange as it may sound, this new position is backed by reference to recent scientific discoveries. It is thus argued that the complete genetic code for a new individual is present from the very moment of fertilization, and that this genome is what constitutes a human individual not only in abstract philosophical terms, but also in the sense of being a program controlling the entirety of that person's identity. Thus the pope is quoted as having stated (Angelus 19/12 1993) that the program present from the first moment of existence determines not only that this is a human being but also the special characteristics of this particular human being.

Genome does not determine individuality

While there may be various other arguments that support the "human at fertilization" theory, this genetic argument is not really one of them. The genome of an individual may be shared by other individual humans as with twins, and while genetically identical, no one will dispute the unique and different individuality of any twin. Further, it is a fairly common misconception that the genes decide everything and this often, wrongly, results in a sort of deterministic view of the development of an individual human being. No doubt this stems from a popular simplification of the complex and still not entirely understood process of fetal development at the molecular level. What is clear, however, is that the genome is neither the "prime mover" of cellular differentiation and development nor does it determine those personal aspects of a human being, which makes her uniquely human. It would be futile to look for the gene controlling our taste in music or political orientation.

Role of genome in early development

From a scientific perspective, the genome is more like a constructor's manual, and like a manual it cannot build an organism or even a single cell. From the first moment of the fertilized egg, biological life and development depend on a molecular machinery to provide energy, dispose of waste and read instructions in the genetic code for new components. Which genes will be read is to some extent dependent on whether the particular gene derives from one or the other parent ("genetic imprinting"), and thus the activity of many genes is influenced by a sort of biological memory stretching back in time to previous ancestors. The particular environment in which the fertilized egg lives has also from the very first moment an impact on the function and development of the fertilized egg and the fetus. This role of the environment in shaping the biological features of an emerging human being is not only limited to the fertilized egg. The egg and the sperm is also living organisms and their previous interaction with the environment will also influence their joint product, the fertilized egg. Apart from DNA, the gametes from both parents also contribute the initial machinery of cellular material constituting the fertilized egg, and the DNA is just one component of this machinery. Through this transfer of biologically necessary material every human is directly linked in an unbroken physical chain with previous humans. The new genome resulting from fertilization is neither sufficient to construct a particular human being, nor has it a dominating role. The DNA is one integrated part of a biological organism whose uniqueness is constituted by its totality of components rather than any single molecule like DNA. It therefore seems that fertilization is just one single step in the process of creating a human individual. Several steps occur before and several steps occur after. Looking purely on the biology of a human fetus where the best description is an evolvement of features, it seems counterintuitive that its spiritual features should not also evolve in concert with its biological development.

Roots of the genome

Contemplating the nature and importance of the human genome, one realizes that this genetic code has evolved over a very long time. Most of the human DNA does not seem to be active at our present stage of evolution, and many genes and gene fragments are clearly a result of previous evolutionary steps in mammalian or even pre-mammalian history. One therefore gets the same impression of evolvement on the species-level as one gets on the individual level although the mechanics are different. Similar in both situations, however, is the complex interaction between environment and biology. In this interaction the genetic code primarily serves as a sort of memory bank, where experience on a species-level can be stored and used when it fits the environmental situation.

Human participation in natural evolution

There is no reason to think that evolution has stopped now, indeed the evolution of biological organisms may actually be speeding up. Human consciousness is now part of the environment that shapes evolution. In a direct sense we have in the last centuries modified the environment including livestock and other naturally occurring organisms. Indirectly, our mere presence and our designed modification and utilization of natural resources have also had a part in shaping evolution. The record of these modifications is held in DNA and thus preserved for future generations. In the last decennium the tools of molecular biology and genetic engineering have become much more sophisticated and powerful. This allows a much greater control over our environment and gives us the potential to handle the increasingly difficult task of making sufficient resources available for all humans in a rapidly expanding population.

Dangers in selection

The environment that we modify also modifies us. Evolution has not stopped for other biological organisms, and neither has it stopped for the human species. On a long-term perspective, the human species should also evolve new characteristics as the environment has changed. However, modern scientific tools allow us to curtail this process and suppress the natural biological diversity which is a prerequisite for evolution. Thus, genetic screening and negative selection, e.g. through abortion of fetuses or sterilisation of adults, can be a dangerous procedure from an evolutionary point of view except perhaps in limited cases of very severe abnormalities. One should at least refrain from negative selection based on features with a complex genetic and environmental causation such as behaviour.

Gene therapy of disease

Since human consciousness already in an indirect and uncontrolled way intervenes in the evolutionary process, it may be time to consider a more rational and designed intervention in the evolution of man. At the moment, therapeutic transfer of synthetic genes to humans only takes place in a fashion that does not allow preservation of such modification across generations. Gene therapy of various inborn or aquired diseases is now emerging as a powerful technique to treat some previously intractable diseases like cystic fibrosis, inborn immune deficiency, AIDS etc. For the time being this kind of therapy usually does not cure the individual patient and treatment must be repeated intermittently. For families that harbor a genetic defect, all individuals have to get the gene treatment repeatedly and also in future generations. In some cases with such an inherited genetic defect, a permanent cure in the form of genetic replacement of a defective or missing gene at the gamete or embryonic level is a realistic possibility. This would in effect eliminate the disease permanently in that particular family. Although it may still require more knowledge about the human genome, this kind of genetic engineering will almost certainly be a reality in the near future.

Enhancement through gene manipulation

While genetic repairs that are directed against specific diseases may not seem to pose a moral challenge, genetic enhancement of humans does. It is not certain when addition of new genetic information will be feasible in humans, although it has been done in animals for some time. Waiting just below the horizon, however, is the possibility of adding new capabilities to humans either as transient or as permanent, inheritable traits. Such enhancement through genetic optimization could include features like resistance to environmental carcinogens, immunological resistance to certain microbes or better metabolic utilization of food. Common for these examples is that they should be controlled by just one or perhaps a few genes, since the task would otherwise be too complicated technically. For the near future this precludes modification of traits that are controlled by multiple genes such as intelligence or psychic disposition. There is, however, no reason to exclude categorically that it may be technically possible to modify such traits in the future. This will in large part be determined by what direction we wish the research to take.

Ethical responsibility of scientists

In the wealthy Jewish-Christian societies, which at present hold the defining edge of science, direct optimization of man is a prospect which imparts a sense of uncertainty and unknown philosophical ramifications. It will thus take some time and debate before permanent optimization of man will take place in these societies. Since the technical part of molecular biology and genetic engineering is fairly simple, there is of course always the risk that societies with different cultural inhibitions could go ahead with such projects. However, so long as it is the Jewish-Christian societies which define the front of technology and science, time should allow for a thorough discussion without suddenly being faced with a technological fait accompli. Among many questions the primary one may be what is the goal of evolution and what blueprint of man serves this purpose best. If we reach a situation where we actually alter the design of man and construct an improved version, this would also be expected to have profound implications for our perception of creation. It may be that even the possibility of our participation in the design and construction of an enhanced man will have such consequences. Most scientists recognize that questions of this nature lie outside their own field of expertise and therefore welcome contributions from outside the scientific community presently dealing with genetic engineering and molecular biology. Whether directly or indirectly we do influence the evolution of man. The direction this influence takes should not be left to chance or the less scrupulous among us.