The Dignity of the Human Embryo

Por Angelo Serra – Publicado en The Human Life International – Medicina e morale    ISSN  0025-7834 2002, vol. 52, no1, pp. 63-80 

In 1986, a false supposition or pretext of irresponsible science deprived the “recently conceived” human being of its title and value of “son.” The new, “recently conceived” life arising from the fusion of the maternal and paternal gametes is just beginning a marvelous dialogue with his or her parents–above all the mother–but is seen on a biological, psychological, mental and spiritual level as not having the name “son” or “daughter” until the fourteenth day after conception. 

Before that day one “should” consider him or her as “bunch of cells”, and not as a “human being,” the gift and living expression of the love of a father and mother. The law also followed this supposition and pretext: before that fourteenth day, the law negates the “right” to be a son, reducing him to a mere “disposable object,” to the point of conceding his ownership–something which we never before could have imagined!
 
In his encyclical Evangelium vitae, Pope John Paul II condemned this inhuman situation: “Some people try to justify abortion by claiming that the result of conception, at least up to a certain number of days, cannot yet be considered a personal human life” (n. 60). But he firmly continues “But in fact, ‘from the time that the ovum is fertilized, a life is begun which is neither that of the father nor of the mother; it is rather the life of a new human being with its own growth. It would never be made human if it were not human already’” (n. 60). And he insists “This has always been clear, and …modern genetic science offers clear confirmation.” (n. 60 quoting the Congregation for the Doctrine of the Faith’s, Donum vitae, 22 Feb. 1987, I, No. 1: AAS 80 (1988), 78-79)
 
In the small space available to us, let us try to formulate in a very schematic way the last affirmation that we have just cited from Evangelium vitae. In fact, a rigorous scientific analysis of the first stage of development following conception and lasting about fourteen days leads to one unique conclusion, i.e., that after the fusion of the maternal and paternal gametes begins the vital cycle of a “new human subject” to whom rightly belongs the sweet name of “son,” in whom there is a dignity equal to that of the father and mother. We will now insist on the four essential points of this analysis.
 
1) The first point is related to the zygote. When the process of fertilization is concluded, a few seconds after the fusion of a sperm and an egg, one can observe how a wave called “calcium wave,” provoked by a passing rise in the intracellular concentration of calcium ions and by the action of PCL-zeta, a recently discovered paternal protein, rapidly extends across the fertilized egg. It is the signal for the activation or beginning of embryonic development.

This new cell is the zygote, the one-cell embryo; a new cell that begins working as a new system, i.e., as a unity, an ontologically one living being, like any other cell in a mitotic phase, but with some particular properties. Among the many activities coordinated by this new cell over a period of 20 to 25 hours, the most important are: 1) the organization of a new genome, which is a kind of main information center coordinating the development of the new human being and all its subsequent activities; 2) the initiation of the first mitotic process, which induces the embryo to divide itself into two cells. 

Concerning this new cell, one must underline two principal aspects: first, the zygote has its own precise and proper identity; that is, it is not an anonymous being; secondly, it is intrinsically oriented towards a well defined development, i.e., to form a human subject with a precise bodily form; both aspects, identity and orientation, are essentially dependant on the genome, in which is inscribed the genetic information in very determinate molecular sequences. This substantially unvaried information establishes your belonging to the human species, defines your individual biological identity and carries a codified program endowing it with enormous morphogenetic potentialities, i.e., intrinsic capacities which are realized in a gradual and autonomous way throughout the whole rigorously oriented epigenetic process. A quick glance at the successive stages of development will enable us to establish definitively that the zygote is the exact point in space and time in which the human individual initiates his or her own proper living cycle.
 
2) The second essential point in our analysis grows out of the first stage, which goes from the zygote to the blastocyst. During a period of about five days, a rapid cellular multiplication occurs under the control of a great number of genes implicated in the many events of the mitotic cycle and in the production of the proteins necessary for the structure and functioning of the growing number of cells. One observation merits special attention. Today we know for certain that the new genome constituted in the zygote assumes control of the entire epigenetic process from the very first stages of development. All this has also been demonstrated in human embryogenesis. Through the studies of P. Braude, V. Bolton and S. Moore, who collectively proved that, at least in the passage from 4 to 8 cells, the new genome shows itself to be active in controlling the production of new proteins. It has been demonstrated recently that other genes – at least one hundred until now – are active from the zygotic stage to the implantation.
 
These facts, whose number is continually rising thanks to progress in technologies and analysis of the genome, give us a totally convincing demonstration that the new genome formed in the moment of fertilization is the foundation constantly sustaining the structural and functional unity of the embryo, which develops along a trajectory having a constant direction. The well-known embryologist L. Wolpert has rightly stated that “the true key for understanding this development lies in cellular biology, in the process of transduction of signals and in the control of the expression of the genes that carry into effect the modifications of state, movement and growth of the cell.
 
All this is exactly what occurs from the zygote to the blastocyst stages. In fact, from the stage of 2 to 8 cells, these remain united to each other by means of microvilli and intercellular citoplasmatic bridges that permit the transmission of signals between cells, something supremely important for ordered development. This contact is highly evident in the morula 8-32 cell stage, when these adhere to each other more tightly, maximizing their areas of contact and forming particularly complex bonds that facilitate the rapid intercellular passage of ions and molecules. This signal favors the process of normal development which, on the other hand, can see itself changed by the absence of only one of the uniting or connecting family of proteins. Under the action of these sign-bearing molecules that precipitate the entry into action of other genes, between the third and fourth cellular cycle, a net differentiation occurs between two types of cells which give rise, respectively, to two cellular lines, the trophoblastic and the embryoblastic. This morphological and functional heterogeneity becomes even more evident during the 6th and 7th cycle, when the blastocyst is already formed of between 64 and 128 cells. Hence one can distinguish three types of cells, histologically different, with different destinies. This gives rise, respectively, to the mural and polar trophoblast derived from the differentiation in the trophoblastic cell line, and the endoderm and primitive ectoderm derived from the differentiation of the embryoblast or internal cellular mass (ICM).
 
3) Now comes the second stage, from the blastocyst to the embryonic disc that constitutes the third essential point in our analysis. One observes the expansion of the blastocyst, which frees itself from the pellucid zone through which it had protected itself until this moment; its implantation in the uterus – still defined today as “a paradox of cellular biology” difficult to explain with current knowledge – during which mother and embryo do everything possible to establish a marvelous harmony despite a difficult situation; and the continuation in an uninterrupted way of differentiation, organization and growth. At about the 8th day from fecundation appears the amniotic cavity, which becomes the environment in which through differentiation the embryonic disk is formed, a structure with two plates or sheets derived from the differentiation of the primitive ectoderm and endoderm. Around the 10th day, the amnios is differentiated, and the polar trophoblast with the extraembrionic mesoderm give place to the corion, which converts itself into the fetal part of the placenta. Between the 11th and 13th day after fertilization, the embryonic disc arrives at a diameter of some two tenths of a millimeter, and, approximately at the 14th day, one can observe in the caudal region a densely compact group of cells called the primitive line, which indicates the formation of a third layer of cells, the mesoderm, and marks the initiation of morphogenesis.
 
4) Thus we arrive at the fourth point of our analysis. In this structural foundation marvelously organized in 15 days, all development would cease if the embryonic disc were separated from the annexed structures with which it forms a unique whole, defines the general plan of the body, produces the definition of the different organs and tissues, out of which follow organogenesis and histogenesis. At about the 5th week of gestation, when the embryo is a centimeter long, one encounters an already well formed primitive brain, heart, lungs, gastrointestinal apparatus and genitourinary part. During the 6th week the buds of the extremities are already clearly visible, and towards the end of the 7th week, the bodily form is already complete.
 
At this point, a spontaneous question arises. If the essential lines of development of the human zygote noted from the first 15 day stage to the embryonic disc stage with its 4 to 8 million cells, is an objective description of what really occurs–and nobody who is sufficiently informed can deny it–can one then honestly affirm that in each one of the stages of embryonic development from the zygote to the embryonic disc, human embryos are no more than “groups of a few cells,” or “a mass of genetically human cells,” or “ a cluster of more or less homogeneous cells,” or “a mass of pre-programmed, weakly organized cells?” Or, as has recently appeared in major newspapers, and was attributed to a Nobel prizewinner, “the embryo in this stage is nothing more than a bunch of cells?” In order to more easily understand the gravity of these affirmations, which falsify the objective reality of what a human embryo is in its first 15 days of life, let us use the following analogy: nobody could define, (except in a clearly contemptuous way) a structurally and functionally well designed brick house as a “pile of bricks.” On the other hand, “a bunch” would correctly describe the collection of bricks, piled up without order or harmony, with which the house was built. The accurate image of the embryo is obviously the first one described and not the latter one.
 
At this moment we have to return anew to the question: “When does the life cycle of a human individual begin?” When can a father and mother really call their recently conceived one a “son” or “daughter”, something that the mother already feels while he/she is taking the 5 day trip down the Fallopian Tube?  Basing ourselves on what we have said until now, the answer appears evident.  However, a new reflection leads us to the definitive answer.  That reflection is not merely descriptive, but spontaneously grows out of the logical growth in profundity of the biological process itself – defined by the great embryologist C. H. Waddington as “the continuous emerging of a form from the preceding stages” or epigenesis.  In fact, this line of growing profundity makes three characteristic properties evident.
 
The first property is coordination.  From everything that we have said, it is totally evident that embryonic development from the fusion of the gametes to the formation of the embryonic disc, about 14 days from fertilization, is a process which manifests a coordinated sequence and an interaction of molecular and cellular activities under the control of the new genome, which in turn is molded by an uninterrupted cascade of signals transmitted from one cell to another,  from the internal and external environment to each of the cells, and within these, from the citoplasm to the nucleus.  Precisely, this undeniable property, which makes itself each time into something more complex and rigid during its morphogenesis, implies, even demands the rigorous unity of being that is self-developing.  As the investigation advances, this unity is presented by the new genome in which an extremely elevated number of genes regularly assures the exact time, the precise place and the specificity of the morphogenetic events.  All this leads to the conclusion that the human embryo–like any other embryo –even in its very first stages is not “a bunch of cells” but a complete embryo in each stage, and that in its first 14 days, it is a real individual in that all the individual cells are integrated in a unique dynamic processthrough which the embryo autonomously realizes, step by step, its own genetic space, its own proper space as an organism.
 
The second property is continuity.  One cannot deny, on the basis of the facts presented, that with the fusion of the gametes a new life cycle is initiated.  The zygote is the “point of departure” of a new organism truly encountered in the beginning of its own life cycle.  If we consider the dynamic profile of this cycle in time, we can clearly see that it proceeds without any interruption.  This is something that the same Warnock Committee clearly recognized in the following terms:  “Once the process starts, no part of this process of development is more important than another; these are parts of a continuous process, and if each stage is not normally produced at its right moment and with its correct cadence, the development stops.”  In fact, following a logical induction of facts, there is no existence of a first cycle of 14 days of a genetically human but anonymous living being that terminates in the embryonic disc stage, followed by a second cycle of a real human being – which goes from the embryonic disc forward. Quite to the contrary, what exists is an uninterrupted and progressive differentiation of a determinate human individual, which begins at the zygote stage and continues in conformity with a unique and rigorously defined plan.  The property of continuity therefore implies and establishes the unity or singularity of the new human subject: from the fusion of the gametes forward, one always deals with the same and identical human individual with his proper identity in autonomous self-construction, while passing through different stages that are each time qualitatively more complex. 
 
The third and most important of the properties, although it is generally passed over, is graduality.  The final form is arrived at gradually.  This is an ontogenetic law, a constant in the process of gametic reproduction, according to which the human individual must begin its own life cycle as an individual cell.  Such a constant implies and demands a regulation which must be intrinsic to each and all of the embryos, which from the zygotic stage maintains the development permanently oriented towards the final form.  Precisely because of this intrinsic epigenetic law inscribed in the genome and which begins to act from the fusion of the gametes, every embryo–and hence also the human embryo–permanently maintains its proper identity, individuality and unity: it is permanently and uninterruptedly the same and identical individual during the entire process of development from fertilization forward despite the growing complexity of his totality. 
It is precisely these characteristics that distinguish the “individual.”  Hence logical induction from facts provided by the experimental sciences – whose number and quality continually grow, rigorously confirming the present conclusion – lead to the only possible affirmation, laying aside eventual contradictory evidence, that in the moment of the fusion of the gametes, a real human individual begins his own existence or life cycle during which, given all the necessary and sufficient conditions, all the potentialities with which he/she is intrinsically endowed will be realized.  Hence, the living embryo, which began from the fusion of the gametes, is a real human individual, not a mere “bunch of cells.”
 
From that moment, he is “son:” a barely budding flower that merits all love and attention!  He has the samedignity as those that gave him life as well as the same fundamental rights.
 
This is the “human individual,” rightly called “son,” which has the right to his life.  The concept “person”–that does not fall under the competence of science – takes nothing away from the first.  It only completes it, giving reasons for its particular dignity, which nobody can avoid recognizing after some self-reflection.
 
Obviously, this conclusion, which retains its validity and force against all objections, has its consequences at the scientific, technological, medical, social, legal and political levels. The biotechnological culture that is slowly taking over society and poisoning it will not give way to the truth:  loaded with prejudices and full of private interests, it will continue to deceive and delude.  It will not yield even to the evident truth that if what is done today with millions of human embryos had been done with the “bunches of cells” which began the lives of the scientists whom we admire today, we would have to affirm coherently that they would have had their ownhardly begun lives taken away, with perhaps non-negligible repercussions for society.
 
Unfortunately, in this culture “children” have become a “product” that must be controlled.  Pope John Paul II inEvangelium vitae has shown us our urgent task:  “What is urgently called for is a general mobilization of consciences and a united ethical effort […] All together, we must build a new culture of life” (n. 95).