Monday, June 29, 2009

Why pro-life? Part 2: Science and the unborn

Note: See the original post in this series.

The pro-life position is that elective abortion unjustly takes the life of an innocent human being and ought to be prohibited by law. The argument may be simply formulated as follows:

1. It is morally wrong to intentionally kill an innocent human being;
2. Elective abortion is the intentional killing of an innocent human being;
3. Therefore, elective abortion is morally wrong.

If the two premises are true, the conclusion logically follows. Premise (1) is a basic moral principle; Premise (2) is a factual, biological claim. In this post I'll defend Premise (2).

A new organism at conception

Human reproduction occurs when a male gamete (a spermatozoon or sperm) penetrates and fuses with a female gamete (an ovum or egg) to form a single cell. This union is called fertilization (because the egg is fertilized by the sperm) or conception (because a new organism is thereby conceived). The successful completion of the fertilization process results in the coming into existence of a new, one-celled human organism—the beginning of the life of a new individual. At this one-cell stage, the organism is called a zygote.

In a detailed scientific analysis of the beginning of human life, Dr. Maureen L. Condic concludes:

Based on universally accepted scientific criteria, a new cell, the human zygote, comes into existence at the moment of sperm-egg fusion, an event that occurs in less than a second. Upon formation, the zygote immediately initiates a complex sequence of events that establish the molecular conditions required for continued embryonic development. The behavior of the zygote is radically unlike that of either sperm or egg separately and is characteristic of a human organism. Thus, the scientific evidence supports the conclusion that a zygote is a human organism and that the life of a new human being commences at a scientifically well defined "moment of conception." This conclusion is objective, consistent with the factual evidence, and independent of any specific ethical, moral, political, or religious view of human life or of human embryos.
Testimony from leading scientists and embryology textbooks confirm that conception marks the beginning of a new human life.

"Human development begins at fertilization when a male gamete or sperm (spermatozoon) unites with a female gamete or oocyte (ovum) to form a singe cell—a zygote. This highly specialized, totipotent cell marked the beginning of each of us as a unique individual."
The Developing Human: Clinically Oriented Embryology (2008)

"In this text, we begin our description of the developing human with the formation and differentiation of the male and female sex cells or gametes, which will unite at fertilization to initiate the embryonic development of a new individual. ... Fertilization takes place in the oviduct … resulting in the formation of a zygote containing a single diploid nucleus. Embryonic development is considered to begin at this point …. This moment of zygote formation may be taken as the beginning or zero time point of embryonic development."
Essentials of Human Embryology (1998)

"It needs to be emphasized that life is continuous, as is also human life, so that the question 'When does (human) life begin?' is meaningless in terms of ontogeny. Although life is a continuous process, fertilization is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed."
Human Embryology & Teratology, 2nd ed. (1996)

"The development of a human begins with fertilization, a process by which the spermatozoon from the male and the oocyte from the female unite to give rise to a new organism, the zygote."
Langman’s Embryology, 5th ed. (1993)

"It is incorrect to say that biological data cannot be decisive. … It is scientifically correct to say that an individual human life begins at conception, when egg and sperm join to form the zygote, and this developing human always is a member of our species in all stages of its life."
Dr. Micheline Matthews-Roth, Harvard University Medical School

"To accept the fact that after fertilization has taken place a new human has come into being is no longer a matter of taste or opinion. The human nature of the human being from conception to old age is not a metaphysical contention; it is plain experimental evidence."
Dr. Jerome LeJeune, University of Descartes
Discoverer of the Down syndrome chromosome

"The beginning of a single human life is from a biological point of view a simple and straightforward matter—the beginning is conception. This straightforward biological fact should not be distorted to serve sociological, political, or economic goals."
Dr. Watson A. Bowes, University of Colorado Medical School

"I have learned from my earliest medical education that human life begins at the time of conception. ... I submit that human life is present throughout this entire sequence from conception to adulthood and that any interruption at any point throughout this time constitutes a termination of human life. ... I am no more prepared to say that these early stages [of development in the womb] represent an incomplete human being than I would be to say that the child prior to the dramatic effects of puberty ... is not a human being. This is human life at every stage."
Dr. Alfred M. Bongioanni, University of Pennsylvania

"I think we can now also say that the question of the beginning of life—when life begins—is no longer a question for theological or philosophical dispute. It is an established scientific fact. Theologians and philosophers may go on to debate the meaning of life or purpose of life, but it is an established fact that all life, including human life, begins at the moment of conception…. I have never ever seen in my own scientific reading, long before I became concerned with issues of life of this nature, that anyone has ever argued that life did not begin at the moment of conception and that it was a human conception if it resulted from the fertilization of the human egg by a human sperm. As far as I know, these have never been argued against."
Dr. Hymie Gordon, Mayo Clinic

In 1981 a U.S. Senate judiciary subcommittee held hearings on the question of when human life begins. World-famous medical experts, including several of those quoted above, were asked to testify. The Official Senate Report reached this conclusion:

Physicians, biologists, and other scientists agree that conception marks the beginning of the life of a human being—a being that is alive and is a member of the human species. There is overwhelming agreement on this point in countless medical, biological, and scientific writings.
The subcommittee also noted that "no witness [who testified before the subcommittee] raised any evidence to refute the biological fact that from the moment of conception there exists a distinct individual being who is alive and is of the human species. No witness challenged the scientific consensus that unborn children are 'human beings,' insofar as the term is used to mean living beings of the human species."

Four features of the unborn

Four biological features of the unborn human (from conception onward) are important to his or her status as a full-fledged human being. First, the unborn is a genetically and functionally distinct entity, separate from (though dependent on and resting inside of) the mother. Her growth and maturation is internally directed, and she has her own unique genetic fingerprint (a genomic sequence of 46 chromosomes, 23 inherited from each parent) that is different from any other cell in the mother's body. The unborn develops her own brain and central nervous system, and she may have a different blood type and sex than the mother.

Second, the unborn is living. She meets all the biological criteria for life: metabolism, cellular reproduction and reaction to stimuli. In addition, she is visibly growing at a remarkably fast rate.

Third, the unborn is human, a member of the species Homo sapiens. Each being reproduces after its own kind, so the offspring of human parents can only be human. Moreover, the unborn carries DNA with a recognizably human genetic signature. She may not seem to "look" human (at least in her earlier stages), but in fact she looks exactly like a human at that level of human development. Notes Gregory P. Koukl, "Living things do not become entirely different creatures in the process of changing their form. Rather, they develop according to a certain physical pattern precisely because of the kind of being they already are."

Fourth, the unborn is a whole organism, not part of another living thing. Her complete genetic makeup is established at conception, determining to a large extent her physical characteristics (sex, eye color, skin color, bone structure, etc.). Explains Francis J. Beckwith, "At conception, the 'genotype'—the inherited characteristics of an individual human being—is in place and it plays the same role in the human organism as it does in all living organisms: it is highly complex information that instructs the unfolding of the organism's intrinsic potential. The conceptus, from the very beginning, is a whole organism, with certain capacities, powers, and properties, whose parts work in concert to bring the whole to maturity." The unborn is a unitary, self-integrating entity, needing only the proper care and nutrients to proceed through the various stages of human development.

After conception, the growth of the unborn human being is rapid. By 24 days, the heart is beating regularly; at 43 days, electrical brain waves can be recorded; at seven weeks, the unborn human has the appearance of a small infant, with complete fingers, toes and ears. In the ninth and tenth weeks, the unborn child squints, swallows and retracts his or her tongue. At four months, the baby is swimming, kicking and turning somersaults.

Common confusions

Three clarifying points should be made. First, it is important to note that sometimes the term "human being" or "human" is used in a different sense than in which I use it here. Often it is used in a social, cultural or moral sense, rather than a scientific, biological one. For the sake of clarity in this discussion, I will use the term "human being" to mean an individual, living member of the species Homo sapiens. That's what the unborn (and you and I) is biologically. The question then becomes the moral status of that young human being -- whether he or she counts as a "person" and should be included in the moral community. (That's the subject of Premise (1), and my next post in this series.)

Second, pro-choice advocates often say that "no one knows when life begins." But as has already been made clear, this is plainly false. There is a dispute as to when, precisely, in the fertilization process the new organism has come into existence, but there is no doubt that upon completion of fertilization a new human organism exists—and it is this organism, at a later stage of prenatal development, that is killed by abortion.

The real debate isn't about when life begins, but about the value of life at its different stages.

Moreover, ignorance about when life begins is actually a good reason against abortion. Consider an example used by Scott Klusendorf. "What would we think of a structural engineer who blew up an old building without first making sure no one was inside?" he asks. "Yet that is exactly what some suggest we do. They say, 'We don’t know if the unborn are human, but we are going to kill them anyway.'"

Third, there is frequently confusion about the status of the unborn as a whole organism. Some liken the unborn to the sperm or egg, or to a patch of skin cells or a strand of hair—living human tissue, perhaps, but certainly not a human being. But as I mentioned in more detail earlier (and Dr. Condic clearly explained), the unborn is a whole organism, not part of another living thing. Sperm, eggs and skin cells are mere parts of a larger organism -- they themselves are not self-integrating entities whose parts work together to bring the whole to maturity, as is the unborn human from the zygotic stage onward.

Bottom line

It is clear that Premise (2) is correct. Abortion, by definition, is the intentional killing of the unborn entity, a full-fledged member of the species Homo sapiens.