When Does Human Life Begin? The Final Answer
A human embryologist speaks out about socio-legal issues involving the human embryo.

C. Ward Kischer
Reproduced with Permission

Since 1973, when Roe v. Wade was adjudicated, there have been many socio-legal issues involving the human embryo. Abortion, partial-birth abortion, in-vitro fertilization, fetal tissue research, human embryo research, stem cell research, cloning and genetic engineering are core issues of Human Embryology. Every one of these issues has been reduced to a question of when human life begins. And, that question is as prominent in the public media today as it was first posed in 1973.

For example: Bill O'Reilly, host of Fox News Cable channel program, The O'Reilly Factor, three times between July, 2001 and March, 2002, stated on his program: "No one knows when human life begins".

Two years ago, when the public debate centered around culturing early human embryos in a petri dish, Senator Orrin Hatch and former Senator Connie Mack both said: "it's not a human life until it is in the uterus" 1.

The lead editorial in the Arizona Daily Star of 26 January, 2003 states: A bill affirmed by the State Judiciary Committee requiring the gestational age of the unborn child be given to a woman before an abortion, was an "attempt to answer the emotionally charged question of when life begins". It also said "the bill is yet another attempt to convert a private medical issue into a moral and religious one".

USA Today reported on 24 January, 2003 that Amy White, who writes monthy commentaries for the St. Louis Post Dispatch, stated in an article about the 30th anniversary of Roe v. Wade: ". . .how can we navigate our way through the moral minefields . . . when we're still unsure when life begins?"

Duncan Hunter, California Congressman, is set to introduce a bill that declares "life begins at conception". Although such a bill has been introduced before, the issue has never come up for a vote.

Some state legislatures are considering similar action, e.g. New Hampshire. State Representative Barbara Hagan introduced her bill stating: "life begins at fertilization". Yet, opposing that bill, Representative Peter Allen, Democrat, declared it is still a matter of semantics as to when life begins. Another opponent, Democrat Representative Frances D. Potter, claimed the bill was "grounded in religion".

On 27 February, 2003, the U.S. House of Representatives passed a ban on human cloning. USA Today reported the next day on the vote and stated: "Some scientists . . . argue that tiny cloned embryos . . . are not the same as a human being. But opponents [to cloning] argue that the tiny cells are an individual life".

Thus, it is very clear that in the past 30 years the question as to when human life begins has not been resolved for much of the general public. It is also very clear that there are legions of pols and pundits who are totally refractive to scientific fact.

Further, it is unfortunate, but true, that much of the lay public has little background in basic reproductive biology, and even less in Human Embryology. As a consequence, this basic information has been rather easily corrupted within the public discourse.

The Science of Human Embryology

Hippocrates (460-377 B.C.) wrote about the development of the chick embryo. Later, Aristotle (384-322 B.C.) wrote a treatise on his observations of development of the chick embryo and other embryos. He is generally regarded as the "founder" of embryology. Subsequently, there were many published observations of embryonic and fetal development, including drawings of a dissected pregnant uterus by Leonardo da Vinci (15th century, A.D.), albeit with certain errors.

The invention of hand lenses and the microscope facilitated studies of the chick embryo by Marcello Malpighi (1628-1694), but also gave rise to one of the most profound errors in describing human development, that of the homunculus. This was a miniature human believed to have been seen within the head of a human spermatozoon and which presumed to enlarge when deposited in the female. This was the basis of the preformation theory and was believed by many well into the 18th century.

Eventually, this theory gave way to that of epigenesis, that is, the individual arose incrementally during development by way of "globules" or tissues developing and growing upon a preexisting "globule" or tissue. The cell theory developed by Schleiden and Schwann in 1839 hastened our knowledge of embryology and provided for the realization that a spermatozoon fuses with an oocyte ("egg") and forms a zygote, the single celled embryo, which then divides and adds more cells and tissues in defining the developing body.

Wilhelm Roux, Hans Spemann, winner of the Nobel prize in 1935, and others continued many experiments on invertebrates and lesser vertebrates and formed the basis for the science of experimental embryology, or, today recognized as developmental biology.

However, paraphrasing Pierre Charron (1541-1603), the proper study of mankind is man. The father of human embryology is generally regarded as Wilhelm His (1831-1904). He developed the method of reconstruction, that is, putting together descriptive drawings from sectioned human embryos to show a three dimensional structure.

Although the case for fertilization of the human oocyte by the human spermatozoon was made intuitively by observing the process in mammals more than 100 years ago, direct observation of the process in the human was made in about 1968. The significance of this was resolved experimentally with subsequent growth of the new individual and successful implantation with completion of development to birth. This was accomplished with the birth of baby Louise Brown in England in July, 1978. Other successes soon followed.

The Continuum of Life

The facts above, along with the constancy of the time of gestation, approximately 38 weeks, reasonably declare that the life of the new individual human being begins with fertilization. Virtually every human embryologist and every major textbook of Human Embryology states that fertilization marks the beginning of the life of the new individual human being.

The reason why this is true is the following:

from the moment when the sperm makes contact with the oocyte, under conditions we have come to understand and describe as normal, all subsequent development to birth of a living newborn is a fait accompli. That is to say, after that initial contact of spermatozoon and oocyte there is no subsequent moment or stage which is held in arbitration or abeyance by the mother, or the embryo or fetus. Nor is a second contribution, a signal or trigger, needed from the male in order to continue and complete development to birth. Human development is a continuum in which so - called stages overlap and blend one into another. Indeed, all of life is contained within a time continuum. Thus, the beginning of a new life is exacted by the beginning of fertilization, the reproductive event which is the essence of life.

Herein lies the importance of distinguishing between the science of developmental biology and the science of Human Embryology. Within the science of Human Embryology, the continuum of life is more fully appreciated. The fact that development and developmental principles do not cease with birth becomes more fully realized. So, the continuum of human development does not cease until death, whenever that may occur, in utero or at 100 years of age.

The Basic Terminology

For the lay person it is not important to remember embryological terms, or study their greek origins, for two reasons: 1. It is the continuum of life which is important as a biological fact, and 2. even human embryologists continue to discourse and refine our language. The terminology of Human Embryology is important only in the taxonomic sense. This terminology enables human embryologists to talk to one another. It is also important in the same way to some Obstetricians and Pediatricians. However, for the record, the following terms have virtually all been abused in media articles and the public discourse of the many socio - legal issues, including Congressional hearings. So, a quick review is necessary to identify those terms so abused.

When the sperm fuses with the secondary oocyte fertilization takes place. This fusion eventually produces a single cell but with two pronuclei, each one containing either the maternal or the paternal chromosomes. The former are provided by the oocyte and the latter by the sperm. These pronuclei come together to reconstitute the proper number of chromosomes for our specie (called diploid), which is 46 chromosomes, including 2 sex chromosomes. From this coming together the single cell divides into two cells, and division continues until a cluster or ball of cells is formed called the morula. Soon thereafter, the cells in the morula divide and cluster so that a small cavity is formed, above which is a mass of cells. This is called the blastula, and when the cavity becomes larger the embryo is called the blastocyst and the mass of cells above it is called the inner cell mass or the ICM. Other events have taken place since fertilization, especially movement of the embryo down the fallopian tube, assumming fertilization has taken place in the upper third of the tube, which is optimal, so that the embryo is positioned properly within the uterus and ready for implantation. This takes 5 to 6 days. The outer rim of cells of the embryo has special properties allowing it to "invade" the lining of the uterus. Among the many simultaneous events occurring are changes in the cells of the embryo which "regulate" its destiny. Such regulation actually began at probably the first cell division of the embryo when an unusual but significant production of an immunosuppresant takes place, the early pregnancy factor. This prevents rejection of the "foreign" embryo by the mother.

In addition, the "regulation" taking place among the cells of the early embryo has to do with communications between the cells, which allow for movement of materials, providing signals or directions to a cell or cells prompting them to divide or not to divide, or to respond in general or specific ways which can direct their destiny or potentials.

One often hears the rallying cry from prochoice advocates: "my body, my choice". Certainly, they exercise a choice, but, it is not just "my body". There are two2 bodies, each genetically distinct, and each "foreign" to the other. It should be recognized that the body of the early embryo is very active in its daily rituals of survival.

Prior to about 14 days post-fertilization the embryo becomes composed of two layers, an upper or epi - layer, and a lower or hypo - layer. At 14 days a third layer appears wedged inbetween the upper and lower layers. At this time the cells of this third layer are dividing and the direction of movement of those cells is mostly toward the cranial end of the embyro, but also a lesser number and movement toward the caudal end of the embryo. This division and movement of the cells produces a primitive streak. Subsequently, the shape and form of the embryo change dramatically. Such phenomena as bending, folding and pleating sculpture the embryo into a more definitive form. This is largely brought about by differential proliferation. In other words, some cells, or groups of cells divide faster or slower than others. This changes the appearance and form of the embryo.

Every moment of development blends into the next succeeding moment. But, even common sense tells one that this so-called development does not cease at birth. It continues until death. At any point in time, during the continuum of life, there exists a whole, integrated human being. This is because over time from fertilization to a 100 year old senior, all of the characteristics of life change, albeit at different rates at different times: size, form, content, function, appearance, etc.


Human embryologist Bruce Carlson, in his 1994 textbook: "Human Embryology and Developmental Biology", states in his opening sentence: "Human pregnancy begins with the fusion of the egg and the sperm. . ."[2]. This is so because the concern of Human Embryology is the human embryo whether it be in the fallopian tube, uterus, ectopically placed or in a petri dish. Additionally, for a pregnant woman, the expected time of delivery, fertilization age, time of gestation, or, the period of confinement is always calculated so that the time of pregnancy begins at fertilization.

The idea that pregnancy begins at implantation of the embryo in the uterus was generated more than 3 decades ago. At that time there were concerns about the actions of chemical contraceptives. Albert Rosenfeld wrote in his book: "Second Genesis" (1969):

Because these substances do not prevent the sperm from penetrating and fertilizing the ovum - the classic definition of conception - they are not strictly contraceptives. What they do is prevent the newly fertilized egg from implanting itself in the uterus. Since the interference occurs after conception, some hold that such practice constitutes abortion. A way around this impasse has been suggested by Dr. A.S. Parkes of Cambridge: Equate conception with the time of implantation rather than the time of fertilization - a difference of only a few days" 3 (my emphasis). Thus, a fact of science gave way to political correctness.

The Corruption of The Science of Human Embryology

How did the basic fact of when human life begins, and other facts about human development become so parsed, changed and corrupted? For the answer to that we have to look at what actually happened within the Supreme Court of The United States in 1973.

The Supreme Court:

Roe v. Wade

The modern day assault on Human Embryology began in 1973 in the oral arguments of Roe v. Wade, and in the majority opinion written by Justice Harry Blackmun4. He wrote: "We need not resolve the difficult question of when life begins". He referred to the "disciplines of medicine, philosophy and theology" as being "unable to arrive at any consensus". It appeared he was talking about biological life by inferring that "medicine" could define its beginning. But, then, Blackmun said the following: "There has always been strong support for the view that life does not begin until live birth. This was the belief of the Stoics." This was as if to say that science had not progressed since 300 B.C.

Clearly, Blackmun conflated biological life with philosophical life, even though biological life, per se was never referenced in his decision.

During oral arguments, in the second hearing before the Supreme Court, Robert Flowers, arguing for appellants, clearly stated the position of the State of Texas: "Human life begins at conception and is present throughout pregnancy." However, Justice Blackmun then asked Flowers if that was "a medical question"? Flowers then compromised his position by legitimizing Blackmun's restating Flowers' statement as a question, and said it (referring to the now accepted question when it was not a question at all) should be decided by "a legislative decision". In one fell swoop Flowers destroyed the scientific base of his testimony.

Then, Justice Marshall said: "I want you to give me a medical, a recognizable medical writing of any kind that says that at the time of conception the fetus is a person." Flowers responded: "I do not believe I could give that to you without researching through the briefs that have been filed in this case, your honor."

Clearly, Robert Flowers was not prepared to argue the biological life of the new individual human being, or to force the Justices to be consistent and cogent with their questions and/or statements.

In this case, was the behavior of the Supreme Court Justices disingenuous, intellectually dishonest or just plain ignorant? Asking a question like this seems to apply a label of opprobrium; but, if so, it is richly deserved because the facts of science were readily available to the Justices who are staffed with an army of law clerks and assistants who could easily have obtained the vital scientific facts.

Webster v. Reproductive Health Services of Missouri

In the Webster case, adjudicated in October, 1988, an amici curiae brief of 167 distinguished scientists and physicians, including 11 Nobel Laureates, wrote in their summary of argument: "There is no scientific consensus that a human life begins at conception, at a given stage of fetal development, or at birth"! Not only is such a declaration outrageous, it is tantamount to 'The Big Lie'. How were these 167 chosen, and who were they? Susan Solomon, a graduate student at the University of Arizona College of Medicine, researched this group and concluded that NOT A SINGLE ONE was a human embryologist5.

Stenberg v. Carhart

In Stenberg v. Carhart, the Nebraska partial birth abortion case, adjudicated in June, 2000, no less than five (5) Justices used, acknowledged and endorsed the phrase "potential human life" in their written opinions6. This phrase had appeared in Blackmun's decision of Roe v. Wade in 1973. Twenty seven years later it remained certified.

In simple terms, human life is never potential. Life is life. A life that is not living, is dead. The conflation continues. The Justices infer a biological quality when they speak about the birthing, or partial birthing of the fetus, but then enjoin that with such quasi-legal terms as "person" and conclude that "life is potential".

They cannot avoid being compared to a similar decision made in Nazi Germany in the 1930s that some human life was subhuman, untermenschen; Lebens unwertenleben - lives unworthy of life.

Clearly, the revision of the science of Human Embryology began with Blackmun's decision in the Roe v. Wade case. In spite of volumes written to correct the errors, Blackmun's declaration has prevailed and given rise to a plethora of other revisions, some of them so egregious as to defy all common sense and recorded fact to the contrary.

Next Page: The Wrong Scientists Are Talking About The Human Embryo
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