Professor Lee Silver wrote an article in the Washington Post, August 19th, 2001, entitled: “Watch What You Are Calling An Embryo”. It is supposed to be about Human Embryology, a subject in which he has dubious qualifications.
This is not unusual; since 1973 pols and pundits have written and spoken about Human Embryology as though they were experts. In fact, the media has virtually excluded human embryologists as a source for information about the core issues of Human Embryology, including: abortion, partial birth abortion, fetal tissue research, human embryo research, cloning, stem cell research and other related issues.
In this critique I have commented on his article as my remarks pertain to the science of Human Embryology. My qualifications for doing so are a B.S. degree in Biology, Master’s and Ph.D. degrees in Experimental Embryology, and a 35 year career in Human Embryology, teaching the subject to medical students, upper division and graduate students in the medical schools in Galveston, Texas and Tucson, Arizona. I also established one of the largest museums of human embryos and fetuses in the country.
C. Ward Kischer, Ph.D.
emeritus professor of Anatomy
University of Arizona
College of Medicine
Tucson, Arizona
For the past ten years the public has been progressively drowning in a near psychotic assault on the english language, and common sense, through double talk, distortions, convolutions, parsing and biobabble. Now comes Professor Silver to further muddy the waters with a claim that words like “embryo”, “life” and “death” are “ambiguous”.
Life as a process began when the first molecular replication became sustained into the unbroken chain which we have today. It is called the continuum. Somewhere along that chain the process for humans became refined into sexual reproduction and the fusion of male and female sex cells fused to renew that continuum by forming a new individual human life.
That is Biology 101. It is also the first thing learned in Human Embryology: that the life of the new individual human being begins at fertilization (conception). Professor Silver received a Ph.D. degree in biophysics. Apparently, he is a self-made molecular biologist. He should know basic biology, probably not basic Human Embryology, but, every textbook in Human Embryology states when the new individual human life begins. Even the ancients knew intuitively about this, as the Bible speaks of semen as “seed”. Hippocrates certainly knew about the value of human life when he included in his Oath the prohibition of “using a pessary to produce an abortion”.
When animal experiments were done in the 18th and 19th centuries, deductive reasoning led to the conclusion that life began at conception; and, finally, this was observed directly by the first in-vitro fertilization procedures with human gametes some 40 years ago. So, the question is: why does Silver assault these self-evident truths? Since a reasonable assumption is that he has been through basic biology, and that he is not going to be able to rewrite its entire history, the answer must lie elsewhere. There are some absolutes in this world, and when the life of the new human being begins is one of them.
In our present time, it seems that If one wants to believe that up is down, north is south, right is wrong, all that is required is for someone to say so. But, somehow, that nagging little thing called the truth always seems to have a way of turning up like a bad penny.
Silver tries to define a “stem cell”; but, he does so without the slightest reference to its real history.
The term “stem cell” was coined by histologists, not human embryologists. In fact, this term has just appeared in the textbooks of Human Embryology in the last decade. The term describes a cell found in most tissues of the body, as a companion cell to the differentiated cells in a given tissue. The stem cell is there to renew lost cells through general attrition and wear, and to repair damaged tissue. Somehow, molecular biologists and biological engineers have applied this term to the early embryo and to the undifferentiated state of the early blastomeres (cells).
But, caution must reign. Human embryologists, so far, are not embracing this term for the cells of the early embryo. There is a good reason for this. The cells of the early embryo are not the same as the “adult stem cells”. The latter are determined, but not terminally differentiated. The cells of the early embryo are “regulated”; but, we cannot, as yet, measure what this really means. Further, these early embryonic cells are connected to their neighbors and communications are going on. We do not know what this means in terms of “determination” or “regulation”. It is presumed that they have the “potential” to differentiate into any cell or tissue type. But, that can be a stretch. We simply do not know.
Silver uses a confusion of terms. First of all, Silver uses the term “egg”. There is no such cell in the human. The sperm fuses with an “oocyte”, in point-of-fact, a stage of a “secondary oocyte”. An “egg” or an “ovum” do not exist in the human.
Silver says: “The cells on the inside of the embryo are the ES (embryonic stem) cells”. The truth is that no human embryologist makes this claim. These cells “on the inside” are called “the inner cell mass” (if a blastocyst is the stage he is referring to). The reason they should not be called ES cells (embryonic stem cells) is because we really do not know in what metabolic, differentiated, and regulatory state they are in! The first question to ask is: are the ES cells the equivalent of the Adult stem cells? The answer is: we do not know. A very few reports, to date, “suggest” that they might be. But, it is going to be a long time before we determine if there is any real equivalency.
Silver refers to the inner cell mass cells with the comment that “They and they alone will grow into the fetus and child. What Silver does not apparently know is that there is a sharing of derivatives from “outside” tissues and “inside” tissues during development. The real point is that they act reciprocally to promote development of the embryo and fetus.
Silver claims that the ES cells can be “coaxed into making a whole human body”. The real answer is: “Nobody knows”. But, to propose such an outcome one first has to consider that the ES cell would be programmed to produce its double, as in monozygotic twinning. However, these so-called ES cells, assummedly taken from the blastocyst, or inner cell mass, if in the state of being able to “split” and form a double, would account for only 0.22% of all live births (in the U.S.). We presently do not know why splitting into MZ twins occur. Nor do we know when it no longer can occur.
Retrospectively, we know that of those MZ twinning cases that are born, one-third of them split early in development, two-thirds late in development. It could be significant that no reports to date have indicated MZ twins born from IVF implants.
So, it is a bit irresponsible to propose, as Silver does, that any ES cell could be “coaxed” into producing a whole new body. We simply do not know.
Silver likes to compare research findings in mice to those in humans. But, a mouse is not a human. To my knowledge a mother mouse never gives birth to a single mouse. But, in the human, it happens in 99.78% of all live births. I suggest Silver revisit his Biology 101.
Referring to the frozen “spare” embryos in IVF labs, Silver makes the outrageous claim that “ES cell research won’t actually destroy these embryos”. Here we go again – up is down, right is left, north is south! He further states: “lives will be saved without any lives being lost”! Well, it all depends on what the meaning of “is” is. “Lives” are not really lives, they are Untermenshen! Rarely is it mentioned in this type of discourse that what Silver says is a rebirth of Lebens Unwertenleben. Only he gives it a new twist by claiming that no “lives” will be lost!
Silver claims: “without a clear definition of “life”, the question of respect is meaningless.” Wonderful! One of the best ways to “win” an argument is to erect a straw man, then proceed, methodically, to knock him down. Never mind the methods, just confound the senses with one outrageous claim after another.
He refers to the human embryo as: “A ball of cells smaller than a pinhead” — Lee Silver, Professor at Princeton, “[A spare embryo] no bigger than the period at the end of this sentence” — William Safire, syndicated columnist. “A tiny mass of cells. . .” — David Baltimore, President of Cal Tech and a Nobel Laureate. “[The spare embryo] so small that it can fit on the tip of a sewing needle” — Dr. Mary Hendrix, President of FASEB, and Head, Dept. of Anatomy, University of Iowa, College of Medicine.
Does this mean that small people are less significant, or less human, than big people? Do these people really know what they are saying? What profound arrogance! One of the basic concepts of development that these people, and many others, do not understanc, or wish to understand, is the following: Over time, the qualities of life change – size, form, function and appearance. We can reduce any point in time to a trivial value by comparing that point to any other reference point one might choose. And, in fact, this is exactly what was done by the Nazis in the 1930s. They did it on the basis of race and ethnicity. Here, today, it is being done on the basis of size.
Silver invokes the word sentient and indirectly uses it to define a “life”. Sentience is not a scientific word. It is born out of psychology. It is also very arbitrary. Thus, Peter Singer justifies his endorsement of infanticide by claiming that new-born individuals are not “sentient” until up to three months after birth. That may be correct, depending on one’s definition of sentience. But, too, the newborn is “so small”! Also, it cannot answer back.
Silver is applying extramural “characteristics” to the reality of Life. Grobstein tried this, with great success, by inventing a “stage” of human embryological development called the “preembryo”, but tried to give this “stage” scientific credibility by correspondingly applying nonscientific justifications. It didn’t work. No human embryologist accepts his inventions. Grobstein’s justifications were (1) sentience, which is arbitrary, (2) appearance, that is when “others” could recognize the embryo as “human”! and (3) individuation, a term he used to indicate that the embryo up to 14 days could split into MZ twins. Thus, a single human being could not be present up to that time.
Silver is being esoteric; but, that is what one does to confound and confuse others whom he is trying to convince. He equates cellular human life – shedding skin cells – with a “microscopic human embryo”! and asks why should one respect the human embryo (if they are the same as shedding skin cells)? Why indeed. It is “so small”! Silver is progressively proving me wrong when I claimed that he knew Biology 101. We should respect a microscopic human embryo because at that time it is an integrated whole organism, just as the human is at every moment in time until death. Every human embryo deserves as much respect as you or I because it is formed as a new individual human life within the continuum of life as a manifestation of NATURAL LAW!
Silver states that animal experiements in which “stem” cells have been redifferentiated is really “cloning”. This is utter nonsense. Silver obviously knows virtually nothing about cloning. The original (modern) cloning experiments were performed in 1953 by Briggs and King. They were discovering nuclear potential and in the process produced “exact copies”. What Silver has described above is called “de-differentiation” or “re-differentiation”.
I would suggest that before Silver throws wild expectations around anymore that he consult the recent literature concerning the anomalies and defects now being discovered in cloned animals, using ADULT nuclei for transfers. Even when Briggs and King were performing their experiments they found defects and death occurring from transfer of embryonic nuclei. It may well be that the “mother of all molecular-conversion keys” may get broken off in the lock. Silver’s rhetoric really belongs in the grocery store tabloids. If he wants credibility in science he should stick to science where his ideas can be reviewed and critiqued.
Silver’s essay is consistent with what has been promoted for the past 29 years: a trivialization and corruption of the science of Human Embryology. I highly recommend a basic Human Embryology course for Professor Silver. In addition I wish to remind him of an admonition he has demonstrated to be so proud of: Watch What You Are Saying About The Human Embryo!
Release issued: 28 Jan 02
