Skip to comments.The Facts of When Human Life Begins--Interview With Dr. Maureen Condic (Excellent Reference)
Posted on 02/02/2009 8:23:19 PM PST by cpforlife.org
SALT LAKE CITY, Utah, NOV. 7, 2008 (Zenit.org).- The conclusion of scientist Maureen Condic that human life begins at a defined moment of conception isn't an opinion based on a belief, but rather a "reflection of the way the world is."
Condic, a senior fellow of the Westchester Institute for Ethics and the Human Person, published her conclusions in a white paper titled "When Does Human Life Begin?" In the report she addresses the topic using current scientific data in human embryology.
An associate professor of neurobiology and anatomy at the University of Utah School of Medicine, Condic received her doctorate in neurobiology from the University of California, Berkely. Her teaching focuses primarily on embryonic development, and she directs the University of Utah School of Medicine's course in human embryology.
In the interview with ZENIT, Condic explains why the question of when human life begins is important to address, and what scientific criteria she used to define a "moment of conception."
Q: This is the first white paper for the Westchester Institute. Why this topic? Why now?
Condic: This is an important question, with significant biological, ethical and philosophical dimensions. As I note in the paper, resolving when human life begins has important implications for a number of controversial political topics, including abortion and human embryonic stem cell research.
As a scientist and as director of a medical school course in human embryology, I have been considering the general question of when human life begins for quite a few years. The argument put forward in the white paper has grown out of discussions with philosophers, scientists and ethicists, as well as out of my own research in this area.
Yet this topic has come to the fore in the lead-up to the presidential election. While the topic of when life begins has generally been avoided by politicians and government officials, recently a number of prominent figures have offered their interpretations, making this a timely subject to consider with scientific rigor and neutrality.
Q: You define the moment of conception as the second it takes for the sperm and egg to fuse and form a zygote. What were the scientific principles you used to arrive at this conclusion?
Condic: The central question of "when does human life begin" can be stated in a somewhat different way: When do sperm and egg cease to be, and what kind of thing takes their place once they cease to be?
To address this question scientifically, we need to rely on sound scientific argument and on the factual evidence. Scientists make distinctions between different cell types (for example, sperm, egg and the cell they produce at fertilization) based on two simple criteria: Cells are known to be different because they are made of different components and because they behave in distinct ways.
These two criteria are used throughout the scientific enterprise to distinguish one cell type from another, and they are the basis of all scientific (as opposed to arbitrary, faith-based or political) distinctions. I have applied these two criteria to the scientific data concerning fertilization, and they are the basis for the conclusion that a new human organism comes into existence at the moment of sperm-egg fusion.
Q: Many in the scientific world would say that fertilization doesn't happen in a moment, but rather that it is a process that comes to an end at the end of the first cell cycle, which is 24 hours later. Why is it important to define a "moment of conception," as opposed to a "process of fertilization"?
Condic: It is not important to somehow define a "moment" or a "process" of fertilization in the abstract. It is important to base conclusions and judgments about human embryos on sound scientific reasoning and on the best available scientific evidence.
Had this analysis led to a different conclusion -- for example, that fertilization is a "process" -- I would have accepted this conclusion as scientifically valid. However, a scientific analysis of the best available data does not support the conclusion that fertilization is a "process"; it supports the conclusion that fertilization is an event that takes less than a second to complete.
The events of the first 24 hours following sperm-egg fusion are clearly unique, but they are also clearly acts of a human organism, not acts of a mere human cell.
Q: Do opinion, belief and politics have a place in defining the beginning of a new life? How is it that the topic has become an issue of debate?
Condic: The topic of when human life begins is an issue of debate because it has strong implications for public policy on matters that concern many people; abortion, in-vitro fertilization and human embryo research. How "opinion, belief and politics" have assumed such a large role in deciding when life begins is a question for a sociologist or a psychologist, not a biologist!
It is important to appreciate that the scientific facts are themselves entirely neutral; they are simply a reflection of the way the world is, as opposed to how we may wish or imagine it to be.
That is not to say that the scientific facts lend equal support to any and all views of when human life begins. While people are free to formulate their opinion on when human life begins in any manner they choose (including belief and politics), not all opinions are equally consistent with factual reality. Those who choose to ignore the facts cannot expect their opinions to garner as much respect or to be given as much credibility as those who base their opinions in sound scientific observation and analysis.
The opinions of members of the flat-Earth society should not carry as much weight as those of astrophysicists in formulating national aerospace policy. The opinions of those who reject the scientific evidence concerning when life begins should not be the basis of public policy on embryo-related topics, either.
Q: Who needs to read this paper and why?
Condic: I think every person who is concerned about the important "life-issues" of health care, abortion, assisted reproduction and stem-cell research should read this article, because understanding when life begins is the basis of a sound political, ethical and moral debate on these complex and difficult topics. Certainly, all those charged with the formation of public policy on these matters should read this argument and think seriously about its implications. If we cannot know what a human embryo is and when it comes into existence, we cannot make sound judgments regarding any of the issues surrounding the human embryo.
Q: What reactions have you received to the conclusions of your paper? What do you hope will result from its publication?
Condic: Thus far, reactions have been thoughtful and considered. I hope this will continue and that a clear understanding of the relevant scientific evidence will help ground future public policy debates over embryo-related issues in sound scientific fact -- rather than in mere "opinion, belief and politics."
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On the Net:
White Paper. When Does Human Life Begin?
Don’t the sperm and egg cells, before fertilization, have life too?
Conclusion: Abortion is murder and “Choice” is a mountain of lies.
They are potential life, which is why spilling seed was considered sin as well
Please FreepMail me if you want on or off my Pro-Life Ping List.
ONE NATION UNDER GOD
“Potential” life is muddying the meaning. The cells are individually alive, as well. We can have live sperms, and we can have dead sperms. So too, with eggs.
Special PING M.
I think you’ll find the White paper at the link very good.
READ AND COMPREHEND.
NOV. 7, 2008.
That’s when the article came out.
You don’t believe FR to be the only source, do you?
Besides, I didn’t find my query addressed in the article. Perhaps you would like to point it out to me?
Sperm and egg cells are “alive” in only a very limited sense. Neither can survive for any length of time in their natural environment, and neither can perform most of the normal functions of other human cells. They cannot receive nutrients or excrete waste, and they cannot perform cell division, which is the critical characteristic of life.
But once made whole by merging their two complementary parts, they follow an innate, complex program that, if they survive this first, most perilous journey to their natural but temporary home, connected intimately to their nurturing mother for the months needed to prepare them for the world we live in.
Neither sperm nor egg, by itself, could ever become what the two of them together will be, or do by itself what they are fully prepared to do together.
Actually, they can. Fructose is a component of semen. Eggs have a yolk sac.
Limited or not, egg and sperm have life.
Bump for life!
A sperm is not a stage of human life, neither is an egg.
I was never just a sperm, nor was I ever just an egg.
I was however once zygote.
Were the sperm and egg from which you derive your entire genetics, living or non-living?
It doesn’t matter how you qualify them, we’re talking specifically about human life.
Yes, and I’m talking about a human egg and a human sperm, which specifically leads to a zygote and becomes a human. None of the stages starting with the egg and the sperm, were non-living.
BTW, thanks for the ping, Kevin.
Asking when life begins is the wrong question because the material involved is never “dead” (dead things don’t spring magically to life). The question is when a new individual begins.
bump bump bump
a thousand times bump
Yeah, so what.
So, no one can really say when life began, because it is a chain of life that brings about new humans. No part of the time preceding the beginning of human existence, was non-living. So, life really doesn’t “begin”. It just is.
But the title is not about when the individual begins; it's literally abit when human life begins. In reality, there is no "beginning of human life". It's a chain.
It’s not as simple as that. Human life does not have a sharp beginning, as does individual existence. The chain of life is unbroken, for each human to be born.
“No part of the time preceding the beginning of human existence, was non-living”
When does a human come into existence?
You don’t want it to be that simple, but it is. You are purposely conflating organ with organism. It’s not unusual for those trying to defend killing the alive unborn. A zygote is an organism; a spermatazoon is a sub unit formed in an organ of an organism. Denial doesn’t chnage reality.
There is a difference between human life and an individual human being. Your cells are alive but they aren’t human beings. A zygote, is, in fact, a living human being.
Yes. The title mentions human life.
Perhaps. But we can certainly point to the time that an individual human being comes into existence. Slick language can only serve to obscure the facts, it can not change them.
That would be the author’s error. She left an opening for sophisters to do their thing. That does not, however, alter the fact that an individual human being comes into existence at the time of conception.
If conception is the entry of the sperm into the egg alone, then that is not the point where the individual human being comes into existence. It takes several biological stages for the nuclear elements of the sperm to get fully involved with the nuclear elements of the egg. This takes about 16-18 days after the sperm has entered the egg.
Lets get to the point. Are you for or against abortion?
Everything so far looks like you are trying to rationalize in favor of abortion through the employment of semantic gymnastics.
The wording in the article might not be absolutely perfect, though the facts remain the same.
Every medical text on the subject states clearly that the life of an individual human being begins at their conception.
More info on this irrefutable scientific fact:
Read the whole thing then please get back to me.
What does modern science conclude about when human life begins? (Excerpts)
By Dr. John Ankerberg and John Weldon
The complete article is available in print friendly PDF format at: http://www.ankerberg.com/Articles/_PDFArchives/apologetics/AP3W0805.pdf
The scientific authorities on when life begins are biologists. But these are often the last people consulted in seeking an answer to the question. What modern science has concluded is crystal clear: Human life begins at conception. This is a matter of scientific fact, not philosophy, speculation, opinion, conjecture, or theory. Today, the evidence that human life begins at conception is a fact so well documented that no intellectually honest and informed scientist or physician can deny it.
In 1973, the Supreme Court concluded in its Roe v. Wade decision that it did not have to decide the “difficult question” of when life begins. Why? In essence, they said, “It is impossible to say when human life begins.” The Court misled the public then, and others continue to mislead the public today.
Anyone familiar with recent Supreme Court history knows that two years before Roe V. Wade, in October 1971, a group of 220 distinguished physicians, scientists, and professors submitted an amicus curiae brief (advice to a court on some legal matter) to the Supreme Court. They showed the Court how modern science had already established that human life is a continuum and that the unborn child from the moment of conception on is a person and must be considered a person, like its mother. The brief set as its task “to show how clearly and conclusively modern scienceembryology, fetology, genetics, perinatology, all of biologyestablishes the humanity of the unborn child.” For example,
In its seventh week, [the pre-born child] bears the familiar external features and all the internal organs of the adult.... The brain in configuration is already like the adult brain and sends out impulses that coordinate the function of other organs . The heart beats sturdily. The stomach produces digestive juices. The liver manufactures blood cells and the kidneys begin to function by extracting uric acid from the childs blood.... The muscles of the arms and body can already be set in motion. After the eighth week everything is already present that will be found in the full term baby.
This brief proved beyond any doubt scientifically that human life begins at conception and that “the unborn is a person within the meaning of the Fifth and Fourteenth Amendments.”
Thus, even though the Supreme Court had been properly informed as to the scientific evidence, they still chose to argue that the evidence was insufficient to show the pre-born child was fully human. In essence, their decision merely reflected social engineering and opinion, not scientific fact. Even during the growing abortion debate in 1970, the editors of the scientific journal California Medicine noted the “curious avoidance of the scientific fact, which everyone really knows, that human life begins at conception and is continuous whether intra- or extra-uterine until death.”
In 1981, the United States Congress conducted hearings to answer the question, “When does human life begin?” A group of internationally known scientists appeared before a Senate judiciary subcommittee.
The U.S. Congress was told by Harvard University Medical Schools Professor Micheline Matthews-Roth, “In biology and in medicine, it is an accepted fact that the life of any individual organism reproducing by sexual reproduction begins at conception....”
Dr. Watson A. Bowes, Jr., of the University of Colorado Medical School, testified that “the beginning of a single human life is from a biological point of view a simple and straightforward matterthe beginning is conception. This straightforward biological fact should not be distorted to serve sociological, political or economic goals.”
Dr. Alfred Bongiovanni of the University of Pennsylvania Medical School noted: “The standard medical texts have long taught that human life begins at conception.”
He added: “I am no more prepared to say that these early stages 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 albeit incomplete until late adolescence.”
Dr. McCarthy De Mere, who is a practicing physician as well as a law professor at the University of Tennessee, testified: “The exact moment of the beginning [of] personhood and of the human body is at the moment of conception.”
World-famous geneticist Dr. Jerome Lejeune, professor of fundamental genetics at the University of Descarte, Paris, France, declared, “each individual has a very unique beginning, the moment of its conception.”
Dr. Lejeune also emphasized: “The human nature of the human being from conception to old age is not a metaphysical contention, it is plain experimental evidence.”
The chairman of the Department of Medical Genetics at the Mayo Clinic, Professor Hymie Gordon, testified, “By all the criteria of modern molecular biology, life is present from the moment of conception.”
He further emphasized: “now we can say, unequivocally, that the question of when life begins is an established scientific fact . It is an established fact that all life, including human life, begins at the moment of conception.”
This Senate report concluded:
Physicians, biologists, and other scientists agree that conception marks the beginning of the life of a human beinga 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.
In 1981, only a single scientist disagreed with the majoritys conclusion, and he did so on philosophical rather than scientific grounds. In fact, abortion advocates, although invited to do so, failed to produce even one expert witness who would specifically testify that life begins at any other point than conception.
Again, let us stress that this is not a matter of religion, it is solely a matter of science. Scientists of every religious view and no religious viewagnostic, Jewish, Buddhist, atheist, Christian, Hindu, etc.all agree that life begins at conception. This explains why, for example, the International Code of Medical Ethics asserts: “A doctor must always bear in mind the importance of preserving human life from the time of conception until death.”
This is also why the Declaration of Geneva holds physicians to the following: “I will maintain the utmost respect for human life from the time of conception; even under threat, I will not use my medical knowledge contrary to the laws of humanity.” These statements can be found in the World Medical Association Bulletin for April 1949 (vol.1, p. 22) and January 1950 (vol. 2, p. 5). In 1970, the World Medical Association again reaffirmed the Declaration of Geneva.
What difference does it make that human life begins at conception? The difference is this: If human life begins at conception, then abortion is the killing of a human life.
To deny this fact is scientifically impossible.
Abortion Statutes of the 19th & 20th Centuries (excerpts) http://www.missourilife.org/law/preroe.htm
During the first decades of the 1800’s, scientists began to understand the cellular basis of life and for the first time were able to observe the process of fertilization in mammals. As the stages of development became clear, it also became clear that abortion kills a living human being, no matter what the stage of the child’s development.
The resulting scientific knowledge about the process of conception and development led to efforts to enact stronger bans on abortion. In addition, scientific progress allowed for surgical means of performing abortion, and abortion was perceived to be on the increase. Beginning in 1859, the American Medical Association called for strong anti-abortion laws and vigorous enforcement of them. In view of the claim by twentieth century abortionists that physicians did this only to protect their own profession or solely to protect women’s health, it is useful to quote the doctors themselves on why they wanted action by the states:
“The first of these causes is a wide-spread popular ignorance of the true character of the crime—a belief, even among mothers themselves, that the foetus is not alive till after the period of quickening.
“The second of the agents alluded to is the fact that the profession themselves are frequently supposed careless of fetal life; . . .
“The third reason of the frightful extent of this crime is found in the grave defects of our laws, both common and statute, as regards the independent and actual existence of the child before birth, as a living being.
“In accordance, therefore, with the facts in the case, the Committee would advise that this body, representing, as it does, the physicians of the land, publicly express its abhorrence of the unnatural and now rapidly increasing crime of abortion; that it avow its true nature, as no simple offence against public morality and decency, no mere misdemeanor, no attempt upon the life of the mother, but the wanton and murderous destruction of her child. . “ Volume 12, Transactions of the American Medical Association, pp. 75-78 (1859).
The AMA adopted the recommendation described above and sponsored initiatives in all states, spurring most legislatures to enact strong prohibitions upon abortion that swept away the “quickening” distinction. In the remaining states, abortion remained prohibited by common law.
A BRIEF SURVEY OF US ABORTION LAW BEFORE THE 1973 DECISION
by Brian Young (excerpts) http://www.ewtn.com/library/PROLIFE/LIFBFROE.TXT
Pro-abortion historians claim that these laws were passed primarily, if not solely, to protect women from possibly fatal abortions. Concern for pre-term babies was not a factor, they claim. Yet, as law professor Joseph Dellapenna has noted, all surgeries at that time involved substantial risks of death. If legislators were motivated to pass anti-abortion statutes only to protect women, why did they not protect other patients by banning other potentially dangerous fatal elective surgeries?
Coincidentally or not, during this period of pro-life legislative activity Congress passed and 28 states ratified the 14th Amendment, prohibiting any state from depriving “any person of life, liberty, or property without the due process of law.”
By 1910, every state except Kentucky had passed an anti-abortion law (and Kentucky’s courts had declared abortion at any stage of gestation to be illegal).
By 1967, not much had changed. In 49 states, abortion was a felony; in New Jersey, it was a high misdemeanor. Furthermore, 29 states banned abortion advertising, and many outlawed the manufacture or distribution of abortifacients. In 1967, though, state abortion laws began to change, but only after years of organized campaigns by pro-abortion forces.
The American Law Institute (ALI) proposed, in its 1959 model criminal code for all the states, a “reform” abortion law. The model bill, approved by ALI in 1962, declared that abortion should be permitted for the physical or mental health of the mother, for fetal abnormality, and for rape or incest.
While leaders of the American legal community were promoting radical changes in state abortion law, a 1962 case in Arizona generated sympathetic press coverage of the notion of “justifiable abortion.”
Mrs. Sherri Finkbine, a married mother, made public her intention to abort her fifth child. She had taken some tranquilizers/sleeping pills her husband had brought home from a trip to England. The pills turned out to be Thalidomide, a drug that had become associated with birth defects. Fearful of giving birth to a handicapped child, Mrs Finkbine traveled to Sweden, where she had her baby aborted.
In June 1967, the American Medical Association voted to change that body’s long-standing opposition to abortion. With a new resolution, the AMA now condoned abortion for the life or health of the mother, for a baby’s ‘incapacitating’ physical deformity or mental deficiency, or for cases of rape or incest.
That same year, Colorado, North Carolina, and California became the first states to adopt versions of the ALI “reform” abortion law. By 1970, though, four states - New York, Alaska, Hawaii and Washington - passed laws that basically allowed abortion on demand. Of those four, New York’s was the only law without a residency requirement and the state quickly became the nation’s abortion capital.
The pro-abortion onslaught was beginning to face opposition, though, as pro-life forces organized. In 1972, the New York legislature voted to repeal the state’s liberal abortion law, but Governor Nelson Rockefeller vetoed the repeal. Ballot questions in Michigan and North Dakota in 1972 attempted to decriminalize abortion; the measures were defeated by majorities of 63% and 78%, respectively.
Just as pro-lifers were beginning to turn the tide however, the Supreme Court handed down Roe vs Wade in January 1973. With one judicial stroke, over 200 years of legal protection for the unborn was rendered null and void. For the first time in American history, abortion was the “law of the land”.
I’m for scienific accuracy. The start of a unique individual occurs only after all genetic material from the sperm is in complete participation with the genetic material in the egg. Until then, the individual, is not yet one.
It takes about 16 days for this to happen with a conceived human egg. Look up ‘gastrulation’.
As for human life, no one can point out a beginning, because the entire process does not have a non-living state. Sperms and eggs have life too.
If you find all this problematic, then you have issues.
Are you for or against abortion? Please answer the question.
Against. Look up my posting history.
You should take your two copper coins and invest in some books on human developmental biology. The child begins to act as an individual human being within seconds after sperm entering the egg beginning with an immediate thickening of the egg wall denying entry of antoher sperm.
Your idea that conception takes 16 to 18 days brings your abject ignorance of developmental biology into sharp relief.
The child begins to act as an individual human being within seconds after sperm entering the egg beginning with an immediate thickening of the egg wall denying entry of antoher sperm.
It's a triggering mechanism from the sperm cell's acrosomal cap that causes the egg's membrane to deny entry of other sperm. The father's DNA has had no role to play at this time, and the fusion is not yet an individual (the chromosomes haven't yet paired).
In mammals, gastrulation occurs after implantation, around day 16 after fertilization in human embryogenesis. As the outer cell mass invades the endometrium, the inner cell mass divides into two layers: the epiblast and hypoblast. The hypoblast spreads out and covers the blastocoel to form the yolk sac. The yolk sac is an extraembryonic tissue that produces blood cells similar to the structure that surrounds the yolk in birds. The epiblast further divides into two more layers. The amnion layer forms the fluid filled cavity to surround and protect the embryo during pregnancy. The embryonic epiblast undergoes gastrulation.
Gastrulation, which occurs around 16 days after fertilisation, is the point in development when the implanted blastocyst develops three germ layers, the endoderm, the ectoderm and the mesoderm. It is at this point that the genetic code of the father becomes fully involved in the development of the embryo. Until this point in development, twinning is possible. Additionally, interspecies hybrids survive only until gastrulation, and have no chance of development afterward.
And exactly why do you believe that gastrulation marks anything beyond another stage of development. You clearly don’t understand the topic and are grasping at wiki straws. Here are some references from medical school textbooks used to teach the subjects of embryology, fetology, developmental biology, and OB/Gyn and highly respected, peer reviewed medical journals. They are quite explicit with regard to when an individual human being’s life begins.
“Often,this morula is inaccurately referred to as a fertilized egg because the blastomeres remain inside the female parents oocyte outer cell membrane. That is an incorrect characterization, because the 23 -chromosome oocyte no longer exists; all the cells within the morula have the unique genome46 chromosomes and a complement of mitochondrial DNA of the newly conceived individual life.” Moore and Persaud, The Developing Human, 6th ed., (p. 43)
“the proposition that an unborn child is a human being from conception is supported by standard textbooks on embryology or human biology”T.W. SADLER, LANGMANS MEDICAL EMBRYOLOGY (John N. Gardner ed., 6th ed.
“Fertilization is an important landmark because, under ordinary circumstances, a new, genetically distinct human being is thereby formed... The zygote is a unicellular human being... Ronan R. O’Rahilly, Fabiola Muller, (New York: Wiley-Liss), 5, 55. EMBRYOLOGY & TERATOLOGY
“Every time a sperm cell and ovum unite a new human being is created which is alive and will continue to live unless its death is brought about by some specific condition.”E.L. Potter and J.M. Craig, PATHOLOGY OF THE FETUS AND THE INFANT, 3d ed. (Chicago: Year Book Medical Publishers, vii.
“Physicians, biologists, and other scientists agree that conception marks the beginning of the life of a human beinga 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.” John C. Fletcher, Mark I. Evans, “Maternal Bonding in Early Fetal Ultrasound Examinations,” New England Journal of Medicine, February 17, 1983.
Now do feel free to provide some equally credible sources that state explicitly that the offspring of two human beings is EVER anything other than a human being.
Does the genetic makeup of the fertilized egg alter at any stage past the immediate point of entry of the sperm, into the egg? Is the genetic arrangement of the fused gametes final, before gastrulation?
Without a unique DNA, you don’t have an individual.
As I said, do feel free to provide some equally credible material that states explicitly that the offspring of two human beings is ever anything but a human being.
Railing against credible material with nothing more than your opinion is the act of a flat earther. If it is true that unborns in the early stage of development are something other than living human beings, you should have no problem at all providing at least as much credible reference material to me as I have provided to you.
Good luck. You may as well be trying to prove that the moon is made of cheese.
By the way, a zygote has unique DNA.
Not to mention that I don't know why you're asking the above, you did not answer my previous query, which, in itself, was asked about several days ago.
Your previous post has no mention of the processes leading up to gastrulation, nor does it mention anything about how long it takes for the father's genetic material to combine fully with the mother's. I stated that (from the WiKi article, which has a citation link, which also happens to be where you sourced the material for your earlier post) the genetic material from the sperm hasn't completed combination with that from the mother until the 16th day. This is an important distinction because only after the genetics of the offspring is determined, will it be capable of being considered an individual.
I should have clarified this in my previous post, that your earlier post didn't answer what was argued a couple of days ago, but this should suffice.
By the way, a zygote has unique DNA.
This was not the argument. The argument was revolving around when the father's genes have completed involving themselves with those of the mother's. Just the entry of the sperm into the egg, isn't the instant when an individual is genetically determined.
Citation: Moore, K. L. & T. V. M. Persaud (2003). The Developing Human: Clinically Oriented Embryology. W. B. Saunders Company. ISBN 0-7216-6974-3.
If you have access to a journal, perhaps you can look it up. I don't, for now.
At the point where the surface of the egg changes and no other sperm can enter, yes, it is the instant when an individual is genetically determined. It similar to if someone pushed you off of a very tall building. At the point where you can no longer be pulled back or hang on and start falling unstoppably to the ground is the point at which your death is determined, even if you don't actually die until you hit the pavement below. It's also why pushing you off of the building would be considered murder, even though the push and the fall didn't kill you, the sudden deceleration at the end did.
Of course this whole objection is entirely irrelevant because the distinction you are looking for matters only if someone were to hover above an egg as it was being fertilized and were to destroy it between the point the first sperm entering the egg and the comination of the genetic material from sperm and egg. This will never happen in practice and is thus irrelevant, just as the determining the point at which you'd actually die if you fell to the ground from a high height between the moment when the first part of your body hit the ground and the point where your remains where liquified and distributed across a broad area is irrelevant because nobody is going to every stop that process in the middle in a way where it will matter. This is the classic post-modern strategy to dismissing anything. Insist on looking only at the trees and then claim the forest doesn't exist.
Tell that to thousands of identical twins. There are also plenty of science fiction thought experiments to the contrary (e.g., the Star Trek episodes where a person is split into two people by a transporter accident).