Quick Scientific References: Human Cloning, Human Embryonic Stem Cell Research

Dianne N. Irving
Aug. 31, 2004
Reproduced with Permission

Quick scientific references documenting -- with direct quotes from current human embryology and human molecular textbooks in concert with the international nomenclature -- that (1) no such thing as a "pre-embryo" or any similar "pre-embryo substitute"; (2) the immediate product of sexual (fertilization) reproduction is a new living single-cell human being, human organism, human individual, human embryo; (3) the immediate product of asexual reproduction (cloning, genetic engineering), is a new living single-cell human being, etc.:


1. The claim that there is no human being immediately present at fertilization or cloning is scientifically false,that the only thing there is a "cell" or "ball of cells" rather than a human organism, is what is referred to as a "pre-embryo substitute", i.e., just like the so-called "pre-embryo" it deserves "respect" but has a "reduced moral status" (and therefore can be used and destroyed in research). But the fake term "pre-embryo" has been formally scientifically rejected by the international Nomina Embryologica Committee, and therefore any similar attempt to falsify the science with a similar "pre-embryo substitute" is likewise scientifically false. Here's an example of the formal rejection of the term "pre-embryo" from Dr. Ronan O'Rahilly's classic human embryology textbook. O'Rahilly has sat on the international nomenclature committee for decades, and was one of the original founders of The Carnegie Stages of Early Human Embryological Development (internationally required to be used professionally in all textbooks written by human embryologists):

-- O'Rahilly and Muller, Human Embryology & Teratology (New York: Wiley-Liss, 2001): ... The term 'pre-embryo' is not used here for the following reasons: (1) it is ill-defined because it is said to end with the appearance of the primitive streak or to include neurulation; (2) it is inaccurate because purely embryonic cells can already be distinguished after a few days, as can also the embryonic (not pre-embryonic!) disc; (3) it is unjustified because the accepted meaning of the word embryo includes all of the first 8 weeks; (4) it is equivocal because it may convey the erroneous idea that a new human organism is formed at only some considerable time after fertilization; and (5) it was introduced in 1986 'largely for public policy reasons'(Biggers). ... Just as postnatal age begins at birth, prenatal age begins at fertilization." (p. 88)

2. Scientific References: The immediate product of sexual reproduction is a new living human organism, a human being, a human individual, a human embryo:

-- KEITH MOORE AND T.V.N. PERSAUD, The Developing Human: Clinically Oriented Embryology (6th ed. only) (Philadelphia: W.B. Saunders Company, 1998): Sutton and Boveri declared independently in 1902 that the behavior of chromosomes during germ cell formation and fertilization agreed with Mendel's principles of inheritance. In the same year, Garrod reported alcaptonuria as the first example of mendelian inheritance in human beings. Many consider Garrod to be the Father of Medical Genetics. It was soon realized that the zygote contains all the genetic information necessary for directing the development of a new human being. (p. 12) ... Human development is a continuous process that begins when an oocyte (ovum) from a female is fertilized by a sperm (or spermatozoon) from a male. (p. 2); ... but the embryo begins to develop as soon as the oocyte is fertilized. (p. 2); ... Zygote: this cell results from the union of an oocyte and a sperm. A zygote is the beginning of a new human being (i.e., an embryo). (p. 2); ... Human development begins at fertilization, the process during which a male gamete or sperm ... unites with a female gamete or oocyte ... to form a single cell called a zygote. This highly specialized, totipotent cell marks the beginning of each of us as a unique individual. (p. 18) ... The usual site of fertilization is the ampulla of the uterine tube [fallopian tube], its longest and widest part. If the oocyte is not fertilized here, it slowly passes along the tube to the uterus, where it degenerates and is resorbed. Although fertiization may occur in other parts of the tube, it does not occur in the uterus. ... Human development begins when a oocyte is fertilized. Fertilization ... begins with contact between a sperm and a oocute and ends with the intermingling of maternal and paternal chromosomes ... of the zygote, a unicellular embryo. (p. 34) ... The zygote is genetically unique because half of its chromosomes come from the mother and half from the father. The zygote contains a new combination of chromosomes that is different from that in the cells of either of the parents. This mechanism forms the basis of biparental inheritance and variation of the human species. Meiosis allows independent assortment of maternal and paternal chromosomes among the germ cells. ... The embryo's chromosomes sex is determined at fertilization by the kind of sperm (S or Y) that fertilizes the ovum; hence it is the father rather than the mother whose gamete determines the sex of the embryo. (p. 37)


-- BRUCE M. CARLSON, Human Embryology and Developmental Biology (St. Louis, MO: Mosby, 1994): Human pregnancy begins with the fusion of an egg and a sperm. (p. 3); ... finally, the fertilized egg, now properly called an embryo, must make its way into the uterus (p. 3); ... The sex of the future embryo is determined by the chromosomal complement of the spermatozoon ... Through the mingling of maternal and paternal chromosomes, the zygote is a genetically unique product of chromosomal reassortment .. (p. 31); ... "After the eighth week of pregnancy the period of organogenesis (embryonic period) is largely completed and the fetal period begins. (p. 407)


-- BRUCE M. CARLSON, Human Embryology & Developmental Biology (St. Louis, MO: Mosby, 1999): "Human pregnancy begins with the fusion of an egg and a sperm, but a great deal of preparation [recedes this event. First both male and female sex cells must pass through a long series of changes (gametogenesis) that convert them genetically and phenotypically into mature gametes, which are capable of participating in the process of fertilization. Next, the gametes must be released from the gonads and make their way to the upper part of the uterine tube, where fertilization normally takes place. ... Finally, the fertilized egg, now properly called an embryo, must make its way into the uterus ....". (p. 2); ... Fertilization age: dates the age of the embryo from the time of fertilization. (p. 23) ... In the female, sperm transport begins in the upper vagina and ends in the ampulla of the uterine tube [fallopian tube] where the spermatozoa make contact with the ovulated egg. (p. 27) ... After the eighth week of pregnancy the period of organogenesis (embryonic period) is largely completed, and the fetal period begins." (p. 447). ... The sex of the future embryo is determined by the chromosomal complement of the spermatozoon. (If the sperm contains 22 autosomes and an X chromosome, the embryo will be a genetic female, and if it contains 22 autosomes and a Y chromosome, the embryo will be a male.) ... Through the mingling of maternal and paternal chromosomes, the zygote is a genetically unique product of chromosomal reassortment, which is important for the viability of any species. (p. 32)


-- WILLIAM J. LARSEN, Human Embryology (New York: Churchill Livingstone, 1997): 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 [not the uterus]... resulting in the formation of a zygote containing a single diploid nucleus. Embryonic development is considered to begin at this point. (p. 1); ... "These pronuclei fuse with each other to produce the single, diploid, 2N nucleus of the fertilized zygote. This moment of zygote formation may be taken as the beginning or zero time point of embryonic development. (p. 17).


-- RONAN O'RAHILLY AND FABIOLA MULLER, Human Embryology & Teratology (New York: Wiley-Liss, 1994): Fertilization is an important landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed. (p. 5); ... Fertilization is the procession of events that begins when a spermatozoon makes contact with a secondary oocyte or its investments ... (p. 19); ... The zygote ... is a unicellular embryo. (p. 19); ... Thus the diploid number [in the zygote] is restored and the embryonic genome is formed. The embryo now exists as a genetic unity. (p. 20); ... ... The embryo enters the uterine cavity after half a week, when probably at least 8-12 cells are present. (p. 23); ... The embryonic period proper ... occupies the first 8 postovulatory weeks (i.e., timed from the last ovulation) ... The fetal period extends from 8 weeks to birth. (p. 55); ...


*** -- RONAN O'RAHILLY AND FABIOLA MULLER, Human Embryology & Teratology (3rd ed.)(New York: Wiley-Liss, 2001): Although life is a continuous process, fertilization ... is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is formed when the chromosomes of the male and female pronuclei blend in the oocyte. This remains true even though the embryonic genome is not actually activated until 2-8 cells are present at about 2-3 days. ... During the embryonic period proper, milestones include fertilization, activation of embryonic from extra-embryonic cells, implantation, and the appearance of the primitive streak and bilateral symmetry. ... Fertilization is the procession of events that begins when a spermatozoon makes contact with a secondary oocyte or its investments, and ends with the intermingling of maternal and paternal chromosomes at metaphase of the first mitotic division of the zygote. ... Fertilization takes place normally in the ampulla (lateral end) of the uterine tube. (p. 31); ... [Events or phases of fertilization]: ... #12. Two pronuclei, which migrate to a central position in the ootid. #13. Coalescence of homologous chromosomes, resulting in a one-cell embryo. The two pronuclei do not fuse but their nuclear envelopes break down and form vesicles. The two groups of homologous chromosomes then move together and become arranged on the first cleavage spindle. [[[ i.e., the embryo begins before syngamy.]]] #14. The beginning of the first mitotic division of the zygote. The zygote is characteristic of the last phase of fertilization and is identified by the first cleavage spindle. It is a unicellular embryo and is a highly specialized cell. The combination of 23 chromosomes present in each pronucleus results in 46 chromosomes in the zygote. Thus the diploid number is restored and the embryonic genome is formed. The embryo now exists as a genetic unity. Items 12-14 in the list above have traditionally been regarded as constituting developmental stage 1. (p. 33); ... Prenatal life is conveniently divided into two phases: the embryonic and the fetal. ... [I]t is now accepted that the word embryo, as currently used in human embryology, means 'an unborn human in the first 8 weeks' from fertilization. Embryonic life begins with the formation of a new embryonic genome (slightly prior to its activation). (p. 87)


-- Geoffrey Sher, Virginia Marriage Davis, Jean Stoess, In Vitro Fertilization: The A.R.T. of Making Babies (New York: Facts On File, 1998): The moment a sperm penetrates the egg's zona pellucida, a reaction in the egg fuses the zona and the perivitelline membrane into an impermeable shield that prevents other sperm from entering. ... Propelled by contractions of the fallopian tube, the dividing embryo begins its three- or four-day journey back to the uterus and continues to divide after it reaches the uterus. (The fertilization process occurs near the middle of the fallopian tube -- not in the uterus.) (p. 18)

3. Scientific References: The immediate product of asexual human reproduction (e.g., cloning) is a new living human being, etc.:

TOM STRACHAN and ANDREW P. READ, Human Molecular Genetics 2 (New York: John Wiley & Sons, Inc, 1999): A form of animal cloning can also occur as a result of artificial manipulation to bring about a type of asexual reproduction. The genetic manipulation in this case uses nuclear transfer technology: a nucleus is removed from a donor cell then transplanted into an oocyte whose own nucleus has previously been removed. ... Nuclear transfer technology was first employed in embryo cloning, in which the donor cell is derived from an early embryo, and has been long established in the case of amphibia. ... Wilmut et al (1997) reported successful cloning of an adult sheep. For the first time, an adult nucleus had been reprogrammed to become totipotent once more, just like the genetic material in the fertilized oocyte from which the donor cell had ultimately developed.... Successful cloning of adult animals has forced us to accept that genome modifications once considered irreversible can be reversed and that the genomes of adult cells can be reprogrammed by factors in the oocyte to make them totipotent once again. (pp. 508-509)

Ian Wilmut: "The majority of reconstructed embryos were cultured in ligated oviducts of sheep... Most embryos that developed to morula or blastocyst after 6 days of culture were transferred to recipients and allowed to develop to term," etc. [I. Wilmut et al., "Viable offspring derived from fetal and adult mammalian cells," 385 Nature 810-813 (Feb. 27, 1997)], and also, "One potential use for this technique would be to take cells -- skin cells, for example -- from a human patient who had a genetic disease... You take these and get them back to the beginning of their life by nuclear transfer into an oocyte to produce a new embryo. From that new embryo, you would be able to obtain relatively simple, undifferentiated cells, which would retain the ability to colonize the tissues of the patient." - Ian Wilmut, in 7 Cambridge Quarterly of Healthcare Ethics 138 (Spring 1988).


On being asked in an interview: "Do you think that society should allow cloning of human embryos because of the great promise of medical benefit?"]: "Yes. Cloning at the embryo stage -- to achieve cell dedifferentiation -- could provide benefits that are wide ranging..." - Keith Campbell, head of embryology at PPL Therapeutics and co-author of Dr. Wilmut's landmark paper, in 7 Cambridge Quarterly of Healthcare Ethics 139 (Spring 1988).


Lee M. Silver, professor of molecular biology and evolutionary biology at Princeton University, "Yet there is nothing synthetic about the cells used in cloning... The newly created embryo can only develop inside the womb of a woman in the same way that all embryos and fetuses develop. Cloned children will be full-fledged human beings, indistinguishable in biological terms from all other members of the species. Thus, the notion of a soulless clone has no basis in reality.", in Remaking Eden: Cloning and Beyond in a Brave New World (Avon Books 1997), p. 107.


"This experiment [producing Dolly] demonstrated that, when appropriately manipulated and placed in the correct environment, the genetic material of somatic cells can regain its full potential to direct embryonic, fetal, and subsequent development." - National Institutes of Health, Background Paper: Cloning: Present uses and Promises, Jan. 29, 1998, p. 3.


"The Commission began its discussions fully recognizing that any effort in humans to transfer a somatic cell nucleus into an enucleated egg involves the creation of an embryo, with the apparent potential to be implanted in utero and developed to term." - Cloning Human Beings: Report and Recommendations of the National Bioethics Advisory Commission (Rockville, MD: June 1997), p. 3.


[Expressing disbelief that some deny that human cloning produces an embryo]: "If it's not an embryo, what is it?" - Jonathan Van Blerkom, human embryologist at University of Colorado, in American Medical News, Feb. 23, 1998, p. 32 (Dr. Van Blerkom said researchers' efforts to avoid the word "embryo" in this context are "self-serving.")

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