"5,337 biologists (96%) affirmed that a human’s life begins at fertilization...The majority of the sample identified as liberal (89%), pro-choice (85%) and non-religious (63%). In the case of Americans who expressed party preference, the majority identified as Democrats (92%)....most Americans believe that the question of “when life begins” is an important aspect of the U.S. abortion debate (82%); that most believe Americans deserve to know when a human’s life begins in order to give informed consent to abortion procedures (76%); and that most Americans believe a human’s life is worthy of legal protection once it begins (93%). Respondents also were asked: “Which group is most qualified to answer the question, ‘When does a human’s life begin?’” They were presented with several options—biologists, philosophers, religious leaders, Supreme Court Justices and voters. Eighty percent selected biologists, and the majority explained that they chose biologists because they view them as objective experts in the study of life."
https://quillette.com/2019/10/16/i-asked-thousands-of-biologists-when-life-begins-the-answer-wasnt-popular/
"We talk of human development not because a jumble of cells, which is perhaps initially atypical, gradually turns more and more into a human, but rather because the human being develops from a uniquely human cell. There is no state in human development prior to which one could claim that a being exists with not-yet-human individuality. On the basis of anatomical studies, we know today that no developmental phase exists that constitutes a transition from the not-yet-human to the human."
"In short, a fertilized egg (conceptus) is already a human being." -Erich Blechschmidt, Brian Freeman, The Ontogenetic Basis of Human Anatomy: The Biodynamic Approach to Development from Conception to Adulthood, North Atlantic Books, June 2004. pp 7,8
"We talk of human development not because a jumble of cells, which is perhaps initially atypical, gradually turns more and more into a human, but rather because the human being develops from a uniquely human cell. There is no state in human development prior to which one could claim that a being exists with not-yet-human individuality. On the basis of anatomical studies, we know today that no developmental phase exists that constitutes a transition from the not-yet-human to the human."
"In short, a fertilized egg (conceptus) is already a human being." -Erich Blechschmidt, Brian Freeman, The Ontogenetic Basis of Human Anatomy: The Biodynamic Approach to Development from Conception to Adulthood, North Atlantic Books, June 2004. pp 7,8
“Traditional ways of classifying catalog animals according to their adult structure. But, as J. T. Bonner (1965) pointed out, this is a very artificial method, because what we consider an individual is usually just a brief slice of its life cycle. When we consider a dog, for instance, we usually picture an adult. But the dog is a “dog” from the moment of fertilization of a dog egg by a dog sperm. It remains a dog even as a senescent dying hound. Therefore, the dog is actually the entire life cycle of the animal, from fertilization through death.” -Scott Gilbert, Developmental Biology, 6th Edition
“All of us were once human embryos, so the study of human embryology is the study of our own prenatal origins and experiences.” (p. 2) “Fertilization, the uniting of egg and sperm, takes place in the oviduct. After the oocyte finishes meiosis, the paternal and maternal chromosomes come together, resulting in the formation of a zygote containing a single diploid nucleus. Embryonic development is considered to begin at this point.”
Schoenwolf, G. C. Larsen’s Human Embryology, 5th edition. Philadelphia, PA: Elsevier, Saunders, 2015. p. 2, 14.(p.14)
“The life cycle of mammals begins when a sperm enters an egg.” Okada et al., A role for the elongator complex in zygotic paternal genome demethylation, NATURE 463:554 (Jan. 28, 2010)
“All of us were once human embryos, so the study of human embryology is the study of our own prenatal origins and experiences.” (p. 2) “Fertilization, the uniting of egg and sperm, takes place in the oviduct. After the oocyte finishes meiosis, the paternal and maternal chromosomes come together, resulting in the formation of a zygote containing a single diploid nucleus. Embryonic development is considered to begin at this point.”
Schoenwolf, G. C. Larsen’s Human Embryology, 5th edition. Philadelphia, PA: Elsevier, Saunders, 2015. p. 2, 14.(p.14)
“The life cycle of mammals begins when a sperm enters an egg.” Okada et al., A role for the elongator complex in zygotic paternal genome demethylation, NATURE 463:554 (Jan. 28, 2010)
“Fertilization is the process by which male and female haploid gametes (sperm and egg) unite to produce a genetically distinct individual.”
-Signorelli et al., Kinases, phosphatases and proteases during sperm capacitation, CELL TISSUE RES. 349(3):765 (Mar. 20, 2012)
“The oviduct or Fallopian tube is the anatomical region where every new life begins in mammalian species. After a long journey, the spermatozoa meet the oocyte in the specific site of the oviduct named ampulla, and fertilization takes place.”
-Coy et al., Roles of the oviduct in mammalian fertilization, REPRODUCTION 144 (6): 649 (Oct. 1, 2012)
"Fertilization is the epic story of a single sperm facing incredible odds to unite with an egg, and form a new human life. It is the story of all of us." "The two sets of chromosomes join together, completing the process of fertilization. At this moment, a unique genetic code arises, instantly determining gender, hair color, eye color, and hundreds of other characteristics. This new single cell, the zygote, is the beginning of a new human being."
https://www.youtube.com/watch?v=BFrVmDgh4v49 (Fertilization (Conception) by Nucleus Medical Media)
"The two cells gradually and gracefully become one. This is the moment of conception, when an individual's unique set of DNA is created, a human signature that never existed before and will never be repeated."
https://www.youtube.com/watch?v=33R2zTGK1eM (In the Womb by National Geographic)
"Biologically speaking, fertilization (or conception) is the beginning of human development...Fertilization begins with the spermatozoon contacting the cells surrounding the oocyte and ends with the mixing of the 23 male and 23 female chromosomes. The result is a single-cell embryo called a zygote, meaning "yoked or joined together," and it is the first cell of the human body. The zygote, like the oocyte, is encased by its protective covering, the zona pellucida, and contains 46 unique chromosomes with the entire genetic blueprint of a new individual."
http://www.ehd.org/dev_article_unit1.php#fertilization (Prenatal Form and Function – The Making of an Earth Suit by the Endowment of Human Development)
*"Biologically speaking, human development begins at fertilization...The result is a single-cell embryo called a zygote, meaning "yoked or joined together""The zygote's 46 chromosomes represent the unique first edition of a new individual's complete genetic blueprint. This master plan resides in tightly coiled molecules called DNA. They contain the instructions for the development of the entire body. DNA molecules resemble a twisted ladder known as a double helix."
"From the completion of 8 weeks until the end of pregnancy, the developing human is called a fetus, which means "unborn offspring."
http://www.ehd.org/pdf/BPD%204-26-2006%20English.pdf (The Biology of Human Development by National Geographic and The Endowment of Human Development)
"Fertilization occurs when the nuclei of a sperm and an egg fuse to form a diploid cell, known as zygote. The successful fusion of gametes forms a new organism."
http://en.wikipedia.org/wiki/Human_fertilization (even wikipedia acknowledges a zygote is a new organism)
"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."
"Fertilization occurs when the nuclei of a sperm and an egg fuse to form a diploid cell, known as zygote. The successful fusion of gametes forms a new organism."
http://en.wikipedia.org/wiki/Human_fertilization (even wikipedia acknowledges a zygote is a new organism)
"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."
-"Human Embryology & Teratology, 3rd Edition, New York: Wiley-Liss, 2001. p. 8." by Ronan R. O'Rahilly and Fabiola Müller
“Although human life is a continuous process, fertilization is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed. … 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.”
-[O'Rahilly, Ronan and Muller, Fabiola. Human Embryology & Teratology. 2nd edition. New York: Wiley-Liss, 1996, pp. 8, 29. This textbook lists "pre-embryo" among "discarded and replaced terms" in modern embryology, describing it as "ill-defined and inaccurate" (p. 12}]
"Although human development is usually divided into prenatal (before birth) and postnatal (after birth) periods, development is a continuum that begins at fertilization (conception). Birth is a dramatic event during development, resulting in change in environment.
Development does not stop at birth; important developmental changes occur after birth-- development of teeth and female breasts, for example."
-[O'Rahilly, Ronan and Muller, Fabiola. Human Embryology & Teratology. 2nd edition. New York: Wiley-Liss, 1996, pp. 8, 29. This textbook lists "pre-embryo" among "discarded and replaced terms" in modern embryology, describing it as "ill-defined and inaccurate" (p. 12}]
"Although human development is usually divided into prenatal (before birth) and postnatal (after birth) periods, development is a continuum that begins at fertilization (conception). Birth is a dramatic event during development, resulting in change in environment.
Development does not stop at birth; important developmental changes occur after birth-- development of teeth and female breasts, for example."
-"Before We Are Born : Essentials of Embryology and Birth Defects,(5th Edition) (Philadelphia: W.B. Saunders Company, 1998) 36." by Keith L. Moore and T. V. N. Persaud
"Human life begins at fertilization, the process during which a male gamete or sperm (spermatozoo developmentn) unites with a female gamete or oocyte (ovum) to form a single cell called a zygote. This highly specialized, totipotent cell marked the beginning of each of us as a unique individual."
"A zygote is the beginning of a new human being (i.e., an embryo)."
"Human life begins at fertilization, the process during which a male gamete or sperm (spermatozoo developmentn) unites with a female gamete or oocyte (ovum) to form a single cell called a zygote. This highly specialized, totipotent cell marked the beginning of each of us as a unique individual."
"A zygote is the beginning of a new human being (i.e., an embryo)."
“Human development is a continuous process that begins when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male. Cell division, cell migration, programmed cell death, differentiation, growth, and cell rearrangement transform the fertilized oocyte, a highly specialized, totipotent cell – a zygote – into a multicellular human being. Although most developmental changes occur during the embryonic and fetal periods, important changes occur during later periods of development: infancy, childhood, adolescence, and early adulthood. Development does not stop at birth. Important changes, in addition to growth, occur after birth (e.g., development of teeth and female breasts). The brain triples in weight between birth and 16 years; most developmental changes are completed by the age of 25. Although it is customary to divide human development into prenatal (before birth) and postnatal (after birth) periods, birth is merely a dramatic event during development resulting in a change in environment.” (p. 2)
“Embryo. The developing human during its early stages of development. The embryonic period extends to the end of the eighth week (56 days), by which time the beginnings of all major structures are present.” (p. 3)
“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.” (p. 33)
-"The Developing Human: Clinically Oriented Embryology, 7th edition, Philadelphia, PA: Saunders, 2003, pp. 16, 2." by Keith L. Moore and T. V. N. Persaud
“Human development begins at fertilization when a sperm fuses with an oocyte to form a single cell, the zygote.”
“All major external and internal structures are established during the fourth to eighth weeks.”
“Upper limb buds are recognizable at day 26 or 27 as small swellings on the ventrolateral body walls.”
“Embryos in the sixth week show spontaneous movements, such as twitching of the trunk and developing limbs.”
“By the end of this week (8th week), the embryo has distinct human characteristics; however, the head is still disproportionately large, constituting almost half of the embryo.”
-The Developing Human 10th edition, by Keith L Moore, T.V.N. Persaud, and Mark Torchia, 205
-The Developing Human 10th edition, by Keith L Moore, T.V.N. Persaud, and Mark Torchia, 205
"The scientific answer is that the embryo is a human being from the time of fertilization because of its human chromosomal constitution. The zygote is the beginning of a developing human."
Keith L. Moore, T.V.N. Persaud, Mark G. Torchia, Before We Are Born: Essentials of Embryology, 8th edition. Philadelphia, PA: Saunders, 2013. p.327
"[The zygote], formed by the union of an oocyte and a sperm, is the beginning of a new human being."
-Keith L. Moore, Before We Are Born: Essentials of Embryology, 7th edition. Philadelphia, PA: Saunders, 2008. p. 2.
"Fertilization is the process whereby the sperm and egg--collectively called gametes--fuse together to begin the creation of a new individual whose genome is derived from both parents... Thus, the first function of fertilization is to transmit genes from parent to offspring" -Developmental Biology 10th edition by Scott F. Gilbert.
"Almost all higher animals start their lives from a single cell, the fertilized ovum (zygote)... The time of fertilization represents the starting point in the life history, or ontogeny, of the individual." -Carlson, Bruce M. Patten's Foundations of Embryology. 6th edition. New York: McGraw-Hill, 1996, p. 3
"The development of a human being begins with fertilization, a process by which two highly specialized cells, the spermatozoon from the male and the oocyte from the female, unite to give rise to a new organism, the zygote." -Langman, Jan. Medical Embryology. 3rd edition. Baltimore: Williams and Wilkins, 1975, p. 3
"It is the penetration of the ovum by a spermatozoan and resultant mingling of the nuclear material each brings to the union that constitutes the culmination of the process of fertilization and marks the initiation of the life of a new individual." -Human Embryology, 3rd ed. Bradley M. Patten, (New York: McGraw Hill, 1968), 43
“The zygote is human life….there is one fact that no one can deny; Human beings begin at conception."- Landrum B. Shettles, M.D., P.h.D.
“The zygote and early embryo are living human organisms.” Keith L. Moore & T.V.N. Persaud Before We Are Born – Essentials of Embryology and Birth Defects (W.B. Saunders Company, 1998. Fifth edition.) Page 500
"Fertilization is the process whereby the sperm and egg--collectively called gametes--fuse together to begin the creation of a new individual whose genome is derived from both parents... Thus, the first function of fertilization is to transmit genes from parent to offspring" -Developmental Biology 10th edition by Scott F. Gilbert.
"Almost all higher animals start their lives from a single cell, the fertilized ovum (zygote)... The time of fertilization represents the starting point in the life history, or ontogeny, of the individual." -Carlson, Bruce M. Patten's Foundations of Embryology. 6th edition. New York: McGraw-Hill, 1996, p. 3
"The development of a human being begins with fertilization, a process by which two highly specialized cells, the spermatozoon from the male and the oocyte from the female, unite to give rise to a new organism, the zygote." -Langman, Jan. Medical Embryology. 3rd edition. Baltimore: Williams and Wilkins, 1975, p. 3
"It is the penetration of the ovum by a spermatozoan and resultant mingling of the nuclear material each brings to the union that constitutes the culmination of the process of fertilization and marks the initiation of the life of a new individual." -Human Embryology, 3rd ed. Bradley M. Patten, (New York: McGraw Hill, 1968), 43
“The zygote is human life….there is one fact that no one can deny; Human beings begin at conception."- Landrum B. Shettles, M.D., P.h.D.
“The zygote and early embryo are living human organisms.” Keith L. Moore & T.V.N. Persaud Before We Are Born – Essentials of Embryology and Birth Defects (W.B. Saunders Company, 1998. Fifth edition.) Page 500
"Development begins with fertilization, the process by which the male gamete, the sperm, and the female gamete, the oocyte, unite to give rise to a zygote."
-T.W. Sadler, Langman's Medical Embryology, 10th edition. Philadelphia, PA: Lippincott Williams & Wilkins, 2006. p. 11.
"Human embryos begin development following the fusion of definitive male and female gametes during fertilization... This moment of zygote formation may be taken as the beginning or zero time point of embryonic development."
-William J. Larsen, Essentials of Human Embryology. New York: Churchill Livingstone, 1998. pp. 1, 14.
"A Zygote (Created fertilization) is the beginning of a new human being. Human development begins at fertilization."
-Developing Human Clinical 6th edition
"An Embryo is an organism in the earliest stages of development."
-Harper Collins Illustrated medical dictionary
"It is an established fact that life, including human life, begins at the moment of conception…"- r. Hymie Gordon, professor of medical genetics and physician at the Mayo Clinic
"It is an established fact that life, including human life, begins at the moment of conception…"- r. Hymie Gordon, professor of medical genetics and physician at the Mayo Clinic
"It is the penetration of the ovum by a spermatozoan and resultant mingling of the nuclear material each brings to the union that constitutes the culmination of the process of fertilization and marks the initiation of the life of a new individual."
-Clark Edward Corliss, Patten's Human Embryology: Elements of Clinical Development. New York: McGraw Hill, 1976. p. 30.
"The term conception refers to the union of the male and female pronuclear elements of procreation from which a new living being develops. It is synonymous with the terms fecundation, impregnation, and fertilization."
"The zygote thus formed represents the beginning of a new life."
"The term conception refers to the union of the male and female pronuclear elements of procreation from which a new living being develops. It is synonymous with the terms fecundation, impregnation, and fertilization."
"The zygote thus formed represents the beginning of a new life."
-J.P. Greenhill and E.A. Friedman, Biological Principles and Modern Practice of Obstetrics. Philadelphia: W.B. Saunders, 1974. pp. 17, 23.
"Every time a sperm cell and ovum unite a new being is created which is alive and will continue to live unless its death is brought about by some specific condition."
"Every time a sperm cell and ovum unite a new 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, 3rd edition. Chicago: Year Book Medical Publishers, 1975. p. vii.
“Embryo: The developing individual between the union of the germ cells and the completion of the organs which characterize its body when it becomes a separate organism…. At the moment the sperm cell of the human male meets the ovum of the female and the union results in a fertilized ovum (zygote), a new life has begun…. The term embryo covers the several stages of early development from conception to the ninth or tenth week of life.”
[Considine, Douglas (ed.). Van Nostrand's Scientific Encyclopedia. 5th edition. New York: Van Nostrand Reinhold Company, 1976, p. 943]
Dr. Jerome Lejeune of Paris, France was a medical doctor, a Doctor of Science and a professor of Fundamental Genetics for over twenty years. Dr. Lejeune discovered the genetic cause of Down Syndrome, receiving the Kennedy Prize for the discovery and, in addition, received the Memorial Allen Award Medal, the world's highest award for work in the field of Genetics. He is often called the "Father of Modern Genetics". The following are some notable statements by him:
"After fertilization has taken place a new human being has come into existence. This is no longer a matter of taste or opinion. Each individual has a very neat beginning, at conception."
- 1989 court testimony in Tennessee, cf. also Louisiana Legislature's House Committee on the Administration of Criminal Justice on June 7, 1990
[Considine, Douglas (ed.). Van Nostrand's Scientific Encyclopedia. 5th edition. New York: Van Nostrand Reinhold Company, 1976, p. 943]
Dr. Jerome Lejeune of Paris, France was a medical doctor, a Doctor of Science and a professor of Fundamental Genetics for over twenty years. Dr. Lejeune discovered the genetic cause of Down Syndrome, receiving the Kennedy Prize for the discovery and, in addition, received the Memorial Allen Award Medal, the world's highest award for work in the field of Genetics. He is often called the "Father of Modern Genetics". The following are some notable statements by him:
"After fertilization has taken place a new human being has come into existence. This is no longer a matter of taste or opinion. Each individual has a very neat beginning, at conception."
- 1989 court testimony in Tennessee, cf. also Louisiana Legislature's House Committee on the Administration of Criminal Justice on June 7, 1990
1981 Us Senate sub committee
Dr. Michelin Mathews Roth
"It is incorrect to say that biological data can not be decisive. It is scientifically correct to say that an individual human life begins at conception."
*reached a conclusion after all their testimony that physicians and biologists agree that human life begins at conception.
"The human nature of the human being from conception to old age is not a metaphysical contention, it is plain experimental evidence."
- The Subcommittee on Separation of Powers, Report to Senate Judiciary Committee S-158, 97th
Congress, First Session, 1981
"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 official Senate report from Subcommittee on Separation of Powers to Senate Judiciary Committee S-158, Report, 97th Congress, 1st Session, 1981
Background on the Committee testifiers:
A group of internationally-known biologists and geneticists appeared to speak on behalf of the scientific community on the subject of when a human being begins. They all presented the same view and there was no opposing testimony. Among those testifying:
Dr. Micheline M. Mathews-Roth, Harvard medical School
Dr. Jerome Lejeune (“Father of Modern Genetics”)
Dr. McCarthy de Mere, medical doctor and law professor, University of Tennessee
Dr. Alfred Bongiovanni, Professor of Pediatrics and Obstetrics, University of Pennsylvania School of Medicine
Dr. Richard V. Jaynes
Dr. Landrum Shettles, sometimes called the "Father of In Vitro Fertilization"
Professor Eugene Diamond
Gordon, Hymie, M.D., F.R.C.P., Chairman of Medical Genetics, Mayo Clinic, Rochester
C. Christopher Hook, M.D. Oncologist, Mayo Clinic, Director of Ethics Education, Mayo Graduate School of Medicine
Dr. Michelin Mathews Roth
"It is incorrect to say that biological data can not be decisive. It is scientifically correct to say that an individual human life begins at conception."
*reached a conclusion after all their testimony that physicians and biologists agree that human life begins at conception.
"The human nature of the human being from conception to old age is not a metaphysical contention, it is plain experimental evidence."
- The Subcommittee on Separation of Powers, Report to Senate Judiciary Committee S-158, 97th
Congress, First Session, 1981
"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 official Senate report from Subcommittee on Separation of Powers to Senate Judiciary Committee S-158, Report, 97th Congress, 1st Session, 1981
Background on the Committee testifiers:
A group of internationally-known biologists and geneticists appeared to speak on behalf of the scientific community on the subject of when a human being begins. They all presented the same view and there was no opposing testimony. Among those testifying:
Dr. Micheline M. Mathews-Roth, Harvard medical School
Dr. Jerome Lejeune (“Father of Modern Genetics”)
Dr. McCarthy de Mere, medical doctor and law professor, University of Tennessee
Dr. Alfred Bongiovanni, Professor of Pediatrics and Obstetrics, University of Pennsylvania School of Medicine
Dr. Richard V. Jaynes
Dr. Landrum Shettles, sometimes called the "Father of In Vitro Fertilization"
Professor Eugene Diamond
Gordon, Hymie, M.D., F.R.C.P., Chairman of Medical Genetics, Mayo Clinic, Rochester
C. Christopher Hook, M.D. Oncologist, Mayo Clinic, Director of Ethics Education, Mayo Graduate School of Medicine
“Embryo: An organism in the earliest stage of development; in a man, from the time of conception to the end of the second month in the uterus.”
(Dox, Ida G. et al. The Harper Collins Illustrated Medical Dictionary. (New York: Harper Perennial, 1993) p. 146.
“…Every human embryologist in the world knows that the life of the new individual human being begins at fertilization. It is not belief. It is scientific fact.”
Ward Kischer, human embryologist, University of Arizona
“You Can Stop Injustice” Human Life Alliance Supplement, 2010
“The fusion of sperm and egg membranes initiates the life of a sexually reproducing organism.”
-Marsden et al., Model systems for membrane fusion, CHEM. SOC. REV. 40(3):1572 (Mar. 2011)
“In that fraction of a second when the chromosomes form pairs [at conception], the sex of the new child will be determined, hereditary characteristics received from each parent will be set, and a new life will have begun.”
-Kaluger, G., and Kaluger, M., Human Development: The Span of Life, page 28-29, The C.V. Mosby Co., St. Louis, 1974.
“It should always be remembered that many organs are still not completely developed by full-term and birth should be regarded only as an incident in the whole developmental process.”
-F Beck Human Embryology, Blackwell Scientific Publications, 1985 page vi
“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” (p. 1)
-Human Embryology, William J Larsen, 3rd Edition, 2001
-Marcello et al., Fertilization, ADV. EXP. BIOL. 757:321 (2013)
The government’s own definition attests to the fact that life begins at fertilization. According to the National Institutes of Health, “fertilization” is the process of union of two gametes (i.e., ovum and sperm) “whereby the somatic chromosome number is restored and the development of a new individual is initiated.”
-National Institutes of Health, Medline Plus Merriam-Webster Medical Dictionary (2013), http://c.merriam-webster.com/medlineplus/fertilization
“Your baby starts out as a fertilized egg… For the first six weeks, the baby is called an embryo.”
-Prenatal Care, US Department Of Health And Human Services, Maternal and Child Health Division, 1990
"Thus a new cell is formed from the union of a male and a female gamete. [sperm and egg cells] The cell, referred to as the zygote, contains a new combination of genetic material, resulting in an individual different from either parent and from anyone else in the world.”
-Sally B Olds, et al., Obstetric Nursing (Menlo Park, California: Addison – Wesley publishing, 1980) P 136
"[All] organisms, however large and complex they might be as full grown, begin life as a single cell. This is true for the human being, for instance, who begins life as a fertilized ovum.”
-Dr. Morris Krieger “The Human Reproductive System” p 88 (1969) Sterling Pub. Co
“The first cell of a new and unique human life begins existence at the moment of conception (fertilization) when one living sperm from the father joins with one living ovum from the mother. It is in this manner that human life passes from one generation to another. Given the appropriate environment and genetic composition, the single cell subsequently gives rise to trillions of specialized and integrated cells that compose the structures and functions of each individual human body. Every human being alive today and, as far as is known scientifically, every human being that ever existed, began his or her unique existence in this manner, i.e., as one cell. If this first cell or any subsequent configuration of cells perishes, the individual dies, ceasing to exist in matter as a living being. There are no known exceptions to this rule in the field of human biology.”
-James Bopp, ed., Human Life and Health Care Ethics, vol. 2 (Frederick, MD: University Publications of America, 1985)
"In fusing together, the male and female gametes produce a fertilized single cell, the zygote, which is the start of a new individual.”
-Rand McNally, Atlas of the Body (New York: Rand McNally, 1980) 139, 144
“… Conception confers life and makes you one of a kind. Unless you have an identical twin, there is virtually no chance, in the natural course of things, that there will be “another you” – not even if mankind were to persist for billions of years.”
-Shettles, Landrum, M.D., Rorvik, David, Rites of Life: The Scientific Evidence for Life Before Birth, page 36, Zondervan Publishing House, Grand Rapids, Michigan, 1983"Human life begins when the ovum is fertilized and the new combined cell mass begins to divide."
-From Newsweek November 12, 1973:Dr. Jasper Williams, Former President of the National Medical Association (p 74)
“The formation, maturation and meeting of a male and female sex cell are all preliminary to their actual union into a combined cell, or zygote, which definitely marks the beginning of a new individual. The penetration of the ovum by the spermatozoon, and the coming together and pooling of their respective nuclei, constitutes the process of fertilization.”
-Leslie Brainerd Arey, “Developmental Anatomy” seventh edition space (Philadelphia: Saunders, 1974), 55
“The zygote therefore contains a new arrangement of genes on the chromosomes never before duplicated in any other individual. The offspring destined to develop from the fertilized ovum will have a genetic constitution different from anyone else in the world.”
-DeCoursey, R.M., The Human Organism, 4th edition McGraw Hill Inc., Toronto, 1974. page 584
“The science of the development of the individual before birth is called embryology. It is the story of miracles, describing the means by which a single microscopic cell is transformed into a complex human being. Genetically the zygote is complete. It represents a new single celled individual.”
-Thibodeau, G.A., and Anthony, C.P., Structure and Function of the Body, 8th edition, St. Louis: Times Mirror/Mosby College Publishers, St. Louis, 1988. pages 409-419
“The development of a new human being begins when a male’s sperm pierces the cell membrane of a female’s ovum, or egg….The villi become the placenta, which will nourish the developing infant for the next eight and a half months.”
-Scarr, S., Weinberg, R.A., and Levine A., Understanding Development, Harcourt Brace Jovanovich, Inc., 1986. page 86
“Each human begins life as a combination of two cells, a female ovum and a much smaller male sperm. This tiny unit, no bigger than a period on this page, contains all the information needed to enable it to grow into the complex …structure of the human body. The mother has only to provide nutrition and protection.”
-Clark, J. ed., The Nervous System: Circuits of Communication in the Human Body, Torstar Books Inc., Toronto, 1985, page 99
“A zygote (a single fertilized egg cell) represents the onset of pregnancy and the genesis of new life.”
-Turner, J.S., and Helms, D.B., Lifespan Developmental, 2nd ed., CBS College Publishing (Holt, Rhinehart, Winston), 1983, page 53
“…but the whole story does not begin with delivery. The baby has existed for months before – at first signaling its presence only with small outer signs, later on as a somewhat foreign little being which has been growing and gradually affecting the lives of those close by…”
-Lennart Nilsson A Child is Born: Completely Revised Edition (Dell Publishing Co.: New York) 1986
"Embryo: 1. An organism developing inside a womb, egg, or seed. 2. A human baby in the first two months of growth in the womb.
Zygote: First cell of new living thing."
-The Usborne Internet-Linked Science Encyclopedia
"Every baby begins life within the tiny globe of the mother's egg... It is beautifully translucent and fragile and it encompasses the vital links in which life is carried from one generation to the next. Within this tiny sphere great events take place. When one of the father's sperm cells, like the ones gathered here around the egg, succeeds in penetrating the egg and becomes united with it, a new life can begin."
Geraldine Lux Flanagan, Beginning Life. New York: DK, 1996. p. 13.
Some of the world’s most prominent scientists and physicians testified to a U.S. Senate committee that human life begins at conception:
A United States Senate Judiciary Subcommittee invited experts to testify on the question of when life begins. All of the quotes from the following experts come directly from the official government record of their testimony.
Dr. Alfred M. Bongiovanni, professor of pediatrics and obstetrics at the University of Pennsylvania, stated:
“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. Jerome LeJeune, professor of genetics at the University of Descartes in Paris, was the discoverer of the chromosome pattern of Down syndrome. Dr. LeJeune testified to the Judiciary Subcommittee, “after fertilization has taken place a new human being has come into being.” He stated that this “is no longer a matter of taste or opinion,” and “not a metaphysical contention, it is plain experimental evidence.” He added, “Each individual has a very neat beginning, at conception.”
Professor Hymie Gordon, Mayo Clinic: “By all the criteria of modern molecular biology, life is present from the moment of conception.”
Professor Micheline Matthews-Roth, Harvard University Medical School: “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.... Our laws, one function of which is to help preserve the lives of our people, should be based on accurate scientific data.”
Dr. Watson A. Bowes, University of Colorado Medical School: “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.”
A prominent physician points out that at these Senate hearings, “Pro-abortionists, though invited to do so, failed to produce even a single expert witness who would specifically testify that life begins at any point other than conception or implantation. Only one witness said no one can tell when life begins.”
Many other prominent scientists and physicians have likewise affirmed with certainty that human life begins at conception:
Ashley Montague, a geneticist and professor at Harvard and Rutgers, is unsympathetic to the prolife cause. Nevertheless, he affirms unequivocally, “The basic fact is simple: life begins not at birth, but conception.”
Dr. Bernard Nathanson, internationally known obstetrician and gynecologist, was a cofounder of what is now the National Abortion Rights Action League (NARAL). He owned and operated what was at the time the largest abortion clinic in the western hemisphere. He was directly involved in over sixty thousand abortions.
Dr. Nathanson’s study of developments in the science of fetology and his use of ultrasound to observe the unborn child in the womb led him to the conclusion that he had made a horrible mistake. Resigning from his lucrative position, Nathanson wrote in the New England Journal of Medicine that he was deeply troubled by his “increasing certainty that I had in fact presided over 60,000 deaths.”
In his film, “The Silent Scream,” Nathanson later stated, “Modern technologies have convinced us that beyond question the unborn child is simply another human being, another member of the human community, indistinguishable in every way from any of us.” Dr. Nathanson wrote Aborting America to inform the public of the realities behind the abortion rights movement of which he had been a primary leader. At the time Dr. Nathanson was an atheist. His conclusions were not even remotely religious, but squarely based on the biological facts.
Dr. Landrum Shettles was for twenty-seven years attending obstetrician-gynecologist at Columbia-Presbyterian Medical Center in New York. Shettles was a pioneer in sperm biology, fertility, and sterility. He is internationally famous for being the discoverer of male- and female-producing sperm. His intrauterine photographs of preborn children appear in over fifty medical textbooks. Dr. Shettles states,
I oppose abortion. I do so, first, because I accept what is biologically manifest—that human life commences at the time of conception—and, second, because I believe it is wrong to take innocent human life under any circumstances. My position is scientific, pragmatic, and humanitarian.
The First International Symposium on Abortion came to the following conclusion:
The changes occurring between implantation, a six-week embryo, a six-month fetus, a one-week-old child, or a mature adult are merely stages of development and maturation. The majority of our group could find no point in time between the union of sperm and egg, or at least the blastocyst stage, and the birth of the infant at which point we could say that this was not a human life.
The Official Senate report on Senate Bill 158, the “Human Life Bill,” summarized the issue this way:
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 most authoritative scientific conclusion on when human life begins that has been made in recent years, was the conclusion from The First International Conference on Abortion, held in Washington DC, October 1967. Approximately 60 major scientific authorities from the field of medicine, ethics, law and social sciences participated as consultants in this symposium. Carefully chosen for their scientific knowledge and integrity, they presented a cross-section of race, religion, culture, and geographic backgrounds. After several days of “think tank” discussions, the medical group, made up of geneticists, biochemists, physicians, professors, research scientists, etc., came to a near unanimous conclusion (one dissension):
“The majority of our group could find no point in time between the union of sperm and egg, or at least the blastocyst stage, and the birth of the infant at which point we could say that this was not a human life [blastocyst stage occurs approximately one week after fertilization, and would account for twinning]”.… The changes occurring between implantation, the 6 week embryo, six-month fetus, a one week-old child, or mature adult are really stages of development and maturation.”
-“Five Ways to Kill an Unborn Child” from the Knights of Columbus
"Human development begins after the union of male and female gametes or germ cells during a process known as fertilization (conception).
"Fertilization is a sequence of events that begins with the contact of a sperm (spermatozoon) with a secondary oocyte (ovum) and ends with the fusion of their pronuclei (the haploid nuclei of the sperm and ovum) and the mingling of their chromosomes to form a new cell. This fertilized ovum, known as a zygote, is a large diploid cell that is the beginning, or primordium, of a human being."
[Moore, Keith L. Essentials of Human Embryology. Toronto: B.C. Decker Inc, 1988, p.2]
"Human development begins after the union of male and female gametes or germ cells during a process known as fertilization (conception).
"Fertilization is a sequence of events that begins with the contact of a sperm (spermatozoon) with a secondary oocyte (ovum) and ends with the fusion of their pronuclei (the haploid nuclei of the sperm and ovum) and the mingling of their chromosomes to form a new cell. This fertilized ovum, known as a zygote, is a large diploid cell that is the beginning, or primordium, of a human being."
[Moore, Keith L. Essentials of Human Embryology. Toronto: B.C. Decker Inc, 1988, p.2]
"Embryo: the developing organism from the time of fertilization until significant differentiation has occurred, when the organism becomes known as a fetus."
[Cloning Human Beings. Report and Recommendations of the National Bioethics Advisory Commission. Rockville, MD: GPO, 1997, Appendix-2.]
[Cloning Human Beings. Report and Recommendations of the National Bioethics Advisory Commission. Rockville, MD: GPO, 1997, Appendix-2.]
"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."
[Sadler, T.W. Langman's Medical Embryology. 7th edition. Baltimore: Williams & Wilkins 1995, p. 3]
[Sadler, T.W. Langman's Medical Embryology. 7th edition. Baltimore: Williams & Wilkins 1995, p. 3]
"The question came up of what is an embryo, when does an embryo exist, when does it occur. I think, as you know, that in development, life is a continuum.... But I think one of the useful definitions that has come out, especially from Germany, has been the stage at which these two nuclei [from sperm and egg] come together and the membranes between the two break down."
[Jonathan Van Blerkom of University of Colorado, expert witness on human embryology before the NIH Human Embryo Research Panel -- Panel Transcript, February 2, 1994, p. 63]
[Jonathan Van Blerkom of University of Colorado, expert witness on human embryology before the NIH Human Embryo Research Panel -- Panel Transcript, February 2, 1994, p. 63]
"Zygote. This cell, formed by the union of an ovum and a sperm (Gr. zyg tos, yoked together), represents the beginning of a human being. The common expression 'fertilized ovum' refers to the zygote."
[Moore, Keith L. and Persaud, T.V.N. Before We Are Born: Essentials of Embryology and Birth Defects. 4th edition. Philadelphia: W.B. Saunders Company, 1993, p. 1]
[Moore, Keith L. and Persaud, T.V.N. Before We Are Born: Essentials of Embryology and Birth Defects. 4th edition. Philadelphia: W.B. Saunders Company, 1993, p. 1]
"The chromosomes of the oocyte and sperm are...respectively enclosed within female and male pronuclei. 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."
[Larsen, William J. Human Embryology. 2nd edition. New York: Churchill Livingstone, 1997, p. 17]
"Development of the embryo begins at Stage 1 when a sperm fertilizes an oocyte and together they form a zygote."
[England, Marjorie A. Life Before Birth. 2nd ed. England: Mosby-Wolfe, 1996, p.31]
[England, Marjorie A. Life Before Birth. 2nd ed. England: Mosby-Wolfe, 1996, p.31]
"A human being at an embryonic age and that human being at an adult age are naturally the same. The biological differences are due only to the differences in maturity. Changes in methylation of cytosine demonstrate that the human being is fully programmed for human growth and development for his or her entire life at the one cell stage."
-Dr. David Fu-Chi Mark, a distinguished molecular biologist. Report of the South Dakota Task Force to Study Abortion, pp.21-25. quoted in United Families International Guide to Family Issues: Abortion (Gilbert, Arizona: United Families International, 2007) 24
“Every human embryologist, worldwide, states that the life of the new individual human being begins at fertilization (conception).… We exist as a continuum of human life, which begins at fertilization and continues until death.”
-Christine Watkins, editor The Ethics of Abortion (New York: Greenhaven press, 2005) 5
“Reproduction depends on the union of male and female gametes (reproductive, or germ, cells) each with a half set of chromosomes, to form a new individual with a full, unique set of chromosomes.”
-Human Physiology: From Cells to Systems 2nd Cd Ed,Sherwood, Kell & Ward, 2013, 2010, Nelson Education Ltd. 709
"ABSTRACT: The predominance of human biological research confirms that human life begins at conception—fertilization. At fertilization, the human being emerges as a whole, genetically distinct, individuated zygotic living human organism, a member of the species Homo sapiens, needing only the proper environment in order to grow and develop. The difference between the individual in its adult stage and in its zygotic stage is one of form, not nature. This statement focuses on the scientific evidence of when an individual human life begins. "
-American College of Pediatricians – March 2017
“[T]here is nothing in the entire phenomenon of the transmission of life that deserves more to be called an event, scientifically speaking, that does fertilization. It is the natural and scientific boundary at which a new and genetically unique human individual can be said to begin his existence. We conclude, therefore, that by objective and scientific criteria the individual human being is a person throughout his [or her] entire biological development from conception, which is synonymous with fertilization, to natural death… Any other conclusion would be arbitrary, unsupportable by scientific fact or rational argument, divorced from objective reality, and based on a particular ideology, philosophy or creed.”
-Direct report on S. 158 by Dr. Sean O’Reilly, Director of the Neurobiology Research Training Program at George Washington University, dated July 2, 1981
Quoted on page 28 – 29 of Randall J Hekman Justice for the Unborn (Ann Arbor, Michigan: Servant Books, 1984)
“The task force finds that the new recombinant DNA technologies indisputably prove that the unborn child is a whole human being from the moment of fertilization, that all abortions terminate the life of a living human being, and that the unborn child is a separate human patient under the care of modern medicine.”
“The task force cited scientific advances since 1973 as showing an embryo to be a “whole, separate, unique, living, human being” from the moment of conception. The advances in question include DNA fingerprinting, which shows a pattern of DNA that can identify an individual, and the polymerase chain reaction, which makes it possible to amplify and extract that information from a single cell. Techniques that show an embryo has a complete set of DNA “have proven that each human being is totally unique immediately at fertilization”, the panel’s report says. The task force also cited findings that control of growth and development are established by the embryo’s DNA after the third division of the fertilized egg: this stage is reached long before the embryo is implanted in the womb, which has previously been cited as signifying when personhood began.”
-“When does life begin?” New Scientist 3/18/2006, Vol. 189, Issue 2543
"Birth may be a grand occasion, says the Johns Hopkins University psychologist [Janet DiPietro], but “it is a trivial event in development. Nothing neurologically interesting happens.”
-Janet L. Hopson “Fetal Psychology” Psychology Today, Sep/Oct98, Vol. 31 Issue 5, p44, 6p, 4c.
“A composite, unified, sacrosanct, unanimity of thought as to when life begins can be determined by studying embryologic physiology. Scientifically acknowledged pronouncements should be more acceptable in determining the onset of human life than legal opinion.”
-Bernard J Ficarra, M.D. Abortion Analyzed (Laurel, MD: Health Educator Publications, Inc., 1989) 9
“the fertilized egg (zygote) is the beginning of a new diploid individual.”
Jones, R. E. Human Reproductive Biology, 4th edition. Waltham, MA. Elsevier, Academic Press, 2014, p. 169.
“Human development begins at fertilization when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male…Embryology is concerned with the origin and development of a human being from a zygote to birth.”
Keith L. Moore, Before We Are Born: Essentials of Embryology, 9th edition. Philadelphia, PA: Saunders, 2016. p. 1.
“The main results of fertilization are as follows: Restoration of the diploid number of chromosomes, half from the father half from the mother. Hence, the zygote contains a new combination of chromosomes different from both parents. Determination of the sex of the new individual. An X-carrying sperm produces a female (XX) embryo and a Y-carrying sperm produces a male (XY) embryo. Therefore, the chromosomal sex of the embryo is determined at fertilization.”
Sadler, T. W. Langman's Medical Embryology, 13th edition. Philadelphia, PA: Lippincott Williams & Wilkins, 2015. p. 42.
“Sexual reproduction occurs when female and male gametes (oocyte and spermatozoon, respectively) unite at fertilization.”
Dudek, R. W. Embryology, 4th edition. Philadelphia, PA. Lippincott Williams and Wilkins, 2008, p. 1.
“Fertilization is the sum of the cellular mechanisms that pass the genome from one generation to the next and initiate development of a new organism.”
Penetration, adhesion, and fusion in mammalian sperm-egg interaction. Primakoff P, Myles DG. Science. 2002. 296(5576):2183-5.
“Ca2+ signaling plays a crucial role in virtually all cellular processes, from the origin of new life at fertilization to the end of life when cells die.”
The cell cycle: a new entry in the field of Ca2+ signaling. Santella L, Ercolano E, Nusco GA. Cell Mol Life Sci. 2005. 62(21):2405-13.
“Representing the 60 trillion cells that build a human body, a sperm and an egg meet, recognize each other, and fuse to form a new generation of life.”
The immunoglobulin superfamily protein Izumo is required for sperm to fuse with eggs. Inoue N, Ikawa M, Isotani A, Okabe M. Nature. 2005. 434(7030):234-8.
“At fertilization, eggs unite with sperm to initiate developmental programs that give rise to development of the embryo. Defining the molecular mechanism of this fundamental process at the beginning of life has been a key question in cell and developmental biology.”
Signal transduction pathways leading to Ca2+ release in a vertebrate model system: lessons from Xenopus eggs. Sato K, Fukami Y, Stith BJ. Semin Cell Dev Biol. 2006. 17(2):285-92.
“Most readers of this review originated from a sperm-egg fusion event.”
Cell fusion during development. Oren-Suissa M, Podbilewicz B. Trends Cell Biol. 2007. 17(11):537-46.
“As representatives of the 60 trillion cells that make a human body, a sperm and an egg meet, recognize each other, and fuse to create a new generation.”
Sperm-egg fusion assay in mammals. Inoue N, Okabe M. Methods Mol Biol. 2008. 475:335-45.
“Sperm are remarkably complex cells with a singularly important mission: to deliver paternal DNA and its associated factors to the oocyte to start a new life.”
-Sperm chromatin: fertile grounds for proteomic discovery of clinical tools. Wu TF, Chu DS. Mol Cell Proteomics. 2008. 7(10):1876-86.
“A proper dialogue between spermatozoa and the egg is essential for conception of a new individual in sexually reproducing animals. Ca(2+) is crucial in orchestrating this unique event leading to a new life.”
Calcium channels in the development, maturation, and function of spermatozoa. Darszon A, Nishigaki T, Beltran C, Treviño CL. Physiol Rev. 2011. 91(4):1305-55.
“In higher animals, the beginning of new life and transfer of genetic material to the next generation occurs in the oviduct when two distinct gametes cells unite resulting in the formation of a zygote.”
Oviductal, endometrial and embryonic gene expression patterns as molecular clues for pregnancy establishment. Salilew-Wondim D, Schellander K, Hoelker M, Tesfaye D. Anim Reprod Sci. 2012. 134(1-2):9-18.
“The egg-to-embryo transition marks the initiation of multicellular organismal development and is mediated by a specialized Ca(2+) transient at fertilization.”
How to make a good egg!: The need for remodeling of oocyte Ca(2+) signaling to mediate the egg-to-embryo transition. Nader N, Kulkarni RP, Dib M, Machaca K. Cell Calcium. 2013. 53(1):41-54.
“It is intuitive that fertilization-the start of life-involves communication between a sperm cell and an egg.”
Membrane rafts regulate phospholipase B activation in murine sperm. Asano A, Nelson-Harrington JL, Travis AJ. Commun Integr Biol. 2013. 6(6):e27362.
"Fertilization occurs when sperm and egg recognize each other and fuse to form a new, genetically distinct organism."
Juno is the egg Izumo receptor and is essential for mammalian fertilization. Bianchi E, Doe B, Goulding D, Wright GJ. Nature. 2014. 508(7497):483-7.
“Fertilization is the culminating event in sexual reproduction and requires the recognition and fusion of the haploid sperm and egg to form a new diploid organism.”
Cross-species fertilization: the hamster egg receptor, Juno, binds the human sperm ligand, Izumo1. Bianchi E, Wright GJ. Philos Trans R Soc Lond B Biol Sci. 2015. 370(1661):20140101.
“Since a new individual is derived from the fusion of a single sperm and egg, we tested…”
Maternal non-Mendelian inheritance of a reduced lifespan? A hypothesis. Wilding M, Coppola G, De Icco F, Arenare L, Di Matteo L, Dale B. J Assist Reprod Genet. 2014. 31(6):637-43.
“The fusion of a sperm with an oocyte to form new life is a highly regulated event.”
An update on post-ejaculatory remodeling of the sperm surface before mammalian fertilization. Gadella BM, Boerke A. Theriogenology. 2015. 85(1):113-24.
“The time of our conception is when we are most vulnerable to survival and growing as a healthy human being.”
2015 RANZCOG Arthur Wilson Memorial Oration 'From little things, big things grow: The importance of periconception medicine'. Norman RJ. Aust N Z J Obstet Gynaecol. 2015. 55(6):535-40.
“Mammalian life begins with a cell-cell fusion event, i.e. the fusion of the spermatozoid with the oocyte”
State of the art in cell-cell fusion. Willkomm L, Bloch W. Methods Mol Biol. 2015. 1313:1-
“Mammalian life, with all its complexity comes from a humble beginning of a single fertilized egg cell.”
Mapping the journey from totipotency to lineage specification in the mouse embryo. Leung CY, Zernicka-Goetz M. Curr Opin Genet Dev. 2015. 34:71-6.
“As the start of a new life cycle, activation of the first division of the zygote is a critical event in both plants and animals.”
The anaphase-promoting complex initiates zygote division in Arabidopsis through degradation of cyclin B1. Guo L, Jiang L, Zhang Y, Lu XL, Xie Q, Weijers D, Liu CM. Plant J. 2016. 86(2):161-74.
"Human life begins with sperm and oocyte fusion."
The role of syncytins in human reproduction and reproductive organ cancers. Soygur B, Sati L. Reproduction. 2016. 152(5):R167-78.
“New parents anticipate their job begins at birth. Little do they know they have been exerting control within the baby’s first cell since fertilization.”
Parental Control Begins at the Beginning. Chu D. Genetics. 2016. 204(4):1377- 1378.
“In sexual organisms, division of the zygote initiates a new life cycle.”
ZYGOTE-ARREST 3 that encodes the tRNA ligase is essential for zygote division in Arabidopsis. Yang KJ, Guo L, Hou XL, Gong HQ, Liu CM. J Integr Plant Biol. 2017. 59(9):680-692.
“Aging is a developmental process that begins with fertilization and ends up with death involving a lot of environmental and genetic factors.”
Hutchinson-Gilford Progeria Syndrome: A Premature Aging Disease. Ahmed MS, Ikram S, Bibi N, Mir A. Mol Neurobiol. 2017. doi: 10.1007/s12035-017- 0610-7. [Epub ahead of print]
“At the end of oogenesis and spermatogenesis, both haploid gametes contain a single set of chromosomes ready to form the zygote, the first cell of the newly developing individual.”
“This is where it all started” - the pivotal role of PLCζ within the sophisticated process of mammalian reproduction: a systemic review. Gat I, Orvieto R. Basic Clin Androl. 2017. 21;27:9.
“Pronuclear/zygotic stage is the very first stage of life.”
.Epigenetic modifications and reprogramming in paternal pronucleus: sperm, preimplantation embryo, and beyond. Okada Y, Yamaguchi K. Cell Mol Life Sci. 2017. 74(11):1957-1967.
“Recognition between sperm and the egg surface marks the beginning of life in all sexually reproducing organisms.”
Structural Basis of Egg Coat-Sperm Recognition at Fertilization. Raj I, Sadat Al Hosseini H, Dioguardi E, Nishimura K, Han L, Villa A, de Sanctis D, Jovine L. Cell. 2017. 169(7):1315-1326.e17.
“the fertilized egg (zygote) is the beginning of a new diploid individual.”
Jones, R. E. Human Reproductive Biology, 4th edition. Waltham, MA. Elsevier, Academic Press, 2014, p. 169.
“Human development begins at fertilization when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male…Embryology is concerned with the origin and development of a human being from a zygote to birth.”
Keith L. Moore, Before We Are Born: Essentials of Embryology, 9th edition. Philadelphia, PA: Saunders, 2016. p. 1.
“The main results of fertilization are as follows: Restoration of the diploid number of chromosomes, half from the father half from the mother. Hence, the zygote contains a new combination of chromosomes different from both parents. Determination of the sex of the new individual. An X-carrying sperm produces a female (XX) embryo and a Y-carrying sperm produces a male (XY) embryo. Therefore, the chromosomal sex of the embryo is determined at fertilization.”
Sadler, T. W. Langman's Medical Embryology, 13th edition. Philadelphia, PA: Lippincott Williams & Wilkins, 2015. p. 42.
“Sexual reproduction occurs when female and male gametes (oocyte and spermatozoon, respectively) unite at fertilization.”
Dudek, R. W. Embryology, 4th edition. Philadelphia, PA. Lippincott Williams and Wilkins, 2008, p. 1.
“Fertilization is the sum of the cellular mechanisms that pass the genome from one generation to the next and initiate development of a new organism.”
Penetration, adhesion, and fusion in mammalian sperm-egg interaction. Primakoff P, Myles DG. Science. 2002. 296(5576):2183-5.
“Ca2+ signaling plays a crucial role in virtually all cellular processes, from the origin of new life at fertilization to the end of life when cells die.”
The cell cycle: a new entry in the field of Ca2+ signaling. Santella L, Ercolano E, Nusco GA. Cell Mol Life Sci. 2005. 62(21):2405-13.
“Representing the 60 trillion cells that build a human body, a sperm and an egg meet, recognize each other, and fuse to form a new generation of life.”
The immunoglobulin superfamily protein Izumo is required for sperm to fuse with eggs. Inoue N, Ikawa M, Isotani A, Okabe M. Nature. 2005. 434(7030):234-8.
“At fertilization, eggs unite with sperm to initiate developmental programs that give rise to development of the embryo. Defining the molecular mechanism of this fundamental process at the beginning of life has been a key question in cell and developmental biology.”
Signal transduction pathways leading to Ca2+ release in a vertebrate model system: lessons from Xenopus eggs. Sato K, Fukami Y, Stith BJ. Semin Cell Dev Biol. 2006. 17(2):285-92.
“Most readers of this review originated from a sperm-egg fusion event.”
Cell fusion during development. Oren-Suissa M, Podbilewicz B. Trends Cell Biol. 2007. 17(11):537-46.
“As representatives of the 60 trillion cells that make a human body, a sperm and an egg meet, recognize each other, and fuse to create a new generation.”
Sperm-egg fusion assay in mammals. Inoue N, Okabe M. Methods Mol Biol. 2008. 475:335-45.
“Sperm are remarkably complex cells with a singularly important mission: to deliver paternal DNA and its associated factors to the oocyte to start a new life.”
-Sperm chromatin: fertile grounds for proteomic discovery of clinical tools. Wu TF, Chu DS. Mol Cell Proteomics. 2008. 7(10):1876-86.
“A proper dialogue between spermatozoa and the egg is essential for conception of a new individual in sexually reproducing animals. Ca(2+) is crucial in orchestrating this unique event leading to a new life.”
Calcium channels in the development, maturation, and function of spermatozoa. Darszon A, Nishigaki T, Beltran C, Treviño CL. Physiol Rev. 2011. 91(4):1305-55.
“In higher animals, the beginning of new life and transfer of genetic material to the next generation occurs in the oviduct when two distinct gametes cells unite resulting in the formation of a zygote.”
Oviductal, endometrial and embryonic gene expression patterns as molecular clues for pregnancy establishment. Salilew-Wondim D, Schellander K, Hoelker M, Tesfaye D. Anim Reprod Sci. 2012. 134(1-2):9-18.
“The egg-to-embryo transition marks the initiation of multicellular organismal development and is mediated by a specialized Ca(2+) transient at fertilization.”
How to make a good egg!: The need for remodeling of oocyte Ca(2+) signaling to mediate the egg-to-embryo transition. Nader N, Kulkarni RP, Dib M, Machaca K. Cell Calcium. 2013. 53(1):41-54.
“It is intuitive that fertilization-the start of life-involves communication between a sperm cell and an egg.”
Membrane rafts regulate phospholipase B activation in murine sperm. Asano A, Nelson-Harrington JL, Travis AJ. Commun Integr Biol. 2013. 6(6):e27362.
"Fertilization occurs when sperm and egg recognize each other and fuse to form a new, genetically distinct organism."
Juno is the egg Izumo receptor and is essential for mammalian fertilization. Bianchi E, Doe B, Goulding D, Wright GJ. Nature. 2014. 508(7497):483-7.
“Fertilization is the culminating event in sexual reproduction and requires the recognition and fusion of the haploid sperm and egg to form a new diploid organism.”
Cross-species fertilization: the hamster egg receptor, Juno, binds the human sperm ligand, Izumo1. Bianchi E, Wright GJ. Philos Trans R Soc Lond B Biol Sci. 2015. 370(1661):20140101.
“Since a new individual is derived from the fusion of a single sperm and egg, we tested…”
Maternal non-Mendelian inheritance of a reduced lifespan? A hypothesis. Wilding M, Coppola G, De Icco F, Arenare L, Di Matteo L, Dale B. J Assist Reprod Genet. 2014. 31(6):637-43.
“The fusion of a sperm with an oocyte to form new life is a highly regulated event.”
An update on post-ejaculatory remodeling of the sperm surface before mammalian fertilization. Gadella BM, Boerke A. Theriogenology. 2015. 85(1):113-24.
“The time of our conception is when we are most vulnerable to survival and growing as a healthy human being.”
2015 RANZCOG Arthur Wilson Memorial Oration 'From little things, big things grow: The importance of periconception medicine'. Norman RJ. Aust N Z J Obstet Gynaecol. 2015. 55(6):535-40.
“Mammalian life begins with a cell-cell fusion event, i.e. the fusion of the spermatozoid with the oocyte”
State of the art in cell-cell fusion. Willkomm L, Bloch W. Methods Mol Biol. 2015. 1313:1-
“Mammalian life, with all its complexity comes from a humble beginning of a single fertilized egg cell.”
Mapping the journey from totipotency to lineage specification in the mouse embryo. Leung CY, Zernicka-Goetz M. Curr Opin Genet Dev. 2015. 34:71-6.
“As the start of a new life cycle, activation of the first division of the zygote is a critical event in both plants and animals.”
The anaphase-promoting complex initiates zygote division in Arabidopsis through degradation of cyclin B1. Guo L, Jiang L, Zhang Y, Lu XL, Xie Q, Weijers D, Liu CM. Plant J. 2016. 86(2):161-74.
"Human life begins with sperm and oocyte fusion."
The role of syncytins in human reproduction and reproductive organ cancers. Soygur B, Sati L. Reproduction. 2016. 152(5):R167-78.
“New parents anticipate their job begins at birth. Little do they know they have been exerting control within the baby’s first cell since fertilization.”
Parental Control Begins at the Beginning. Chu D. Genetics. 2016. 204(4):1377- 1378.
“In sexual organisms, division of the zygote initiates a new life cycle.”
ZYGOTE-ARREST 3 that encodes the tRNA ligase is essential for zygote division in Arabidopsis. Yang KJ, Guo L, Hou XL, Gong HQ, Liu CM. J Integr Plant Biol. 2017. 59(9):680-692.
“Aging is a developmental process that begins with fertilization and ends up with death involving a lot of environmental and genetic factors.”
Hutchinson-Gilford Progeria Syndrome: A Premature Aging Disease. Ahmed MS, Ikram S, Bibi N, Mir A. Mol Neurobiol. 2017. doi: 10.1007/s12035-017- 0610-7. [Epub ahead of print]
“At the end of oogenesis and spermatogenesis, both haploid gametes contain a single set of chromosomes ready to form the zygote, the first cell of the newly developing individual.”
“This is where it all started” - the pivotal role of PLCζ within the sophisticated process of mammalian reproduction: a systemic review. Gat I, Orvieto R. Basic Clin Androl. 2017. 21;27:9.
“Pronuclear/zygotic stage is the very first stage of life.”
.Epigenetic modifications and reprogramming in paternal pronucleus: sperm, preimplantation embryo, and beyond. Okada Y, Yamaguchi K. Cell Mol Life Sci. 2017. 74(11):1957-1967.
“Recognition between sperm and the egg surface marks the beginning of life in all sexually reproducing organisms.”
Structural Basis of Egg Coat-Sperm Recognition at Fertilization. Raj I, Sadat Al Hosseini H, Dioguardi E, Nishimura K, Han L, Villa A, de Sanctis D, Jovine L. Cell. 2017. 169(7):1315-1326.e17.
Timeline of major events:
The brain is there at 2 - 3 weeks after conception, the heart starts beating at 2 - 3 weeks after conception, this is before women even know they are pregnant, limb buds form at 3 - 4 weeks, the cerebral hemispheres and cerebellum are there and begin rapid growth by 4 and a half weeks, eyes are there at 4 and a half weeks, movements start by 5 and a half weeks, brain waves are detectable to us by 6 weeks, the face withdraws from light touch around the mouth at 6 weeks, eyelids are present by 6 weeks, they hiccup by 7 weeks, females have ovaries at 7 weeks, the testes begin to differentiate in males at 7 weeks, all the organs are there at 8 weeks, they roll over and open and close their mouths and squint and have complex responses to touch by 8 weeks, male fetuses make testosterone in their testes at 8 weeks, the neurons synapse in the cerebral cortex by 8 and a half weeks (meaning the cerebral cortex is there before), female fetuses have identifiable uteruses and early reproductive cells in their ovaries at 9 weeks, they yawn by 9 and a half weeks, and fingerprints are visible by 10 weeks. Most abortions happen at 8 weeks on up. You can watch the heart beating at 4 and a half weeks after conception right here. http://www.ehd.org/movies.php?mov_id=21
The brain is there at 2 - 3 weeks after conception, the heart starts beating at 2 - 3 weeks after conception, this is before women even know they are pregnant, limb buds form at 3 - 4 weeks, the cerebral hemispheres and cerebellum are there and begin rapid growth by 4 and a half weeks, eyes are there at 4 and a half weeks, movements start by 5 and a half weeks, brain waves are detectable to us by 6 weeks, the face withdraws from light touch around the mouth at 6 weeks, eyelids are present by 6 weeks, they hiccup by 7 weeks, females have ovaries at 7 weeks, the testes begin to differentiate in males at 7 weeks, all the organs are there at 8 weeks, they roll over and open and close their mouths and squint and have complex responses to touch by 8 weeks, male fetuses make testosterone in their testes at 8 weeks, the neurons synapse in the cerebral cortex by 8 and a half weeks (meaning the cerebral cortex is there before), female fetuses have identifiable uteruses and early reproductive cells in their ovaries at 9 weeks, they yawn by 9 and a half weeks, and fingerprints are visible by 10 weeks. Most abortions happen at 8 weeks on up. You can watch the heart beating at 4 and a half weeks after conception right here. http://www.ehd.org/movies.php?mov_id=21
Here is the development timeline: (or go to ehd.org and hit the prenatal timeline button)
