posted by jmog
Did you really just say it’s undisputed and then quote something that says “many scientists”? You realize “many” is colloquially used to mean a lot but less than half right?
Later in the paragraph that you neglected to reference it says that scientists generally agree which would be the sort of universe you're referring to. Oddly enough I didn't think it'd be this ridiculous to try and lay it out for you since you're the pro-life person and it is pro-life people who always say "life begins at conception" with conception being fertilization but I have the day off today and it's raining so I will provide more sources.
Here's a conservative/pro-life medical society - The American College of Pediatricians' official position:
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.
The U.S. Department of Health and Human Services' Position under Trump is now officially that human life begins at conception:
https://www.hhs.gov/about/news/2019/01/18/hhs-is-committed-to-protecting-life-and-conscience.html
American Association of Pro-Life Obstetricians and Gynecologists:
Dr. Joseph DeCook, executive director of the American Association of Pro-life Obstetricians and Gynecologists, a group of about 2,500 members, said an embryo is a living human being at the moment of fertilization.
“There’s no question at all when human life begins,” said DeCook, a retired obstetrician-gynecologist. “When the two sets of chromosomes get together, you have a complete individual. It’s the same as you and I but less developed.”
Pregnancy begins when the embryo is implanted on the uterine wall, he said.
“But we’re not talking about pregnancy,” he said. “The question you have to focus on, is when does meaningful, valuable human life begin? That’s with the union of the two sets of chromosome. You have a complete human being that begins developing.”
After fertilization, “it’s a complete human being in the process of development. It deserves protection of the law.”
The following is from a paper directly on point - "A scientific view of when life begins" produced by the pro-life Charlotte Lozier Institute:
The conclusion that human life begins at sperm-egg fusion is uncontested, objective, based on the universally accepted scientific method of distinguishing different cell types from each other and on ample scientific evidence (thousands of independent, peer-reviewed publications). Moreover, it is entirely independent of any specific ethical, moral, political, or religious view of human life or of human embryos. Indeed, this definition does not directly address the central ethical question surrounding the embryo: What value ought society place on human life at the earliest stages of development? A neutral examination of the evidence merely establishes the onset of a new human life at a scientifically well-defined “moment of conception,” a conclusion that unequivocally indicates that human embryos from the one-cell stage forward are indeed living individuals of the human species; i.e., human beings. *Dr. Condic is Associate Professor of Neurobiology and Adjunct Professor of Pediatrics at the University of Utah School of Medicine. She is also Director of Human Embryology instruction for the Medical School and of Human Neuroanatomy for the Dental School.
https://lozierinstitute.org/a-scientific-view-of-when-life-begins/
Here's from a pro-evolution organization that presumably does not have the moral opposition to abortion that pro-life orgs do:
In the scientific debates of our day, it’s important to distinguish debates about scientific facts from debates about the ethical or metaphysical consequences of scientific facts.
That human life begins at conception is a scientific fact, and has been recognized as such since the early 19th century when fertilization of the ovum by the sperm was first observed in the laboratory. That life begins at conception is as much a scientific fact as heliocentrism, and the fact that the earth is round, and that water is H2O.
A new human being comes into existence at the fusion of the egg and the sperm. The new human being develops through stages, and at each stage of human development — zygote, embryo, fetus, neonate, infant, child, adolescent, adult — the individual is a human being. There is no scientific debate about this.
The legal protections offered to human beings at various stages of life are a matter of ethics, not a matter of science. From the perspective of science, human life begins at conception and ends at death.
And finally, some literature:
"Development begins at fertilization when a sperm fuses with an ovum to form a zygote; this cell is the beginning of a new human being."
Moore, Keith L., The Developing Human: Clinically Oriented Embryology, page 12, W.B. Saunders Co., 2003
"In that fraction of a second when the chromosomes form pairs, 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., 1974
"A new individual is created when the elements of a potent sperm merge with those of a fertile ovum."
Encyclopedia Britannica, "Pregnancy," page 968, 15th Edition, Chicago 1974
"Development begins with fertilization, the process by which the male gamete, the sperm, and the femal 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
""Although life is a continuous process, fertilization (which, incidentally, is not a 'moment') 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."
Ronan O'Rahilly and Fabiola Müller, Human Embryology and Teratology, 3rd edition. New York: Wiley-Liss, 2001. p. 8.
I suppose I could go on but hey - you deny climate change despite the consensus so I suppose I shouldn't waste too much more time here. I thought the evolution org put it well - it is a scientific fact that there's a new human being at conception. Continue to deny the fact to preserve your inconsistent beliefs if you want. The metaphysical consequences of that fact and the decision on whether to grant a newly conceived human being that is a zygote the same protection as the Mother is a matter of ethics.