What Is the Unborn, Biologically Speaking?

Contents of This Page

  • Opinions of Embryologists
  • See the Unborn in Living Color
  • New Research Relevant to This Topic
  • Opinions of Pro-Choice Philosophers
  • Explanations from Scientists and Philosophers
  • Ted Talk: Visualization from Alexander Tsiaris

Opinions OF Embryologists

  • "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 & Teratology, 3rd ed. (New York: Wiley-Liss, 2001), p. 8
  • “Zygote. This cell, formed by the union of an oocyte and a sperm, is the beginning of a new human being (i.e., an embryo).”  -- Keith L. Moore and T.V.N. Persaud, Before We Are Born: Essentials of Embryology and Birth Defects, Sixth Edition (Philadelphia: Saunders, 2003), p. 2
  • “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 Embryology, 9th Edition (London: Lippincott Williams & Wilkins, 2004), p. 3



    More video content is available from the Endowment for Human Development (EHD).

    Note that EHD has created great apps for many common mobile devices that allow you to watch (and show others to whom you're talking) videos of the unborn at many stages of development.  JFA highly recommends using these apps and donating to EHD to help EHD continue providing this excellent free, life-saving content.

    New Research Relevant to This Topic

    Opinions of Pro-Choice Philosophers

    • “Perhaps the most straightforward relation between you or me on the one hand and every human fetus from conception onward on the other is this: All are living members of the same species, homo sapiens. A human fetus, after all, is simply a human being at a very early stage in his or her development.”  -- David Boonin, A Defense of Abortion (New York: Cambridge University Press, 2003), p. 20
    • “It is possible to give ‘human being’ a precise meaning. We can use it as equivalent to ‘member of the species Homo sapiens’. Whether a being is a member of a given species is something that can be determined scientifically, by an examination of the nature of the chromosomes in the cells of living organisms. In this sense there is no doubt that from the first moments of its existence an embryo conceived from human sperm and eggs is a human being; and the same is true of the most profoundly and irreparably intellectually disabled human being, even of an infant who is born anencephalic –literally, without a brain.”  -- Peter Singer, Practical Ethics, 2nd ed. (Cambridge: Cambridge University Press, 1993), 85-86.
    • “A human fetus is not a nonhuman animal; it is a stage of a human being.“  -- Wayne L. Sumner, Abortion and Moral Theory (Princeton: Princeton University Press, 1981), p. 10

    Explanations from Scientists and Philosophers


      TED Talk: Visualization from Alexander Tsiaris

      Warning: This video includes some graphic imagery and female nudity associated with the moment of birth.  Also includes some nudity associated with the physiology of the unborn and the pregnant woman.

      Correction: The video caption at 12 weeks from fertilization states "penis indifferent...girl or boy yet to be determined." While it is true that physiologically one can't see a distinction between male or female reproductive organs early in development, the statement in the video is misleading.  The sex of the human is determined at fertilization, when the chromosomes in the 23rd position (in normal cases) are either XX (girl) or XY (boy).