Contrary to what many non-scientists believe, human beings are not constructed in the womb - they develop. In fact, all the major organ systems are initiated within the first few weeks after conception. The process of embryonic development is a continuous process, with no obvious point at which the foetus magically becomes a "person." In fact, the development process continues well after birth, including many characteristics that determine our personality or personhood.
Development of the baby in womb in weeks.
Medical Illustration Copyright © 2010 Nucleus Medical Art, All rights reserved.
What are the stages in human embryonic development? Science tells us that the heart of the human foetus begins to form 18 days after conception. There is a measurable heart beat 21-24 days after conception. This is only 7-10 days after a woman would expect to begin her menstrual cycle. Since most women have cycles that can vary by this amount, they do not discover they are pregnant until after this point. Therefore, all abortions stop a beating heart, even "early" abortions. However, most abortions do not occur until 4-6 weeks after the foetus begins to form. The human brain begins to form on day 23 and is formed enough to produce brain waves by 6 weeks, which means that most abortions destroy a functioning human brain.
What do embryology books have to say about human development?
- The Developing Human: Clinically Oriented Embryology (pp 2-18): "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). 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."
- Essentials of Human Embryology (pp. 1-17): "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 ... resulting in the formation of a zygote containing a single diploid nucleus. Embryonic development is considered to begin at this point... This moment of zygote formation may be taken as the beginning or zero time point of embryonic development."
- Human Embryology & Teratology (pp. 5-55): "Fertilization is an important landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed... Fertilization is the procession of events that begins when a spermatozoon makes contact with a secondary oocyte or its investments... The zygote ... is a unicellular embryo... "
What do Medical Doctors Say?
"I have learned from my earliest medical education that human life begins at the time of conception."
- Dr. Alfred Bongioanni (University of Pennsylvania):
"after fertilization has taken place a new human being has come into being."
-Dr. Jerome LeJeune (University of Descartes):
"By all criteria of modern molecular biology, life is present from the moment of conception."
- Dr. Hymie Gordon (Mayo Clinic):
"It is scientifically correct to say that an individual human life begins at conception"
- Dr. Micheline Matthews-Roth (Harvard University Medical School):
Human Embryology 101
- Foetal heart begins to form 18 days after conception
- Measurable heart beat 21-24 days after conception
- Foetal brain begins to form on day 23
- Brain waves produced by 6 weeks
- Human life begins at conception
- Human development proceeds rapidly (all organs and systems are in place by week 8)
- Abortion stops a beating heart
- Most abortions occur after the foetus exhibits measurable brain waves