Biology and babies

by Richard G. Rose, Professor Emeritus, West Valley College Biology Department

Biology is the knowledge, or science, of life.  If rational biology was the only factor in our attitude toward unborn babies, there would be much less debate about caring for and protecting them.  But irrational emotions and personal philosophies play a huge additional role in our attitudes and choices.  What does biology, by itself, tell us about life before birth, beginning with the single, fertilized egg cell?

First, that this new life is a separate and distinct individual from all others.  Modern molecular genetics has taught us that this new person’s specific pattern of genetic information is not duplicated among all the other people on earth and is clearly distinct from the mother.  Twins result from the separation of developed cells slightly later in development.  Christianity has long taught that each individual is unique and valuable.  And now biology has confirmed that uniqueness.  We may debate when this new life becomes human, but we can no longer argue about it being a separate individual from the very beginning.

Second, we now know that the whole structure and function of the independent adult is laid out in the DNA blueprint of this one original cell, including contributions from each parent.  Although the realities of birth and adulthood lie in the distant future, no additional information or specifications need to be added.  The adult who results from this single cell may be modified as the complexities of physical, mental, emotional and spiritual aspects develop.  But all the programming instructions for the nervous system and all the other specific cell types and complex systems needed to be a human adult are already present.  We still have much to learn about the ways that cells control what they will become, including stem cells.

Third, we have learned from biological study of human development that all these systems develop at surprisingly early stages.  There have been attempts to define pregnancy as beginning only when the developing embryonic baby has attached to the mother’s uterine lining.  Yet even before this, complex and irreversible developments have occurred – nerve cells are laid down and the brain and spinal cord begin to develop, our three basic tissue layers have separated, and the support structures needed during pregnancy (placenta, etc.) are developing so that the mother can supply needed food and oxygen. Heart tissue even begins to beat about day #23, and before the month is out, the embryo is a recognizable, tiny human body.  Such knowledge of early development heightens concerns about chemical and other stresses undergone by the mother during this critical time of rapid development.

Human Fetal Development

Fourth, we are learning more and more about a developing baby’s responses to stimuli, both by nervous system and endocrine reactions, although there is not yet a firm scientific consensus in this area.  In 1996, English physiologist Peter McCullagh spoke in support of a pro-life position to the British Parliament. He said, “At what stage of human prenatal development are those anatomical structures subserving the appreciation of pain present and functional? The balance of evidence at the present time indicates that these structures are present and functional before the tenth week of intrauterine life.”  Studies of the specific brain structures which are the means by which pain is perceived indicate to others that they are not formed in a fetus until 20 weeks or more.  However, there are many anecdotal descriptions of fetal response to loud noises, music, mother’s stress level, and other stimuli to indicate that sensory systems in the brain are active and processing at very early stages.

Finally, progress in medical sciences in the last thirty-seven years has resulted in ever shorter duration before the developing baby can survive outside the womb.  In 1973, that limit was sometime after the 24th week of pregnancy.  Now that time is down to 22 weeks and still being reduced.  There are problems, of course.  Babies at this early stage have barely formed respiratory systems.  They need special medical support systems, which are also being developed.  Sonograms and other measures of fetal weight can be used to indicate the state of development of the baby.  Yet these biological advances are dismissed by some medical ethicists and abortion advocates, who say that other, non-quantifiable factors should be used instead.  Such arguments are used most loudly in arguments about late-term abortions, when survival outside the womb is clearly possible and where avoidance/pain reactions are clearly observable.

With areas of medical science, genetics, human development and other parts of the biological sciences giving us so much new information over the last three decades, it is important to make rational use of this new knowledge in evaluating the fate of a developing baby.

Fetal image from www.creationwiki.org/Developmental_Biology
Foer, Franklin.  “Fetal Viability”  Slate Magazine. Posted online May 25, 1997
McCullagh, Peter.  Foetal sentience.  London: All-Party Parliamentary Pro-Life Group (1996).
Dr. McCullagh is a Senior fellow in developmental physiology at the John Curtin School of Medical Research, Australian National University. This report was reprinted in the Catholic Medical Quarterly, XLV11 no 2, November 1996, p6.

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