Friday, September 30, 2011

Missing the point about the beginning of life

At the Statesman Journal's science blog, Susie Bodman (an editor at the paper) responds to the pro-life contention that life begins at conception:
As a biology student, I'm sorry, but the stipulation that "life begins at conception" is laughable to me. However, it's not for reasons you might assume — that I'm a godless scientist-in-the-making, a stereotypically liberal journalist, a pro-choice protagonist, a fire-breathing feminist or whatever else you might conjure up.

It comes from how biologists define life and distinguish it from inanimate things, such as rocks. Living organisms are characterized by having the capacity for growth, reproduction, functional activity and continual change.

A single cell is a form of life, and guess what eggs and sperms are. Yep, that's right. They are CELLS.

If eggs and sperm are already alive, well, then to a biologist life exists BEFORE conception.

Also, if those egg and sperm cells are made by you, and you were at one time conceived from egg and sperm cells arising from a couple who were conceived from egg and sperm cells and so on, so long as you're not at the end of an extinct lineage, life really is CONTINUOUS until you get back to the very first cell that formed on Earth.

Therefore, life doesn't just begin at conception. It's more like life BEGAN with the first cell 3.8 billion years ago.
Bodman really, laughably, misses the point. When we say "life begins at conception," we mean (obviously, I thought) that the life of an individual human being begins at conception. Biological life in general is continuous, as she notes; even the sperm and egg are "living." But the sperm and egg are mere parts of larger organisms, not human beings themselves. When they unite a new single-celled organism (the zygote) is formed -- a member of our species at the earliest stage of development -- who (given an adequate environment and nutrition) will actively develop himself or herself toward maturity. The textbook Human Embryology & Teratology explains: "Although life [defined broadly] is a continuous process, fertilization is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed."

In short, Bodman apparently has yet to learn how biologists distinguish organisms (e.g., you, me, an embryo) from biological entities that are not organisms (e.g., sperm, egg, a strand of my hair).

That a distinct, living and whole (though immature) human organism comes into existence at conception is a matter of biological fact. Embryology textbooks and leading experts overwhelmingly confirm this:
The Developing Human: Clinically Oriented Embryology: "Human development begins at fertilization when a male gamete or sperm (spermatozoon) unites with a female gamete or oocyte (ovum) to form a singe cell—a zygote. This highly specialized, totipotent cell marked the beginning of each of us as a unique individual."

Langman's Embryology: "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."

Before We Are Born: Essentials of Embryology and Birth Defects: "Human development begins when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male. … This cell [the zygote], formed by the union of an oocyte and a sperm, is the beginning of a new human being."

Dr. Jerome LeJeune, discoverer of Down syndrome chromosome: "To accept the fact that after fertilization has taken place a new human has come into being is no longer a matter of taste or opinion. The human nature of the human being from conception to old age is not a metaphysical contention; it is plain experimental evidence."

Dr. Micheline Matthews-Roth, Harvard University Medical School: "It is scientifically correct to say that an individual human life begins at conception, when egg and sperm join to form the zygote, and this developing human always is a member of our species in all stages of its life."
Learn more here.