Recently, I have read opinions that the beginning of biological life is either a fuzzy proposition or as Dr. Mark Hoofnagle asserts here is not a true beginning at all. I am still working on a response, but Wesley Smith posted a comment under this post at Second Hand Smoke that I thought was pretty right on all by itself. He is responding to a comment that “the beginning and ends of human life are not bright lines but complex processes.”
I am posting the comment in its entirety with Wesley’s permission:
The "complication" does not come from biology, but from philosophy, ideology. Biologically we know when a new human organism has come into being: it is upon the completion of the fertilization process in which the new organism has its own genome and is a unique, discrete, integrated individual. And don't talk twinning: That is merely one of the potentialities possessed by the unique organism for a period of time in its development. Indeed,if twinning occurs, then there are two unique organisms. But the capacity to twin does not mean that the embryo is not a living organism.
Death too is a biological process in which this organism ceases to operate in an organized, integrated fashion. In other words, even if there are still some cells that are alive, after death, it is not an organism any longer. (Thus, if you remove the heart and it keeps beating, this does not mean that the heart is a living organism. It is merely a heart that can beat for a time. Similarly, the fact that hair grows for a bit after life ceases, does not make the cadaver alive since it is not acting as an integrated organism.
We complicate what constitutes the beginning and end of human life for reasons of utility and ideology. (Ironically, this is generally done by people who claim the mantle of rationality and as defenders of science.) We want to be able to engage in ESCR, and so we say that embryos are really only pre-embryos that are mere chemical processing cell bundles. We want to harvest organs, so we say that a PVS patient is really dead.
But these arguments aren't scientific. Indeed, it is postmodern biology--a corruption of science--because the biological facts don't matter, or better stated, get in the way of what we want to do and get a good night's sleep. So, we adhere to the narrative instead of the facts.
The questions of birth and death, biologically, is not really all that complicated which is why I would trust a plumber with these matters far more than a Ph.D.