When Does Life Begin?

 This question reminds me of a quote from p. 57 of Science Made Stupid:  "One of the mammals' evolutionary advantages was that they bore their young alive.  As research has conclusively shown, animals that bore their young dead generally got nowhere."

From a scientific point of view, life does not begin at birth, nor when one registers to vote as a Democrat, as some seem to believe.  But it also does not begin at conception, as is often stated.  It began, apparently, only once, and that was more than 3.7 billion years ago.  Ever since then, life has been passed down to succeeding generations with no gap in between.  

Asking when a human organism comes into being is a different question.  That is the question for which the scientific answer is, generally, "at conception"; I say generally because some (it must be emphasized) purely theoretical questions are posed by the production of identical twins, triplets, etc.  These questions may be interesting to think about, but they do not provide a license to play with the lives of humans at an embryonic stage of development.  But my main point is that Catholics and others who care about the truth need to be careful with the language we use.   We are told that no one puts old wine in new wineskins, but we have no alternative to putting old biological life into new organisms.

It should also go without saying that biology is not equipped to detect the soul.  The existence of the soul can be derived from philosophy, as Aristotle did it, but not from the natural sciences, so the immediate creation of each spiritual soul by God cannot be proved or refuted by science.