Saturday, October 28, 2006

Reply to demimondian

demimondian commented:

    A human fetus—much less a human embryo—is, in fact, not an organism. Wiki has a nice suymmary of the definition:

    In biology and ecology, an organism (in Greek organon = instrument) is a living complex adaptive system of organs that influence each other in such a way that they function in some way as a stable whole.

    An organism is in a non-equilibrium thermodynamic state, maintaining a homeostatic internal environment, and a continuous input of energy is required to maintain this state.

    The key word is “stable”—neither an embryo, or a human fetus before a certain stage of development, is capable of functioning as a stable whole. The “mother + zygote” pair is an organism, but the zygote itself is emphatically not.

    Your core hypothesis is, therefore, not true. That doesn’t invalidate your conclusion, but it does rubbish your argument.

This is the easiest to refute: according to embryology -- and what field of science is more relevant? -- the conceptus at every stage is a human organism. Consult the texts cited by Prof. George as found in the previous post.

Apart from that, demimondian errs in stating that the the fetus and embryo are not stable: the human being at both stages is an integrated, self-directed entity. Can it survive outside a particular environment, in which it finds sustinance? Of course not, but neither can any organism. I think he's misunderstanding the contextual meaning of stability.

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