Re: Abortion okay prior to implantation?

Glenn Morton (grmorton@waymark.net)
Thu, 05 Feb 1998 21:51:08 -0600

At 09:52 PM 2/5/98 -0500, bgreuel@bstream.com wrote:
>John W Burgeson used the following statements to argue that "abortion before
>implantation is not proscribed":
>
>1. A zygote may "split" along the way
>2. Two zygotes may "fuse" along the way
>
>I'm having trouble following the logic connecting these statements to the above
>argument about abortion. But first of all, let's make sure we can agree on
some
>terminology.
>
>Zygote = a fertilized egg. The only splitting it does is to cleave into a
>two-celled embryo. The cells of this two-celled embryo could potentially
>separate from one another to give rise to two separate embryos (identical
>twins), but this happens extremely rarely. Most instances of identical
twinning
>occur as a result of subdivision of the inner cell mass at the blastocyst stage
>of development.

HEre is a technical discussion of what they are talking about.
Experimentally you can take two or three embryos and form a single individual.

Where is the soul
"If most of the cells of the blastocyst give rise to the trophoblast,
exactly how many cells actually form the embryo? ONe way to answer this
question is to produce ALLOPHENIC MICE. Allophenic mice are the result of
two early-cleavage (usually 4- or 8-cell) embryos that have been aggregated
together to form a composite embryo. As shown in Figure 28, the zonae
pellucidae of two genetically different embryos are removed and the embryos
brought together to form a common blastocyst. These prepared blastocysts are
implanted into the uterus of the foster mother. When they are born, the
allophenic offspring have some cells from each embryo. This is readily seen
when the aggregated blastomeres come from mouse strains that differe in their
coat colors."~Scott F. Gilbert, Developmental Biology (Sunderland: Sinauer
Assoc. Inc., 1991), p. 95
**
where is the soul
The experimental data of Mintz (1970) are that 73 percent of the double
embryos yield allophenic mice, thus suggesting that three blastomeres of the
blastocyst produce the entire embryo. Markert and Petters (1978) have hown
that three early 8-cell embryos can unite to form a common compacted morula
and that the resulting mouse can have the coat colors of the three different
strains. Therefore, while it is not certain that three is the absolute number
of blastomeres that form the embryo, we can be fairly certain that the number
is not much greater and that most of the cells of the blastocyst never
contribute to the adult organism."~Scott F. Gilbert, Developmental Biology
(Sunderland: Sinauer Assoc. Inc., 1991), p. 95-96

glenn

Adam, Apes, and Anthropology: Finding the Soul of Fossil Man

and

Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm