[Magdalen] Sex determination (was something else)

[AT&T]

I realize I misspelled Malpighian. 

Jim Handsfield 
Sent from my iPhone

> On May 6, 2016, at 9:32 AM, James Handsfield <jhandsfield at att.net> wrote:
> 
> There’s a difference between the genetics and the anatomical development of an embryo or fetus.  You are right that an embryo is male or female in most cases.  Genetic confusion does occur, but it’s usually fatal long before term.
> 
> The argument that an embryo or fetus becomes a different sex in development is also mistaken.  It’s based on the long discredited idea that ontogeny recapitulates phylogeny.  The anatomical sex differences are homologous in that they arise from the same embryonic structures.  There are two embryonic reproductive systems in mammals - the Malphigian system and the Wolffian system.  The Malphigian system becomes dominant in males and the Wolffian system in females, but both systems exist in both sexes.
> 
> Alleluia!  Christ is risen!
> 
> James Handsfield
> jhandsfield at att.net
> 
>> On May 6, 2016, at 4:02 AM, Sibyl Smirl <polycarpa3 at ckt.net> wrote:
>> 
>> That's not the way that I learned it. At least, 99.9% of the time, there's an egg and a sperm.  The sperm contains either an x chromosome or a y chromosome, not both.  The egg contains an x chromosome, one of two possibles (the mother has two matching ones, which divide to produce the egg.)  Conception occurs when the egg and the sperm meet: an X matches with a y, or with another x, so that if it happens to be a Y sperm, conception results in an XY (male) combination, and if it's an X sperm, you get an XX combination (female).  So from the moment there's a fertilized egg, it's either a girl or a boy, even if it's only one or a few cells, and you can't yet tell by looking until much later, unless you want to kill it and have an electron microscope handy.
>