[Magdalen] Sex determination (was something else)

[Rick Mashburn]

This has been a very interesting discussion!

Peace, Rick
bummed today because I noticed gray hairs on Malcolm's face this morning
On May 6, 2016 12:53 PM, "Jay Weigel" <jay.weigel at gmail.com> wrote:

> Exactly. I have a friend who has Klinefelter Syndrome (47,XXY). He is, for
> all intents and purposes, male. Tall, slender, possessed of a rather
> high-pitched speaking voice (in the tenor range), but indistinguishable
> from other males generally. He was diagnosed sometime in his teens. He is
> also gay, but they aren't all by any means.
>
> There are also people who are born intersex, that is, with the sex
> characteristics (including genitals, gonads and chromosome patterns) that
> do not fit typical binary notions of male or female bodies. Intersex traits
> are not always apparent at birth; some babies may be born with ambiguous
> genitals, while others may have ambiguous internal organs (testes and
> ovaries). Others will not become aware that they are intersex—unless they
> receive genetic testing—because it does not manifest in their phenotype.
> This occurs somewhere between 1:15,00 and 1:17,00 births, although it might
> be more frequent because many go undiagnosed because they do not fit the
> outward patterns. During my short time in neonatal in a small town
> hospital, we had two babies who were born intersex, so I think it might be
> more frequent than those numbers.
>
> On Fri, May 6, 2016 at 1:33 PM, cady soukup <cadyasoukup at gmail.com> wrote:
>
> > Basically, no -
> >
> > There are genetically-based variants (xxy, xyy, etc.), genetic mosaics
> > (more than one genetic expression of DNA in one individual), and many
> > ways to express or not express the underlying genes (penetration,
> > expression, other terms & conditions). That's what makes genetics
> > interesting.
> >
> > The majority tends to be expressed normally. In the specifics, not true.
> >
> > I've met & known variants (xxy, xyy) who have expressed relatively
> > normally. It's hard to know for sure unless you absolutely know an
> > individual's genetics, physiology, and life expression.
> >
> > Cady
> >
> > On 5/6/16, Rick Mashburn <ricklmashburn at gmail.com> wrote:
> > > I was horrible at science in school but isn't it really genetic? The
> > fetus
> > > is either xx or xy from conception, right? Wouldn't that control the
> > > physical development?
> > >
> > > Peace, Rick
> > > On May 6, 2016 8:32 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.
> > >>
> > >>
> > >
> >
>