Discussion:
Bi-gendered cardinal
(too old to reply)
J. Clarke
2021-02-28 02:11:25 UTC
Permalink
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.

<https://www.snopes.com/fact-check/photo-dual-gender-cardinal/>
Dorothy J Heydt
2021-02-28 03:47:32 UTC
Permalink
Post by J. Clarke
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.
<https://www.snopes.com/fact-check/photo-dual-gender-cardinal/>
Yup, I've seen that one before. It has (so it's said) one ovary
and one testicle.
--
Dorothy J. Heydt
Vallejo, California
djheydt at gmail dot com
Www.kithrup.com/~djheydt/
Quadibloc
2021-02-28 07:29:35 UTC
Permalink
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.
I certainly never heard of this either.

When I first saw the article, which mentioned that this phenomenon
is noted in only a few species, I thought... ah, instead of these birds
using the XY system of sex selection, like we do, perhaps they're an
XO species - so during the initial cell division, one of the X chromosomes
got lost, creating a half-male half-female bird.

But it turns out this is not the case. Instead, cardinals belong to the ZW
sex selection system. In that one, a male is ZZ, and a female is ZW; the
Z chromosome is big and rich with genes, like an X chromosome, and
the W is just a stub, like a Y chromosome.

So their sex selection is exactly like ours, except that the resultant sex
of the individual is the opposite. Thus, I am at a loss as to why
gynandromorphy is possible in cardinals and not in humans and creatures
like them (other forms of hermaphroditism are possible in humans, but
not that one).

John Savard
J. Clarke
2021-02-28 12:54:13 UTC
Permalink
On Sat, 27 Feb 2021 23:29:35 -0800 (PST), Quadibloc
Post by Quadibloc
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.
I certainly never heard of this either.
When I first saw the article, which mentioned that this phenomenon
is noted in only a few species, I thought... ah, instead of these birds
using the XY system of sex selection, like we do, perhaps they're an
XO species - so during the initial cell division, one of the X chromosomes
got lost, creating a half-male half-female bird.
But it turns out this is not the case. Instead, cardinals belong to the ZW
sex selection system. In that one, a male is ZZ, and a female is ZW; the
Z chromosome is big and rich with genes, like an X chromosome, and
the W is just a stub, like a Y chromosome.
So their sex selection is exactly like ours, except that the resultant sex
of the individual is the opposite. Thus, I am at a loss as to why
gynandromorphy is possible in cardinals and not in humans and creatures
like them (other forms of hermaphroditism are possible in humans, but
not that one).
It might be anatomical--a fetus that forms with half a penis and half
a vagina might not survive the experience. Avian reproductive anatomy
seems to be a bit more subtle in most species. So I find myself
wondering if there are stillbirths in humans with this particular
construction.
Quadibloc
2021-02-28 14:02:15 UTC
Permalink
Post by J. Clarke
It might be anatomical--a fetus that forms with half a penis and half
a vagina might not survive the experience. Avian reproductive anatomy
seems to be a bit more subtle in most species. So I find myself
wondering if there are stillbirths in humans with this particular
construction.
That is one possibility.

If my simplistic analysis that gynandromorphy would be more likely in
a creature using the X0 sex chromosome system than one using the
XY sex chromosome system makes sense, I thought of something else
that might be going on.

For a human being to be half XX and half XY due to something going
wrong in the first cell division, that human would have to have originated
from an XXY single-cell zygote. So _two_ very rare events would have to
have happened.

Whereas if a being had the X0 system, gynandromorphy could result simply
from the X going to one of the two new cells only.

Although in humans the Y chromosome is much smaller than the X chromosome,
it still does contain some important genes.

So it could be that cardinals are further along the line of evolution from a ZW
system to a Z0 system, and the W chromosome in them is such a small stub that
a Z0 cardinal can still survive as an almost-normal female.

John Savard
Quadibloc
2021-02-28 19:11:31 UTC
Permalink
In any case, in reading up on the topic, I've learned interesting things.

Such as the WXY sex-determination system of the Platy (Xiphophorus
maculatus) in which WY, WX, and XX individuals are female, and XY
and YY individuals are male. All six possible forms of mating occur
in the wild.

An XX/YY mating gives rise to only XY male progeny.
A WX/XY mating gives rise to WX, WY, and XX female progeny, and XY male progeny
All other combinations give an even sex ratio.

Assuming all forms of that fish are equally fertile and equally fit, and the sex ratio is
the Mendelian one (not necessarily true; the Mendelian one for humans would be 1:1,
but it is in fact 1.05:1 in favor of males), what would the equlibrium sex ratio for this
species be?

John Savard
Dorothy J Heydt
2021-02-28 16:01:58 UTC
Permalink
Post by J. Clarke
On Sat, 27 Feb 2021 23:29:35 -0800 (PST), Quadibloc
Post by Quadibloc
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.
I certainly never heard of this either.
When I first saw the article, which mentioned that this phenomenon
is noted in only a few species, I thought... ah, instead of these birds
using the XY system of sex selection, like we do, perhaps they're an
XO species - so during the initial cell division, one of the X chromosomes
got lost, creating a half-male half-female bird.
But it turns out this is not the case. Instead, cardinals belong to the ZW
sex selection system. In that one, a male is ZZ, and a female is ZW; the
Z chromosome is big and rich with genes, like an X chromosome, and
the W is just a stub, like a Y chromosome.
So their sex selection is exactly like ours, except that the resultant sex
of the individual is the opposite. Thus, I am at a loss as to why
gynandromorphy is possible in cardinals and not in humans and creatures
like them (other forms of hermaphroditism are possible in humans, but
not that one).
It might be anatomical--a fetus that forms with half a penis and half
a vagina might not survive the experience. Avian reproductive anatomy
seems to be a bit more subtle in most species.
What they've got is a cloaca (Latin for "sewer"), into which
urine, feces, and reproductive material are all dumped. Since
birds' eggs are fertilized internally before the shell is formed,
you may ask, how do the sperm reach the ova? Well, it's
described as "the cloacal kiss...."
--
Dorothy J. Heydt
Vallejo, California
djheydt at gmail dot com
Www.kithrup.com/~djheydt/

So I find myself
Post by J. Clarke
wondering if there are stillbirths in humans with this particular
construction.
Christian Weisgerber
2021-02-28 15:31:26 UTC
Permalink
Post by Quadibloc
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.
I certainly never heard of this either.
If it had been a mammal, I would have guessed that it was a chimera,
resulting when two zygotes merge into a single organism.
https://en.wikipedia.org/wiki/Chimera_(genetics)
--
Christian "naddy" Weisgerber ***@mips.inka.de
Dorothy J Heydt
2021-02-28 17:27:46 UTC
Permalink
Post by Christian Weisgerber
Post by Quadibloc
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.
I certainly never heard of this either.
If it had been a mammal, I would have guessed that it was a chimera,
resulting when two zygotes merge into a single organism.
https://en.wikipedia.org/wiki/Chimera_(genetics)
The best example of a chimera in ordinary life is the calico cat.
Or the tortoishell cat, but the calico is a lot more common.
Genes for fur color are carried on the X chromosome. Some of the
calico's cells are coded for black fur, others for orange.
There's also a gene for no color, that is, white. The tortie
lacks this one, so she's just black and orange. Note that both
kinds are *always* female, having two X chromosomes. The only
way you could get a male calico or tortie would be if he were an
XXY male, and he'd be sterile.
--
Dorothy J. Heydt
Vallejo, California
djheydt at gmail dot com
Www.kithrup.com/~djheydt/
Jibini Kula Tumbili Kujisalimisha
2021-03-01 17:37:05 UTC
Permalink
Post by Christian Weisgerber
Post by Quadibloc
These pictures look like something out of Star Trek. I was not
aware that there were creatures in the world that were
literally female on the left side and male on the right side.
I certainly never heard of this either.
If it had been a mammal, I would have guessed that it was a
chimera, resulting when two zygotes merge into a single
organism. https://en.wikipedia.org/wiki/Chimera_(genetics)
The thought had occured to me, as well.
--
Terry Austin

Proof that Alan Baker is a liar and a fool, and even stupider than
Lynn:
https://www.cbp.gov/newsroom/stats/sw-border-migration
(May 2019 total for people arrested for entering the United States
illegally is over 132,000 for just the southwest border.)

Vacation photos from Iceland:
https://plus.google.com/u/0/collection/QaXQkB
Robert Carnegie
2021-02-28 20:19:29 UTC
Permalink
These pictures look like something out of Star Trek. I was not aware
that there were creatures in the world that were literally female on
the left side and male on the right side.
<https://www.snopes.com/fact-check/photo-dual-gender-cardinal/>
I wrote a reply that seems to be lost.

To sum up: they haven't examined this critter
closely. It may have no male or female fertility.
Human hermaphrodites mostly don't, or sometimes
have one, not the other. And we use the same
proto-gonads (which I may have invented) to be
one or the other. I don't know if that goes for birds.

Human sexual chimerism, not necessarily the
same thing, may be less visible because we don't
distinguish male and female by colour of plumage.
Only by where some of it grows. And other things...

ObSF: Dr Conway in James White's _Star Surgeon_
tells Dr Murchison at the beach (they are on a space
station but there's a beach) that his, Conway's, chest
is naturally not hairy. I expect hers also is, but we
don't find out in this story.
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