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Comments: 117 + - Science: Half-Male, Half-Female Fowl Explain Birds' Sex Determination on Thursday March 11, @04:48PM
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Kanan excerpts from a BBC report out of Scotland: "A study of sexually scrambled chickens suggests that sex in birds is determined in a radically different way from that in mammals. Researchers studied three chickens that appeared to be literally half-male and half-female, and found that nearly every cell in their bodies — from wattle to toe — has an inherent sex identity. This cell-by-cell sex orientation contrasts sharply with the situation in mammals, in which organism-wide sex identity is established through hormones."
Kanan also supplies this link to some pictures of the mixed-cell birds.
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Interesting (Score:4, Funny)
So would one of these hermaphrodite chickens be called a half-cock?
I agree with the section "Clucking confusing."
Re:Interesting (Score:4, Funny)
Parent
Re: (Score:3, Funny)
If two sexually scrambled chickens get together, will one lay scrambled eggs?
Re:Interesting (Score:4, Funny)
Since this seems to be the "joke" thread, allow me to put in my $0.02
I was on a farm doing research on genetic engineering and kept seeing something zip around at amazing speeds. I asked the farmer what it was and he told me it was chickens.
"See," he said, "the drumstick is everyone's favorite part of the chicken. So we engineered chickens with three legs. For every two chickens we sell, it's like we are selling three, leg-wise. It actually reduces waste since the factories don't find themselves with extra breasts and other crappy parts that they have to throw away or turn into chicken nuggets."
I said, "WOW!!!! That's amazing. How do they taste?"
He replied, "Hell if I know. We haven't been able to catch one yet!"
________________________________________________________
Please, tip your waitress.
Parent
Re: (Score:3, Interesting)
Also, when a flock of chickens suddenly loses it's rooster, the dominant female will sometimes act as a rooster. That isn't hormonal?
This does happen.
Apparently this is not all that common, that is, not every hen can become a henry, and perhaps TFA suggests the means by which this does happen when it does.
Apparently One in 10,000 hens can change sex [answers.com], usually in response to a gonad ceasing to function. One professor explained it this way: [angelfire.com]
"Yes a type of sex reversal does occur in poultry. Both a right and left ovary start to develop in the embryo but between day 7 and 9 of incubation the right gonad ceases to continue development.
Re: (Score:3, Informative)
Re: (Score:2, Insightful)
Sex (noun) and gender are two distinct things.
Well, no. Sex and gender identification are two different things.
Have you ever noticed that in same-sex pairings, it is common for one member to act very masculine, and the other act very feminine, regardless of what the pair's actual sex is?
Sometimes, yes, sometimes no. What you are speaking about is quite irrelevant to the discussion and has less to do with gender identification than emotional roles in relationships, which is an entirely different thing.
Re: (Score:2)
About one in every 10,000 chickens is gynandromorp (Score:5, Interesting)
That's somewhat close to the rate of intersex conditions in mammals, including humans.
Dinosaur extinction (Score:4, Funny)
Are you suggesting that the Gay Agenda was what wiped out the dinosaurs?
I suspect the real events that affected their reproduction involved Mass Quantities of Death, and the difficulty in getting Zombie Dinosaurs to reproduce.
Parent
gynandromorphs? (Score:2, Redundant)
Object-sex-oriented? (Score:5, Funny)
Whereas mammals have a global static variable where SEXUAL_ORIENTATION = MALE or FEMALE.
This is interesting because I thought we all inherited from a common ancestor. Was sexual orientation not defined in the root class?
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Re: (Score:3, Insightful)
No, the common ancestor of all animals almost certainly reproduced asexually (as do many primitive animals today), so it would not be defined by the root class. There are of course more recent common ancestors between birds and mammals, but XY seems unique to mammals.
See ZW sex-determination system [wikipedia.org] and X0 sex-determination system [slashdot.org].
Re: (Score:2)
First, your link to the explanation of the X0 system is broken.
Second, I don't know for certain, but I think that the sex determination function is handled like Common Lisp inheritance (inherited from an instance, not an abstraction like a class definition, especially of a root class) rather than C++, Java, C#, etc. Evidently, said function was replaced in the mammalian line, just as color vision was (birds and reptiles have four primary colors, most mammals have only two, and pro-simians and primates have
Re: (Score:3, Interesting)
that was meant to be a wikipedia link, something weird happened when I did a preview, edited again, and submitted (I had missed a closing quote before the first preview, but I think that caused slashdot to munge the URL, but I was going quickly). In any case you can search on that in wikipedia.
My point is there are lots of ways to do sex determination. Echidnas and Platypuses are particular weird in this way (and in every other way), even though they are mammal they don't use XY.
And of course, in the most
Re:Object-sex-oriented? (Score:5, Funny)
In both cases, each cell has its own this.getGender() function.
In both cases, I would imagine the code looks something like this:
class cell {
int gender;
proteinFactoryBuilder asdf;
getGender() { /* I don't really have time to go back and fix this right now, but if I'd known I'd be making multicellular organisms with this shit I wouldn't have put this at the cellular level. Anyway, we're stuck with it, so for now I'm just returning the gender variable and I'll leave it to callers to figure out wtf to do with unexpected output. */
return gender;
}
}
Small wonder it's a little more confusing for birds.
Parent
Re: (Score:2)
I'd imagine there is no written code involved in today's organisms. However, the very first cell had this:
int survival_chance_of_mutation = rand(); // who cares, it'll crash anyway
Re: (Score:3, Informative)
Re:Object-sex-oriented? (Score:5, Informative)
This might go a long way towards explaining gynandromorphism in birds. In mammals, maleness is handled in a top-down fashion- the Y chromosome does not explicitly specify most aspects of the male phenotype, instead simply encouraging the cells that go on to make androgens, which then go on to produce a cascade of developmental effects throughout the body. In birds, the Z and W chromosomes both may have enough genes that sex determination can be handled from the bottom up, locally in each cell.
Parent
Re: (Score:3, Insightful)
...unlike the mammalian Y chromosome which has been paring down its genes so that it contains the sex-determining gene SRY, some genes necessary for sperm production, and little else. ...This might go a long way towards explaining gynandromorphism in birds. In mammals, maleness is handled in a top-down fashion- the Y chromosome does not explicitly specify most aspects of the male phenotype, instead simply encouraging the cells that go on to make androgens, which then go on to produce a cascade of developmental effects throughout the body.
Even so, with the XY chromosome - cutting off body parts and taking hormones does not make a man a "woman" any more than flapping one's arms makes one a bird. Mammals sex inheritance isn't as neutered as the interpretation of the article suggests - only that fowls goes a bit deeper into it than mammals.
Re:Object-sex-oriented? (Score:4, Funny)
Parent
Re: (Score:2)
From what I gathered, in mammals it's more like all the cells are Observers and what they're observing are hormonal signals that indicate sex.
And as someone else observed, this is about sex, not gender identity or sexual orientation. This will get messy in a hurry.
Re: (Score:2)
Apparently. Sex has to be specified in each single object through a getter/setter method.
But the root class has only one private method. All we know is if we inherit the class we're alive.
Re: (Score:3, Funny)
So each cell has it's own this.getSexualOrientation() function.
That’s Java right? Then, wouldn’t that be this.getFactoryFactory().getOrientationDeterminationFactory(this.getFactoryFactory().OrientationDeterminator.SEXUAL).getSexualOrientationDeterminator().execute()?
Re:Object-sex-oriented? (Score:5, Insightful)
Sex is what you have between your legs.
Gender identity is what you want between you legs.
Sexual orientation is what you want between someone elses legs.
Parent
Re:Object-sex-oriented? (Score:5, Funny)
Don't be silly.
Sex is what you want but can never get enough of.
Gender identity is what lets you pick out cross-dressers and transvestites.
Sexual orientation is how you're oriented during sex, i.e. missionary, doggy style, reverse cowgirl, Saskatchewan Swinging Simian power retrograde style, etc.
Parent
Re: (Score:3, Insightful)
Sexual intercourse is what you have been genetically programmed to do with what you have between your legs.
n00bs (Score:5, Funny)
They're not the first ones to be checking out a nice-lookin' bird and then see from another angle that "she" is really a man.
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Re: (Score:2)
But don’t you know about the bird?
Because everybody knows about the bird.
Ba-ba-ba baa-baa-ba baba-baba ba, baba-baba-ba baba-baba-ba,
ba-ba-ba baa-baa-ba baba-baba ba, baba-baba-ba baba-baba-ba,
don’t. you. know. about. the. biiird?
Everybody knows about the biird...
Ba-ba-ba baa-baa-ba baba-baba ba, baba-baba-ba baba-baba-ba,
ba-ba-ba baa-baa-ba baba-baba ba, baba-baba-ba baba-baba-ba,
Ba-ba-ba baa-baa-ba baba-baba ba, baba-baba-ba baba-baba-ba,
ba-ba-ba baa-baa-ba baba-baba ba, baba-baba-ba baba-baba
Lends more to the old paradox chicken or the egg (Score:2)
Now you'll have a fresh material to argue which came first...
How to Sex Chicks (Score:2)
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silly (Score:3, Informative)
Re: (Score:3, Interesting)
Birds on the other hand use Z/W chromosomes for sex determination, as do most fish, some insects and some reptiles. So the big eyed "Ooooh, who would've thunk that birds aren't handling it the way we mammals do?" attitude of the article seems kind of silly considering we've known about this striking difference for a long time.
Okay, but knowing that the nature of the sex chromosomes is different isn't the same as knowing that the overall mechanism by which the sex of the organisms is determined is different.
Re: (Score:3, Insightful)
why should we assume that the implementation on the organism level would be identical? Isn't it more intuitive that there would be differences? But finding the "unexpected" makes for a better article than finding the expected...
Nobody ever thought they'd be identical, and of course there will be differences. That's not the same as expecting it to be completely opposite.
Expecting some kind of difference is not the same as expecting this difference. This difference was unexpected.
You can't say that because
Re: (Score:2)
In other words, given that we know that sexual differentiation is a phenomenon that has evolved at multiple times via multiple genetic mechanisms in multiple phyla, classes and orders why should we assume that the implementation on the organism level would be identical?
Do we know that it has occurred more than once (with the evolution of eukaryotes [wikipedia.org])? My impression was, despite the process of sexual differentiation being remarkably variable in its manifestation, there's no indication that it came about more than once.
Changing Sex (Score:2)
So I wonder if the applies to spices that can change sex at "will". I seem to recall that there are some fish, frogs and lizards that can do this.
Re: (Score:3, Informative)
No... I’m thinking those species would have sexes which were entirely hormone-driven.
That’s basically the exact opposite of the chickens, in which sexes apparently have very little to do with hormones, and are entirely based on the genetics of the cells.
Humans would be somewhere in between. A man will grow breasts if you give him enough hormones, but you’ll have to do something surgically to change the penis...
Re: (Score:2)
Humans would be somewhere in between. A man will grow breasts if you give him enough hormones, but you'll have to do something surgically to change the penis...
My gf showed me pictures in her biology text of what were genetically men who appeared externally to be completely female, including with vaginas. Internally they lacked a uterus.
Hurray! (Score:3, Funny)
Now we can produce twice as many chicken breasts.
I suppose we’d better not be going off half-cocked, though. More grant money!
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Re: (Score:2)
I'd be more impressed if they found a confused half-chicken half-buffalo.
Oh great! (Score:2)
Another story about Al Gore.
Bi Bi Birdie (Score:2)
Any bird can teach you something about the birds and the bees, assuming of course, that you're not a bee.
Re: (Score:2)
I suppose I deserved to be subjected to bad puns just for opening this thread.
"Intersex Chickens" is just one of those topics one should avoid on Slashdot. What was I thinking? /me escapes before "chicks with..." jokes start.
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Re: (Score:3, Informative)
Seriously. What I'm inferring from the article is that you can see the difference in the cells, e.g. male vs. female....
Yeah you can see that their sex chromosomes are different.
So how the hell have they never noticed that female and male birds have these slightly different cells before, and reached the non-hormone driven conclusion before this?
Because to notice this you have to specifically study the birds who have cells that are mixed between male and female, and then notice that the sexual characteristic
Teenage Mutant Ninja Chickens (Score:2)
In Soviet Russia, the Overlords joke welcomes you....