The Legbar Thread!

[GaryDean26]

A sea turtle isn't a chicken. Yes, they also have proved that the gender is determined 100% by the incubation temperature in alligators, but again a gator isn't a chicken either. Things work differently in Turtles and Gators. Their chromosomes don't specify a gender. The incubation temperature triggers how much estrogen and testosterone is produced in the embryo which governs gender.

Remember Jurassic Park where they used Sea Turtle Eggs to clone dinosaurs and the female dinosaur turned into males and started breeding (like Sea Turtles apparently are capable of due to the lack of gender specification in the chromosomes)?

If chickens gender worked the same way as Sea Turtles I guess our laying flocks that don't have cockerels would have hens spontaneously turning to cockerels so they could reproduce. Thank goodness birds are more complex genetically than reptiles.

 

[cjwaldon]

This happens in some fish, too. Where no males are present, a female will change gender and the species goes on.

 

[CibolaChooks]

Yep! In chickens the gender is determined by the hen and is set at the time the egg is laid.

In the case of the 18 eggs that produced 7 cockerels and 1 pullet there may have been 9 eggs that would have produced pullets and 9 eggs that would have produced cockerels, but the conditions such that male embryos were better suited for survival to hatch.

I have heard of some people that wanted to hatch fertile eggs sold for consumption that had been refrigerated. They were advised that they could do so, but the hatch rate would likely be low and probably result in a lot of cockerels because the male embryos were "stronger". I don't know if anyone ever did any test hatches to prove this though. It is probably just a theory, but along the same lines as the humidy theory.

i can see that. Environment being a factor in which of the embryos hatch better due to cockerels embryos possibly being stronger. Soooo, if In fact that's the case... If were were able to pin point these factors that make female embryos hatch better, we will still always probably end up somewhere around half and half pullet to roo. Like the lady with 7 to 1 out of 18 eggs. if these factors exist and she manipulated the environment to help the pullet embryos pull threw she could have got more pullets or somewhere close to even numbers in the eggs that didn't hatch. So this is just another which came first topic< RIGHT. We might not ever find the correct answers. .

 

[GaryDean26]

reptiles too now that i think about it. haha. maybe I'm all wrong. we might still be able to find chickens life factors that might help persuade a wanted sex. maybe its just mammal's that are random... Its weird that there is allot species belonging to the sea have other factors determining gender.

I know people that "Stress" their herd sires in cattle and goats to produce more females than males. In mammals the male determines the gender (opposite of birds). They say that the male chromosomes travel faster than the female chromosomes but that they don't live as long. They claim that an "unstressed" herd sire will produce more male off because the males chromosomes reach the egg before the females chromosomes can, but a "stressed" herd sire will have the more female off spring because the fragile males male chromosomes die before they reach the eggs allowing more female chromosomes to fertilize the eggs (tortoise and the hare theory is guess).

Again, I don't know how much of this has been extensively studied or "proven", but a goat breeder a few hours from me said she has got more does than buck since she started stressing her sires four years ago.

 

[lawatt]

A sea turtle isn't a chicken. Yes, they also have proved that the gender is determined 100% by the incubation temperature in alligators, but again a gator isn't a chicken either. Things work differently in Turtles and Gators. Their chromosomes don't specify a gender. The incubation temperature triggers how much estrogen and testosterone is produced in the embryo which governs gender.

Remember Jurassic Park where they used Sea Turtle Eggs to clone dinosaurs and the female dinosaur turned into males and started breeding (like Sea Turtles apparently are capable of due to the lack of gender specification in the chromosomes)?

If chickens gender worked the same way as Sea Turtles I guess our laying flocks that don't have cockerels would have hens spontaneously turning to cockerels so they could reproduce. Thank goodness birds are more complex genetically than reptiles.

I did not mean to suggest that turtle/reptile gendering worked anything like *chickens* -- i was responding to the post that said fish were the only kinds of organisms where gender was affected by external conditions.

and bird genetics isn't necessarily more complex than reptiles, it's just different -- and somewhat related, since birds evolved from reptiles. but definitely not the same, and that's not what i meant to say.

(my dad's an evolutionary geneticist, so the topic is of some interest to me!)

edit: and sea turtles can't just "change" gender once they've hatched -- it's determined by the temperature of the nest while they are developing in the egg.

 

[Phage]

Nice picture!

sheesh--- I wish we had your grass! :O)

Yea, that grass makes me feel homesick.
Johnn, where in the UK do you live?

 

[GaryDean26]

I did not mean to suggest that turtle/reptile gendering worked anything like *chickens* -- i was responding to the post that said fish were the only kinds of organisms where gender was affected by external conditions.

and bird genetics isn't necessarily more complex than reptiles, it's just different -- and somewhat related, since birds evolved from reptiles. but definitely not the same, and that's not what i meant to say.

(my dad's an evolutionary geneticist, so the topic is of some interest to me!)

edit: and sea turtles can't just "change" gender once they've hatched -- it's determined by the temperature of the nest while they are developing in the egg.

Got it. I didn't see the fish post.

P.S. I took a math class in college titled "Basic Complex Analysis". I know it sounds like an oxymoron, but the word complex has a lot of different meanings.
I didn't mean that reptiles genetics are easier than birds, just that they are lower on the scale of fish-->amphibian-->reptile-->bird-->mammals and yes different.

 

[Johnn]

Yea, that grass makes me feel homesick.
Johnn, where in the UK do you live?

in cumbria

 

[Phage]

Quote: That is funny!
I would have said Lake District

. Guess it was that sort of typical weather hardy grass and rolling hills

 

[Johnn]

That is funny!
I would have said Lake District

. Guess it was that sort of typical weather hardy grass and rolling hills

haha!