My Science Teacher said something I do not particularly agree with....

[Henrietta23]

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I've read back through it all a few times now. There's a lot there. It was all something I'd never given any real thought to before.
(Dutifully taking the hint and returning to the actual subject....)

 

[SunChick]

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WHOA! you have never been to my college. www.fit.edu. You want science background, we got it, you want to add math to that...got that too! I had to take Calculus I and II to graduate. Check out our program; we are now required to do our own research...and I did (I was the guinea pig!) I was pre-veterinary before transferring to education (and only because I got married had a kid and moved too far from a veterinary college). I think we have even produced a teacher of the year....

I think my college is an exception to the rule! Go Florida Institute of Technology!

 

[FutureChickenMan]

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The chicks are injesting the dye from the yolk. There is no genetic change taking place. This would not work as well on darker chicks as the pigment in their down will hide the color of the dye. It's a by-product of diet. And yellow chicks are not yellow because the yolk is yellow. Mr teacher is confusing his facts. And as soon as the chicks feather out, the dye is gone.

 

[barg]

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Again, the statement made by the teacher, taken at face value, is accurate, if not complete.
Some Chicks Are yellow because they eat the yolk which contains pigments that are used in the skin, shanks etc...
Since the exact meaning of the teacher is not known, we can not say that he was wrong; His statement is true.


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Geneteic change does not appear to be in dispute here and no mention of it was made.


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Based on available information, this can not be proven nor disproven.
Since we know the teachers statement to be accurate, We would need to know the exact context of his statement in order to make a determaination on his state of confusion.

Once again, there are several sources that can confirm that the teachers statement is accurate this is one of them
And though this site is not held in the highest regard, it does provide another source of information

 

[FutureChickenMan]

"Again, the statement made by the teacher, taken at face value, is accurate, if not complete"

Disagree, if taken at at face value that yellow yolk = yellow chick, than chicks that are striped, red, grey, black would have to have striped, red, grey, black yolks respectively. Stating that a chick is yellow because the yolk is yellow is an absolute. Which can easily be proven errant as all the afore mentioned colored chicks all were fed from yellow yolks. Their color is determined by the genetic information stored in their DNA passed from the parents. When you dye the yolk you are causeing the fluff to change color as a by product of their digestive system. Just like if you ate a bunch of garlic today, you'd smell like garlic tomorrow. It's a waste by product from consumption. But to state that the chick is yellow because the yolk is yellow without further clarification of meaning is in my opinion misleading. Chicks are yellow because their dna says, be yellow. When you dye the yolk, you're introducing a result that is not normal, based on diet. Just as yolk colors vary based on what the hen ate when developing the ovum.

If you are meaning that all yellow chicks came from yellow yolks that would be true; just as all chicks come from yellow yolks (unless tampered with) is true. That's when being there counts and knowing the intent of the speaker.

 

[ivan3]

That's when being there counts and knowing the intent of the speaker.

True enough. But that it tickled Dinos_Rock's BS detector sufficiently to post here, thereby allowing us all to weigh in and maybe learn something more ourselves, is sufficient reason for me to not only applaud Dinos_Rock's
perspicacity, but to tip the hat to the source of the statement (I used to pray for teachers that reached a little too far on far too little - I learned to reach a little further without stepping over the edge because of them). This seems to be what Dinos_Rock was doing by searching out info/advice by posting.

Barg, it's a shame R.D. Crawford's entire book isn't online (seems it might be difficult to get in print). If the complete bibliography was listed it probably includes this gem: Chickens fed pork livers and paper pulp to produce colorless yolks - along with a description of their offspring:

http://www.pnas.org/cgi/reprint/5/12/582.pdf

And, to delve into the little lower layer (speaking of genetics) of far more recent research regarding the hunt for the precise locations and mechanisms involved:

http://www.pubmedcentral.nih.gov/articlerender.fcgi?&pubmedid=15579702

This has been an interesting thread. Thanks, Dinos_Rock!​

 

[barg]

Wow! I'm not even sure where to begin, your entire rebutle makes so many assumptions, its hard to decide which one to tackle first.
I am hopeing that you read my previous posts on the matter, it does seems as though much of the information within that was completly discarded without being addressed.

I guess I will start from the begining

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Uhm, yeah…. As mentioned before, egg yolk contains Xanthophyll which is what makes it yellow, the Xanthophyll is passed on to chicks giving their skin shanks etc a yellow color, a color that they can not make on their own and must get from the food they eat.
I have already sited a couple sources to back this statement up.

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The data does not back up this claim. Just because one chick becomes yellow from eating a substance, does not mean that all chicks will be yellow…
However, making a statement that “the reason chicks are yellow, is because the yolk is yellow” does not exclude chicks that are not yellow from remaining that way, even if they do consume the same food; an attempt to make this mutually exclusive is an invalid argument. Again I have sited sources that explain this further in my previous posts.

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As stated before, not all coloration is a result of pigments created by an organism, many pigments are acquired through diet; again, I have already sited sources to back this statement up.


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Misleading yes, but not inaccurate. As I stated previously, “the statement made by the teacher, taken at face value, is accurate, if not complete” and “We would need to know the exact context of his statement in order to make a determination on his state of confusion.”

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Again, if you read the sources I sited previously you would have learned that chickens derive their yellow color from their diet and do not produce the compounds used for the yellow pigmentation.
Therefore, it is true that a chicken must have the right set of genes for the yellow pigment of their food to have a visual effect on their coloration; it is not true that the genes passed on from their parents direct them to produce a substance that causes any yellow pigmentation.

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Now you’re getting it! The amount of Xanthophyll present in the food that the hen eats will determine the amount of yellow pigmentation within the yolk of the egg. Ultimately the pigmentation of the egg will be consumed by the chick which will alter the chick’s pigmentation.

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I would counter by saying, knowing the context of the speaker is important in that, we need to know if he is making the statement that chick down is effected by the pigmentation contained in the yolk, or did he mean that the chicks skin, shanks, fat, beak are affected by this; the latter being correct while the former being incorrect.

I took each point made in the original post and found information that was valid to each point, with the intent to discover the truth about the statement.
I separated ideas that were not specifically dependent on each other.
I have sited sources that back up any statements I have made, and have tried not to make any assumptions about things for which information was not provided.
I do enjoy a good debate, and as, this is a topic for which most of my experience is all of about 48 hours, I welcome any valid rebuttal.
Please site your sources

 

[dlhunicorn]

On YOLK color:
http://www.georgiaeggs.org/pages/color.html
".... Yolk color depends on the diet of the hen. If she gets plenty of yellow-orange plant pigments known as xanthophylls, they will be deposited in the yolk. Hens fed mashes containing yellow corn and alfalfa meal lay eggs with medium yellow yolks, while those eating wheat or barley yield lighter-colored yolks. A colorless diet, such as white cornmeal, produces almost colorless yolks. Natural yellow-orange substances such as marigold petals may be added to light-colored feeds to enhance yolk color. Artificial color additives are not permitted. Gold or lemon-colored yolks are preferred by most buyers in this country. Yolk pigments are relatively stable and are not lost or changed in cooking..."

http://www.msstate.edu/dept/poultry/extcull.htm
".....As the hen produces eggs, she diverts yellow color from certain portions of her body and deposits it into the yolks of the eggs. Bleaching of various parts of the hen's body is a very good indicator of the time the hen has been in production. The loss of color is easily seen in yellow-skinned breeds such as the white leghorns and birds on diets containing sources of the coloring agents. In the white-skinned breeds the bleaching effect is less pronounced and more difficult to detect...."

....of course genetics play a role (and the articles for "dying" chicks do say to use a "white colored " breed...): and when speaking of these white colored breeds:
http://www.encyclopedia.com/doc/1P1-33259479.html
"....Rebecca Jones; News Staff Writer
Denver Rocky Mountain News
10-08-2000
EGG YOLK DIET GIVES CHICKS YELLOW DOWN
Why are baby chickens and ducks born yellow? We know they turn white later as they get older but never understood why they're yellow at birth. - Sharon and Carl Valentine
What color is an egg yolk? If you said ``about the same color as a newborn chick or duckling,'' you've been carefully studying your egg yolks. That yellow coloring comes from xanthophyll, the pigment in the yolk ....."

...back to the teachers statement:
The "coloring" of the chicks only affects the down feathering and down feathering (and how an injected pigment/dye affects it) is the only thing that can be relevant here since if I remember correctly the teacher was specifically referring to these (artificially created) colored chicks and how they were achieved.

 

[barg]

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In the original post, the two ideas are sperate and distinct, at least in the way it is written within the post.
I made no assumption that the two ideas were intended to be cause and effect.
If the statement would have read "Anyways, my teacher said that the reason chicks are yellow, is because the yolk is yellow.and as a result of this if scientist injects dye with a needle into the yolk, the chicks hatch out different colors.
In the new version a connection is made that implies that the two instances of coloration are a result of the same process, in the original version, the two ideas are clearly seperated with the words "and that".
Example: "my teacher said that he has a gold fish and that he has 20 dollars in his wallet"
Or
"My teacher said that he has a gold fish and as a result of this he has 20 dollars in his pocket"
In the second instance a more clear connection between the goldfish and the 20 dollars is established, while in the first instance the two ideas do not seems to have a nessiasary connection.

You see, it really all depends on what your definition of the word "it" is.... sorry I couldn't resist.

ivan3 , nice post that seems to further confirm my statements

Thanks

 

[ivan3]

What is the predominant yolk color of eggs of the Class Aves? And is there a common color among day old chicks of the class?

I can kinda see (if I stand on my tiptoes) what the teacher meant to say. But by saying the chicks are yellow because the yolk is yellow (and this should hold true for all birds with yellow yolked eggs), strikes me as just a bit off (`had a certain syrup but it doesn't pour').

Please keep posting the links, this is excellent!