Easter Egger chick parentage question

[Alia]

Rose comb should be dominant over single comb. If those are the stats, I doubt you will see a single comb unless the Australorp specifically breeds with an Easter Egger who is already carrying it. That said, in nature, darker coloured animals tend to be dominant over lighter coloured animals, weighting the babies toward the Autralorp. (Single combs actually make roosters more dominant, too, which is why I prefer non-single combs. Also they can hang in the poor chickens' faces. Also they're vulnerable to frostbite.)

Now what I have heard is that the blue-egg gene is separate from the brown-egg gene. It's its own thing. So you can have a chicken who is homozygous for both. (As has been said, lovely olive eggs there.) So if you've got Easter Eggers who carry two copies because the hatchery bred them as Easter Eggers, with other Easter Eggers, all their babies should get one copy, and have the potential to produce lovely Easter eggs. All the fathers seem to be brownies, so you'll get chickens who all lay eggs in various shades of green. Probably no blue.

 

[debid]

Rose comb should be dominant over single comb. If those are the stats, I doubt you will see a single comb unless the Australorp specifically breeds with an Easter Egger who is already carrying it. That said, in nature, darker coloured animals tend to be dominant over lighter coloured animals, weighting the babies toward the Autralorp. (Single combs actually make roosters more dominant, too, which is why I prefer non-single combs. Also they can hang in the poor chickens' faces. Also they're vulnerable to frostbite.)

Now what I have heard is that the blue-egg gene is separate from the brown-egg gene. It's its own thing. So you can have a chicken who is homozygous for both. (As has been said, lovely olive eggs there.) So if you've got Easter Eggers who carry two copies because the hatchery bred them as Easter Eggers, with other Easter Eggers, all their babies should get one copy, and have the potential to produce lovely Easter eggs. All the fathers seem to be brownies, so you'll get chickens who all lay eggs in various shades of green. Probably no blue.

Except that it isn't that simple. Shell color is a quantitative trait meaning more than simply two pairs of genes controlling it. I suspect that researchers will eventually decide comb type is also quantitative because there are clearly modifying genes involved beyond the basic two pairs determining type.

Check out this article:
http://www.extension.org/pages/6536...backyard-flocks:-an-introduction#.UzWERnIo4iE

 

[Alia]

I don't see anything in that article about shell colour. It's just the very basics of chicken genetics. (Though I admit I didn't know Barred Rocks had dark shanks underneath their barring gene.) I still say I'm right, and Easter Eggers' offspring should still produce easter-coloured eggs, whether they are green or just a little bit green. Everything I've read on the subject says that brown egg and blue egg are separate and a chicken having both will make green or olive eggs, and even that the blue tint of the egg is actually deposited in a different layer of the shell.

If it's just "not that simple" feel free to explain it. Genetics happens to be something I know a lot about and I'm always willing to learn more. What will the offspring of those crosses give? Blue eggs? Green eggs? Light green eggs? Why?

The basic fact about the combs is that there are two sets of genes controlling the comb, and if the chicken gets either of the dominant ones, it will make the comb not single. If there are modifying genes, then that's still true. Unless you're working with both sets of genes, it's easier to think of non-single combs as rose combs, which will be dominant over single combs. I think of them this way simply because I find it difficult to tell comb-type by looking. When I was young I had a book with that very same comb illustration in it, and I could not match any of my chickens' combs to the kinds they were supposed to have by breed and the illustrations in the book (except single combs of course).