Yes, from what I've read, it seems likely that "Peach" occurred as a crossover in a male split to Purple and Cameo. What then happened is that instead of having one Z chromosome with Purple and one Z chromosome with Cameo, that male (or his sperm, depending on if the crossover happened during his embryonic development or during his sperm production) gives one Z chromosome with Purple AND Cameo and the other with neither. That's the only way the IB hen, sister to the first "Peach" hen, could have been produced from a Dad split to Purple and Cameo.
If you had a "Peach" male, that means that he has Purple and Cameo on both of his Z chromosomes, so all his hen offspring would be "Peach." However, if my hypothesis is correct, if a "Peach" male was bred to a Purple female, all his sons would be Purple, because they'd get one Z chromosome from Dad with "Peach" (which would really have Purple and Cameo on it) and one Z chromosome from Mom with Purple on it. Thus the males would have two Z chromosomes -- one with Purple on it from Mom, and one with Purple AND Cameo on it from Dad. In males, two copies of Purple makes Purple, but only one copy of Cameo isn't enough to make Cameo. All the hens would be "Peach" because their one Z chromosome, from Dad, would have Purple AND Cameo on it. We have to remember that birds don't inherit just one gene in isolation -- they get the whole chromosome that the gene sits within. So if "Peach" really is a combination of Purple and Cameo, we can't get one without the other unless another crossover occurs in a male split to Peach, and the two genes separate once again onto different chromosomes.
Oh, and if "Peach" really is a completely new mutation, and not a combination of Purple and Cameo, then breeding a "Peach" male to a Purple female could NOT result in a Purple male offspring. That one test breeding would confirm or deny my hypothesis. You could substitute Cameo, by breeding a "Peach" male to a Cameo female. In this case, if there are no Cameo males produced, "Peach" is truly a separate mutation and not a combination (but at this point, from what I've read, "Peach" is most likely a combination). But I'd think that, based on other posts, it'd be much easier distinguishing Purple chicks from "Peach" chicks than distinguishing Cameo chicks from "Peach" chicks.
The other mutations do not occur on the Z chromosome, so they'd be much easier to combine with the sex-linked colors because they won't require crossover. I don't know on which chromosomes the other mutations occur, and it's possible that two non sex-linked mutations might be found on the same chromosome (so, for example, if Midnight and Bronze were on the same chromosome, it'd be harder to combine them because another crossover event would have to occur, and these events are random). But by the nature of their inheritance, we KNOW that Midnight, Bronze, Charcoal, Opal, Taupe, Jade, and possibly Sonja's Violete (I don't know the last one for sure) occur on chromosome(s) different from the ones carrying Purple, Cameo and "Peach." So combining any one from the first group with any one from the second group would be just as easy as combining black shoulder with any one of the second group, as black shoulder is also an autosomal recessive mutation. The fact that the mutation is a color or a pattern has no bearing on figuring out how to combine them -- only the mode of inheritance.
I would also like to thank you tremendously for pointing out something that should have been obvious to me but wasn't. Yes, the reason I don't seem to get much information about this from breeders might be that they want to keep the origins of color-breeding in the dark, so that instead of allowing amateurs to mix and match on their own, the amateurs will have to wait until the big breeders make something new and buy it from them. I can't say for sure this is the case -- another member PM'ed me saying that 1) not all breeders are as well-versed in genetics, and 2) there seems to be a UPA-sanctioned "frowning" upon combinations of colors, but allowing combinations of patterns. Well, I guess if this goes unanswered for the years before I'm able to have my own peafowl, I'll just have to set up some breeding pens of my own and post the results for all to see. In the meantime, if anyone with peafowl is interested in some experimental breeding, I'd be happy to communicate what I know of genetics with your experiences, and perhaps guide you to creating a new phenotype resulting from combining two colors. I'd REALLY love to see what the darkening of Midnight looks like with Purple, especially since these two colors retain the iridescence of the original IB.
Thanks again, Deerman. I'm new to BYC, so I've only just been finding out that you're battling some health issues. Good health to you, and I hope you find some time and strength to continue enjoying your passions.
~Christopher
