I certainly have seen mixed-color earlobes on hens, so earlobe color is at least partly controlled by something that is not on the Z chromosome.I wonder if this points toward involvement of the Z chromosome, with males requiring two copies for a full presentation.
I've read that some skin color genes, such as id+, are on the Z chromosome.
@NatJ
@nicalandia
@DarJones
What do you guys think?
Beyond that, I don't know.