Quote: I get what you are saying . . . . Most features in a bird or any animal is the result of many genes in effect.
In addition genes are located on strands of chromosomes and it is the whole chomosome that is replicated and divided, so it usually stays together as one strand BUToccassionally a cross over happens and genes can get swapped. THe genes for skull width a nd body width are on the same chromozome-- either one very strong over powering gene, or several modifying genes. THe old timers already knew the correlation.
That is why observation and mentors was and is a great learning tool.
Leg bone still has me stumped-- I know how it works in horses. but in chickens the bone is a different type-- the hollow bone so that is a big factor.
I'm at the beginning of chickendom and don't have a mentor at this point but I know basic genetic selection and how to selection and culling works, especially in horses, but need to devise a process for chickens that I can work with year over year.