So did a bunch of research on Porter's Family Tree as to names and colors
Father SBR Winston = Imperial (so Winston had 2 imperial genes, Porter had to get one imperial gene from his father and he got a grey gene from his mother, since Porter has a grey nose) out of an imperial and an imperial trim (Winston did not get the one royal gene from his parent that creates a trim, or he would have been a trim himself. Winston could only pass a solid gene to Porter) the imperial was out of 2 natives and ends there the Imperial trim was out of a Royal and a dead end. The royal out of 2 royals and then dead end
Mother TAYL Pepper = native out of an native and a native trim the native's dam was a native then all the lines die. (Porter's mother only has native genes to pass on. If she had gotten the possible royal gene in the trim parent, she would have been trim herself.)
Porter is a native but must have trim and royal and imperial gene's hiding some where There are 3 recorded calves of his. 2 bulls and a heifer all native BUT ALL their mothers were native as well. (Porter can't have a royal gene or he would be a trim. Porter definitely has one imperial gene from his father.)
Hola! Sorry if someone already responded. I'm still catching up.
So Porter cannot have a gene for trim/royal. If he had a royal gene, it would be expressed by him having white trim. There really is no trim gene; it is expressed when the animal has one royal gene and one native gene. If a yak has 2 royal genes, it will have the "pinto" pattern and be royal colored. If it has 2 native genes, it will be solid colored (Porter). Trim is produced when the animal gets one of each gene (solid & royal). These genes have "incomplete dominance" meaning each gene has some influence on how the yak looks. The genes kind of meet in the middle and you get a little of the royal and a little of the solid, which comes out trim.
So, given each yak has 2 genes, one from each parent, it's
Solid gene + Solid gene = Solid (native) animal
Winston, Pepper, & Porter
Solid gene + Royal gene = Trim animal
(several of your cows and calves)
Royal gene + Royal gene = Royal animal
You can tell what genes they have by how they look for native-trim-royal. Porter has no royal in him. All your trim calves got their royal gene from the mama.
The Imperial gene different and is inherited separately from solid/royal. (a gene is just a section of a chromosome at a particular location on the DNA strand). Like everything, each individual yak has 2 genes for this trait, one from each parent. This gene is expressed with either a grey or a black (imperial) nose, and has "complete dominance," where the grey is dominant over the imperial/black.
So there are two different genotypes possible for a yak with a grey nose
grey gene + grey gene = grey nose
(Pepper)
grey gene + imperial gene = grey nose (the imperial gene is hidden - not expressed- grey dominates)
(Porter)
Only one way to get a black nose
imperial gene + imperial gene = black nose
(Winston)
When you look at a yak with a grey nose, you don't know for sure whether or not it has an imperial gene. Only through breeding and seeing an offspring with a black nose, will you know. Two grey nosed animals can produce an imperial calf if each parent happens to have a "hidden" imperial gene and the calf is lucky enough to get that specific gene from each parent (25% chance). We know for sure Porter has one Imperial gene because he had to have gotten one from his father, who had two and had to have passed one to Porter.
Now I have to cook dinner. Catching up the rest of the way will have to wait.
