Originally Posted by Seattle_Aquarist
Hi @Blue Ridge Reef
How about this:
bb = dark ram (two recessive genes)
bB or Bb = light ram with dark gene
BB= light ram
In theory 3/4 would be light colored and 1/4 would be dark colored.
That works, assuming the hets are visual dark rams. Which does happen with a few things. But if you lay this out as you drew up, the dark rams would both be bb which would only produce dark fry. I'm thinking this must be a matter of visual hets. Or something more complex entirely.
That sounds about right when dealing with heterozygous traits. Two animals that are “100% het” would produce about 20-25% of their offspring in that particular color morph.
This is probably accurate -what makes it unusual is that hets aren't generally visual for the trait they are heterozygous for. I'm of the mind that these must be one of those exceptions in which the het animals are actually visual. In corn snakes, we had this with tessera, a striped corn mutation. It was at first believed to be a co-dominant gene, but after some breeding trials we realized that the Bb version of this gene looked just like the bb version. You couldn't tell them apart unless bred back to a normal. If 100% were striped, the animal was considered a "super tessera," and if 50% did, it was a regular tessera. But for love or money you couldn't distinguish the two apart. Wonder if dark rams aren't either a 2 gene combination or something a little more complex than just one recessive gene. I can't think of a scenario in which two animals showing the same recessive gene only make 25% of offspring showing it.