Like the title says im wondering what causes degeneration to create bad genes. I had a cockatrice a long while ago (now in reserve) who got one degeneration and half his genes turned bad. But my seeker line has some symurghs who have one degeneration and not one bad gene even in recessive.

From what I can tell, it's a percentage chance that each gene they receive is mutated to a 'red' one, so even at one degen, the beast can have a full roster of said 'red' genes. You probably just got un/lucky with the pets