The term I am using is the evolution of lines. Is a sire’s name in pedigree present due his potency for generations or that the combination the bitch line made a better overall offspring such as River Oaks Corky? As I study these pedigrees of years ago I see certain lines are always present while other lines are like a candle with the light flickering then burning out. When we get a strong contender the number of breeding combinations for the popular sire gives more opportunity to be a wider spectrum of bitch’s good to mediocre.
These wide spectrum of breedings is akin to the corn breeder testing the combining ability for their lines. In the case of Corky’s dam a daughter of Grangemead Precocious, Shed of Arden son. I have concluded that these dogs area still in pedigrees today because of the breeding philosophy of breeding good by good. The next generation offspring ranging in quality getting the right stuff.
The right stuff for polygenic traits might be like mixing a bag of coins and then dumping them out then count the “heads”. The heads would be the desired alleles and the more the better the dog. So the new super dog is bred and the parents are listed in the pedigree. Some of the bitch’s listed in pedigrees like little Peggy Black Gum, daughter of Marvadel Black Gum, who’s son was Yankee Clipper of Reo Raj.
So are these lines carried along because they add to subsequent generations, or because they produced a good dog?