Importance of 3rd and 4th Gen - Page 1

I am reading Stephanitz' book and he emphasizes the importance of having good dogs in the 3rd and 4th generation (grandfather and great grand father). Its kind of unclear, but I think he is referring to line breeding 3-3, or 4-4.
How much importance do current breeders give to 3-3/4-4. How does that compare with eg importance of dam and sire ?. How far back do breeders look in line bred pedigrees.

What makes you think he is referring to line breeding ?

It would be important at the time, when the breed was founded by so few dogs, and a type was being established.

breeding dogs is not simple math.  many folks will argue inheritability by percentages only to be proven wrong.  certain dogs are more preponent than others.  certain characteristics are more inheritable than others.  certain locations on the pedigree will be more inheritable for a given charateristic.  most folks give entirely too much credit to the sire line.  in truth, there are only certain traits that a male can get thru his sire or his dam.  anyone who has been breeding dogs, or any animal, for a long time will tell you that it is not uncommon for certain traits to actually skip a generation and show up again in the grandkids.  this is why it is so important to know the dogs behind your breedings.....even to the 4th & 5th generations and especially so when linebreeding.
pjp

basically, if you have a "lucky" , a great dog from lesser parens, the chance that he will produce anything like himself are very small ,  but that goes for all outcross bred good dogs, there reproduction depends mainly on chance, and the amount and quality of the bitches bred.

There are two basic "types" of chromosomes.  1. Sex chromosomes (X and Y) and 2. Autosomes (all others).

Galton's Law is true of 50% autosomal inheritance from each of the parents, barring any genotypic differences caused by mutations that have presently occured, and phenotypic differences by the switching processes of regulatory dna, or the suppression of recessive genes caused by the dominant genes of whichever parent's contribution.

Galton's law (of autosome percentages) is TRUE across multiple generations only regarding the genetic material involved, but NOT TRUE of the phenotypes exhibited, or additional regard of the selection pressures made by breeders (both advertant/inadvertant) across the generations.

And of course, Galton's Law also does not apply to the sex chromosomes, which may play a significant hand in the expression of polygenic traits with their autosomal counterparts, and have greater influence across the span of generations.  A Y-chromosome may be passed "in whole" with 100% accuracy for several generations and beyond (sire-line only), while the influence of an X-chromosome could be as high as 50% in the fourth generation, depending on pedigree position.

Autosomal inheritance of RAW genetic material is easy to calculate accurately, but the passing of WHOLE characterisics is not one and the same.  There are many ways in which traits are either expressed or supressed, or altogether eliminated in breeding.  And it's important to remember; GENES ARE NOT SYNONOMOUS OF TRAITS.  Traits, are like the footprints left behind.

Very educating Daryl

Ziegerfarm, excellent post, excellent knowledge

The exact text in italics is as follows:

"We shall see later on that the most important thing for the breed is the crossing of the third and fourth family line, that is the great- and the great-great-grandparents". 

I am just curious why he laid emphasis on it, and how much importance do PDB members give to it..

Can you provide a quote, since it wasn't clear he was discussing linebreeding at all?

"and phenotypic differences by the switching processes of regulatory dna, or the suppression of recessive genes caused by the dominant genes of whichever parent's contribution."

Does this  account for the idea that certain dogs are more preponent than others? Some dogs, from all of great phenotype of comparable heritage, can pass their traits better.