Recessive genes and breeding....

Diana made a comment about Cooper being inbred, in response to my writing about the AKC judges making snarky comments about his heritage. (As an aside - check Diana's writing. It's excellent!)
OK. The long coat is a recessive - also called a "throwback" - gene. Essentially a gene for a trait that both parents carry, but do not exhibit. The long haired gene in Rottweilers and other molosser breeds is thought to relate back to the early northern European mastiff type dogs from which Rottweilers are descended. Andrew Brace in his wonderful book "The Ultimate Rottweiler" states that long haired Rotties tend to be very heavy boned and laid back. The woman who did the litter evaluation on Coop's litter said the same thing.
If both parents carry the recessive gene, offspring has a roughly 25% chance to exhibit the trait but it does NOT mean they carry the gene themselves.
Cooper has donated some DNA to a study being run at MSU vet school. They are attempting to identify the gene (or gene marker, I'm not sure of terminology) for the long haired trait.
Both Cooper's sire and dam had regular coats. Both were finished champions with both show and working titles. His sire is Evrmor's U R The One. If you look at the roster of dogs entered at Westminster, you will see the kennel name and many of his progeny! Cooper came from a very carefully thought out breeding - currently there is no way to foretell things like fluffieness!
Fluffy Rottweilers are very uncommon, but they can happen just as easily in carefully planned breedings as well as poorly planned ones. I had put a deposit on the litter before they were born, saying I wanted "pet" quality since I have no interest in breeding or conformation showing.
Cooper has a "limited" AKC registration. This means he is eligible for everything except the conformation show ring - the long coat is a disqualifying fault - and were he to be bred, his progeny would not be AKC-registerable.
Except for the fluff, he is quite gorgeous. Ideal size (just shy of 100lbs), beautiful head, strong bone, gorgeous topline, feet, markings, everything.
Why are some things considered not part of the breed standard and disqualifying faults? Well, first, if there were no breed standards to uphold, there wouldn't be breeds, really! There would just be types. Second, most criteria are there for a reason. Some traits - like white boxers and Dobermans - also carry deafness and horrible skin problems along with the gene for albinism. Many criteria are tailored to the original purpose of the breed. Rottweilers were cattle drovers, guard and carting dogs, and all around farm worker dogs, used to go dozens of miles a day in all sorts of weather conditions. Unlike rough collies, Cooper lacks a harsh water repellent outer coat. This means when he gets wet, he gets wet to the skin and STAYS wet for ages. In his original job, he would stay cold and wet for days!
Despite the fluffy thing, he is 100% Rottweiler. His temperament is absolutely classic. Aloof with strangers, yet adores all children. Once he likes someone, he loves them forever. Prone to bossiness and dominance, yet extremely biddable with honest, fair training. Calm, yet give him a job and he has tremendous drive and enthusiasm. Incredibly smart with the ability to think things through and problem solve. Mostly horrible and overbearing with other dogs (although tolerant with puppies and little dogs.) Very alert and strongly bonds with his humans. Naturally protective and territorial, but since I'm the boss he is calm and welcomes most everyone, at least when I'm here.
This describes every Rottweiler I've owned except Daphne, actually.
So. Just wanted to clear things up and defend my junkyard dog, haha! I sure hope Cooper has his daddy's longevity...