Saturday, September 07, 2013

Clear Thinking on Genetic Diversity

Every breeder of domestic animals with a closed studbook should read this, all of it. Most important is the section the writer, Jeffrey Bragg, calls  Principles for the Breeder.

 (MANY thanks to Daniela Imre).

"The great majority of dog breeds have been bred within a completely closed studbook for sixty to a hundred years or longer, with little or no fresh genetic input throughout the entire period from breed foundation to the present. In most cases the stud book was opened for a year or two, a small number of founders, often closely related to one another, were registered, and the stud book was then closed. Thereafter, only dogs descended from the founders could be registered. And for those sixty to a hundred or more years, artificial selection, random drift, bottlenecking and other forms of attrition took their toll of whatever genetic diversity was present in the founder group. It is exactly as though a bank account had been established with a single initial deposit (the genetic diversity of the founders), with no further deposits permitted; meanwhile bank fees and direct debits (diversity losses from drift, selection, etc.) chiselled away at the balance. It is a sure and certain recipe for bankruptcy.

"Similarly, many individual bloodlines have been treated in exactly the same way, bred in relative genetic isolation from other bloodlines -- except that in this case additional deposits are at least allowed, in the form of bloodline outcrosses. Therefore each breeder probably ought to consider the desirability of locating and using a true outcross within his or her own breed (unrelated to one's own stock for at least ten to fifteen generations) at least once and to integrate the resulting progeny into one's kennel bloodline.


"If there is any possibility whatsoever to import unrelated stock from a breed's country of origin, one ought seriously to consider doing just that. This is mainly possible in the case of landrace breeds, in which an autochthonous regional population remains in the country of origin, independent of exported stock that may have become a registered breed in other countries. Examples of such situations would be the population of desert-bred coursing sighthounds in the Near East, relative to the Saluki breed in Europe and North America, or the relict populations of autochthonous arctic spitz-type sled dogs relative to the modern Siberian Husky, Alaskan Malamute, Samoyed, et al.

"It would be difficult to overestimate the genetic value of a single import animal, unrelated to the registered breed population for scores of generations but stemming from exactly the same fountainhead. This I would term the Holy Grail of the diversity breeder -- the ideal controlled-outcross situation in which an immediate significant increase in healthy genetic diversity may be obtained at little to no cost in terms of breed type and purpose. (That the Canadian Kennel Club rejected this option for the Siberian Husky in 1994 demonstrates, I believe, the true extent to which the umbrella all-breed registries represent an obstacle to genetic health and true breed welfare and improvement.)"

Are you listening, AKC? Saluki Club?

Oh right, all those "Holy Grail" dogs are... mongrels.


Cynthia said...

Isn't that what the Society for the Perpetuation of Desert Bred Salukis is for? It might take three generations to get that blood in, but at least the option is there.

Steve Bodio said...

Ask them about brindle.

Sarcasm aside, trickling in genes after three generations was not practical enough, and I believe it is getting more, not less, restrictive. Nor does it allow a lot of good dogs currently in the US to be considered salukis, apparently because they come from east of the historic founding individuals.

And what about every other AKC breed? Most if not all come from even fewer founders.

Retrieverman said...

Actually don't ask them about brindle :)

Bragg has so many great articles on his site.

Golden retrievers have relatively recent blood from Labrador, flat-coat, and even curly-coated retrievers, but people treat them like they are a different species from all the rest. As a Kennel Club recognized breed, they are only a little over a hundred years old. Before that, they were part of the flat-coated retriever gene pool, which was actually much, much more diverse than it is now.

No one wants to talk about population genetics in dogs. In the dog fancy, it's as if this science doesn't exist.

Indeed, if it were paid more attention to, it would be hard to breed dogs for competition. You would have to breed for a excellence across the gene pool, which requires people to get along and work together.

In dogs, that's unfortunately not all that common.

Everyone wants to celebrate outstanding sires. Everyone wants to have bred that "great producer."

This is as true for trial-bred dogs as it is show dogs.

If we are going to reform the way dogs are bred, we're going to have to change culture and values.

You can't say that dog shows are bad and the way to save them is trials.

This is the logical fallacy of that argument.

You're doing exactly the same thing to the gene pools through breeding an elite trial stock as you're doing through breeding show dogs.

The only exception is you're not breeding freakazoid pekes and Neo mastiffs.

Anonymous said...

Gosh, SO MUCH I can rattle on regarding this subject! And a small world it is indeed--Jefferey Bragg and I have had some SUPER exchanges via E-mail over the years--he does indeed have a SUPER website--whether you are into sled dogs specifically or not(I AM!). We had some great discussions(along with quite a few other commentors) on one of his blogs in the past regarding(gasp!) daring to add WOLF genes to any existing dog breed to improve it--and it was great to be able to actually discuss the topic sensibly without the knee-jerk PC attitudes most IGNORANT people have on the subject(i. e.--people VEHEMENTLY against the idea are usually people with ZERO actual experience with the animals!)--more on THAT in the next section posted on this subject.....Thing is, Conformation Show folks AREN'T likely going to change(in OUR lifetime, anyway)--and they have dominated peoples' views on what constitutes "proper" Front-Yard dog breeding for some time--like Retrieverman said also--breeding for just "Trials" can have just as deleterious effect on a sensible all-around dog as well. Take sled dogs specifically(and Siberian Huskies particularly)--although they will NEVER accept this, you can learn more about what constitites a good, functional sled dog in 5 minutes on the back of a sled, compared to decades trotting them about on a short leash around a show ring! On the other hand, JUST breeding them for RACING often creates overly hyper, high strung, NUTSO dogs that just want to run, run, run, RUN! Let me tell you, for a FUNCTIONAL(for camping, trapping, survival, recreation) team, THAT is about as useless as the poorly structured, genetically weak dogs in the show ring! A team that goes careening off into the blue scattering your supplies to the 4 directions IS NOT very functional! So called "Races" SHOULD emphasize more on pulling ability, obedience and tractability, just common good sense and temperment, not too mention actually being able to work and THRIVE in Arctic conditions--not needing heated dog boxes between races, and hay beds to sleep on, and incredibly expensive foods to function! Instead of just being THE FASTEST--too much Hare, and too little sensible Tortoise being bred into the Racers. What dog breeding needs more than ever is ANOTHER PERSPECTIVE--people that breed healthy, functional, sensible dogs, and that don't make it into ANY TYPE of COMPETITION, and have no qualms about mixing things up to get that(as have sensible native peoples since the primate/wolf relationship began!). But our voices are still too small, and need more exposure--which is WHY Mister Bodio, you need to write a specific SIGHTHOUND book(someday, in all that spare time you have!) regarding all this! That's not a hint, but a DEMAND!!!!!!!L. B.