> ***Yes, I certainly do believe that this is possible, especially if it > is done whilst limiting the amount of in-breeding that was one of the > causes of the problem in the first place, rather than building walls > around an already constrained gene pool.
What you don't understand is that you CAN'T eliminate a genetic fault without in-breeding (or set a breed type without in-breeding). You can hide it, but you can't eliminate it. If you only hide it you will never reduce the incidence because you won't be able to choose the dogs who are GENETICALLY clear of it if it is hidden--so it will keep right on popping up. Just stop and think about this for a minute. If almost every dog of a particular breed has no hip dysplasia, no MVD, no patellar luxation and no eye problems--they WILL be MUCH more genetically similar to each other than before. It is just the way it is. And there will be loss of genetic diversity and immune function. Let's look at it another way. Life is based on genetic diversity. If we want to start a new breed of dog--we have to do so by eliminating genetic *faults*. In this case (beginning a new breed of dog) a genetic fault can be short hair on a breed we want to be long haired or prick ears on a breed we want to have drop ears--or any one of a variety of *faults*. The only way to get rid of these *faults* and to create a group of dogs who are similar to each other is to IN-BREED--to make them more genetically similar to each other so they don't have those prick ears or short coat! Trying to GENETICALLY eliminate hip dysplasia is no different from trying to eliminate short hair! How could it be?! > However, I'd be very interested in specific research that shows > that careful selection of dogs that don't have hip, eye, heart and > patella defects coupled with attempts to reduce in-breeding leads to > immune disorders or the early onset of cancer. Again, you can't *carefully select* dogs that don't have hip, eye, heart and patella defects without doing a type of *in-breeding*! If every dog has the same structure of the hip area, the same fitness, the same muscle tone, the same good ligaments, tendons and connective tissue so that they don't develop hip dysplasia--their genetic makeup for hip dysplasia will be very similar (if they are the same breed and have the same look) and there will be loss of genetic diversity. I think what might not be understood is that in-breeding is a genetic term that technically has to do with genes and technically nothing to do with pedigrees. The pedigrees are a tool to help us because we can assume that most dogs of a particular line are probably more genetically similar to each other than a group of dogs from a variety of unrelated lines. But it doesn't have to be that way. A brother and sister can be VERY different in genetic makeup due to the haphazard way in which genes combine. (Remember if they are VERY different from each other in genetic makeup however, if one appears clear of hip dysplasia--it won't mean the other will be clear, because they each have a different genetic makeup!) But if we take two Cavaliers from entirely different lines and both have a very similarly shaped, large round, dark eye--you can be sure the genetic makeup of those dogs for eyes is very similar. So they are not genetically diverse from one another regarding eyes. If you add hips, hearts, patellas and other things--it only gets worse--you lose more and more genetic diversity. Cavaliers already have their share of immune system problems therefore they already have some loss of genetic diversity. We certainly don't want to make things any worse. We do NOT have the control we wish to have. Nature is in control. We must preserve genetic diversity above all else. Laura Lang ========================================================= "Magic Commands": to stop receiving mail for awhile, click here and send the email: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL to start it up gain click here: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL E-mail [EMAIL PROTECTED] for assistance. Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html All e-mail sent through CKCS-L is Copyright 2002 by its original author.
