Domesticated animals

[thank.darwin]

Dogs and other domesticated animals are very different than their wild counterparts. Domestic animals become domesticated through human selection - for example dog breeders count on variation and mutation and they breed the dogs that have traits that they like. Over time dogs have become less and less varied due to human selection (they look varied but they aren't). These days almost a quarter of all dogs have genetic disorders (not always visible). What should be done to stop such genetic loss in variation? Should we try to stop this or should we continue to breed dogs to our like and dislikes? I would like to hear others opinion on this matter so please feel free to write what you think - dare to be wrong!

[novastar_]

I feel that this should be stopped as it is very cruel to the animals..... Animals have feelings as well..... Have humans ever really think about their feelings and consider their actions towards their pets/animals...

[mith]

What I want to know is how we can breed dogs into so many different breeds without much problems but only now do we realize there are debilitating diseases. When our cavemen forefathers were breeding dogs didn't that cause more defects? Or is the problem only occuring now because we have reached some sort of breeding limit.

[biostudent84]

Most genetic defects in bred dogs come from the fact that to keep dogs "purebred," inbreeding takes place on a regular basis. The more inbreeding there is, the more problems you will have.

[mith]

I mean before dogs were all differentiated into different breeds. I'm talking about when there was only one specie of dog. When cavemen bred these into all the different types didn't the dogs have problems at that onset?

[biostudent84]

I mean before dogs were all differentiated into different breeds. I'm talking about when there was only one specie of dog. When cavemen bred these into all the different types didn't the dogs have problems at that onset?

A number of possibilities exist. One is that the "original dogs" were so genetically simple that they could inbreed without problems...similar to how most plants can do so.

[thank.darwin]

What I want to know is how we can breed dogs into so many different breeds without much problems but only now do we realize there are debilitating diseases. When our cavemen forefathers were breeding dogs didn't that cause more defects? Or is the problem only occuring now because we have reached some sort of breeding limit.

First of all I would like to thank all of you for your input!

Yes mithrilhack - They have just been slowly building up over time. If a dog inherits a defect it might be able to "hide" it with other genes- just cover it up. But when a dog gets hit with two genetic mishaps then the dog suffers the consequences. For example with the HIV virus there is a HIV1 and a HIV2 and each have sublevels of organization. If a person is infected with just one of them then not many major changes occur in the virus but if the person gets hit with both then the virus would have genetic train wreck (correct me if I'm wrong). So over time as there are more and more types of dogs and differences in genes; it became more likely for a dog to inherit more than one defect.

[longtian006]

I had a PhD in Ecology once tell me that it is impossible for Sasquatch to exist, but I forget the reason behind it.

[Darby]

It's possible that the first dog breeds were supplemented for a while with wild captures, to diversify their genomes.

Another possibility is that inbreeding over a lengthy time will remove bad alleles from a population, leaving it genetically healthy in the long run. This has been confirmed several times from populations where inbreeding has been a longtime practice.