My end of module project for the course I am doing requires me to answer the following:

"Selectively breeding from within a breed for specific qualities is blamed by some for the apparent increase in hereditary problems, is this view justified?"

Just looking for some different opinions if anyone would like to give me theirs?

I am kinda on the fence with what I think at the moment! Obviously I am doing research but would really like the opinions of people as well rather than just reading through reports and stuff!

Thanks!

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Do you want opinions or facts? Not sure what your project is actually studying, here.

If you want facts there are tonnes of peer reviewed articles on the subject. They discuss the factors that lead to small gene pool issues and the effects on breeding from small gene pools. There are agreed consequences of small gene pool breeding which have been known for many, many years.

Does your project study opinions on the matter? Do you identify any groups of people expressing opinions?

Happy to help but not sure of your parameters.

I would help if I knew what hereditary meaant (don't laugh, I'm under 13! I have an excuse!).

It means passed on through genes. So you inherited genes from your mum and your dad and your children will inherit genes from you in the future. So if something is "hereditary" it means that it is something you are born with in your genes

Selective breeding a long time ago before health testing became available available is what has caused problems to be bred into a breed. Selective breeding nowadays, with health tets, is helping to eliminate problems within each breed

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SOMETIMES YOUR KNIGHT IN SHINING ARMOUR IS MERELY AN IDIOT WRAPPED IN TINFOIL

Hmm, still confusedp! Oh, nevermind

Something you get from your parents eg. your eye colour is "inherited" from your parents.

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SOMETIMES YOUR KNIGHT IN SHINING ARMOUR IS MERELY AN IDIOT WRAPPED IN TINFOIL

it was a mixture of selective breeding and over breeding

for example - using horses I'm afraid

All Thoroughbred Horses in the UK (potentially world?) can trace their ancestry back to 4 Arabian stallions

If one of those stallions had been the carrier of a genetic disease then it could affect over 1/4-1/2 of all thoroughbreds alive today due to his progeny being bred together

This genetic 'bottleneck' has happened many times in the dog world - some breeds only have 10% of the genetic diversity they had 50-100 years ago! This is generally the result of a stud dog fathering too many litters and the obsession with pedigrees/breeding to 'show type' and so on meaning people overused one dog and ignored another completelyit's why imports of foreign lines are now being allowed by the KC in certain breeds

I believe in the Dalmation as an example it was only around 10 dogs/bitches with quirks of nature giving them a mutated gene causing the urinary problems that is now considered a 'common' breed problem - but because otherwise they were very good dogs and the testing simply didn't exist back then... they were over bred and prolific amongst their breed, then same again with their offspring

Another sample to look at is the European Royal Families - they were all haemophiliacs because of cousins marrying each other

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ok hereditary means what you get from parents rather than chance issues. There are a lot of false stories about inherited conditions and how breeding for showing can lead to more of these. There are issues around limited gene pools - but some issues are across breeds, for instance hip displacia. Other problems are limited to certain breeds or groups of breeds, so eg collie eye anomoly affects collie breeds - border collies, rough/smooth collies, shelties etc plus other breeds which have collie in them eg lancashire heelers and nova scotia duck tolling retrievers. Other things like PRA are across a number of breeds. Some breeds have more inherited issues to be aware of and others have less. Some new things are found - like recently a nasty thing called Trapped Neurophil Symdrome TNS in border collies. Interestingly this came to light when breeders in Australia were dealing with another fatal disease - CL - which is a storage disease. Without a DNA test they got together and worked out where the CL was and avoided it... it appears that those lines free from CL however had TNS. This has occurred before but without any individual symptoms it was put down to 'fading puppy syndrome'. A clever chap in Australia, Alan Wilton, found the DNA test for both diseases and now there's no excuse for not testing - although a pup died from TNS in the UK only last year. Glaucoma has also recently shown itself in border collies in the last few years. It would be great if there was a DNA test for epilepsy and also hip displacia however they're complex problems, what they call polygenic meaning that not only are there many genes involved but also that these genes act differently depending on the other genes they're with. Environmental factors are also indicators in both of these, further complicating matters.

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Penny
Funfastquick Agility Dogs

It's thought that the huge increase in numbers of brown border collies is a result not just of 'demand' but also that the most well used stud dog carried brown! Unfortunately he probably also carried collie eye anomoly also explaining the large number of dogs with this disease. Fortunately there's now a DNA test for CEA :-)

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Penny
Funfastquick Agility Dogs