Inbreeding?

[Kathryn_]

Since you seem to be so insistant that it is a problem how about you show us some examples of problems caused by line breeding reptiles.

Have you read my posts? I've stated repeatedly that I'm not aware of any current problems that have yet occurred as a result of inbreeding reptiles, partly because I can't find any good research, partly because I'm not sure people would recognise such diseases for what they were if they did show up, and partly because I'm not sure people would be forthcoming if they did produce sick animals.

Even if these are coincidences, and there are indeed no current examples of serious genetic disease in reptiles, it will only take two het animals producing a clutch of eight to create at least one, probably two, possibly three very sick animals. If those parent animals come from a long line of inbreeding then they are likely to have dozens of close relatives also carrying that allele. There was a first time for Familial Alzheimer's, there was a first time for Tay-Sachs, and there might very well be many first times for many genetic diseases in different reptile species that will lead to a lot of very sick animals leading very short andunhappy lives. It is a risk that is multiplied many, many times by inbreeding, and in my opinion, and unnecessary and careless one.

 

[junglepython2]

So what?? The sick animals wouldn't be bred and therefore the recessive conditions quickly weaned out.

 

[Nagraj]

So what?? The sick animals wouldn't be bred and therefore the recessive conditions quickly weaned out.

1/ Is it ok to knowingly produce defective animals for profit?

2/ Fatal genetic conditions are not always revealed pre breeding age.

 

[Hickson]

A few people have mentioned scientific papers that have been written on the subject, and even a book.

I'd like those people to cite the title and author of those publications as I'd be very interested in reading what has and hasn't been proven scientifically, as opposed to some of the broad generalisations made previously in this thread.



Hix

 

[notechistiger]

It is a risk

I've stated repeatedly that I'm not aware of any current problems that have yet occurred as a result
of inbreeding reptiles, partly because I can't find any good research,

You seem to be basing your opinions upon nothing but evidence produced from tests on mammals and fish. You can't make an informative arguement unless you know all the facts- which you don't, because as you say, there is no good research that you can find. There are people who have been breeding reptiles for many years (and I can't stress that "many" enough), and have found no evidence of genetic problems due to inbreeding.

My point is, I'm much more willing to take the word of an experienced keeper over your opinions.

~ notechistiger.

 

[Kathryn_]

Someone else very helpfully dug me up an article by some nice biologists from Berkley in the states: http://evolution.berkeley.edu/evosite/relevance/IIIA1Inbreeding.shtml

Can anyone find me a referenced article or a chapter in a text book, by a qualified geneticist, written in the last twenty years, that argues that there's no chance of inbreeding producing as yet undiscovered genetic disease in reptiles? Not that isolated incidences have occurred without producing ill effects, which is anecdotal evidence and nothing more, but that they couldn't possibly? Anyone? Bueller?

have found no evidence of genetic problems due to inbreeding.

People keep raising this as if it's hard proof of anything other than luck, but for argument's sake let's treat it like it could be. I'd be very curious to see their non-viable offspring rates over ten generations of sib-sib breeding. Five, even. Poor feeders, dead eggs, the lot - anything that didn't make it to six months old. As you agree, part of the problem is lack of good information. We have many breeders on here, non? I would assume they all keep good records? Let's assume everyone's completely honest and see if we can compare mortality rates over five gens sib-sib or sib-parent inbreeding versus five gens normal breeding, in the same species. People can pm me their records privately, could even email them to me anonymously. No-one's got anything to lose, I won't even post results if they'd prefer I didn't - it's for my own curiosity. The more generations and pairs I get info on, the more realistic the results. Any takers? The Anteresia group seems a likely possibility?

 

[cris]

I can guarantee you that inbreeding will produce currently undiscovered genetic disease. It isnt really a problem though, there is massive amounts evidence showing inbreeding not to be a problem over many generations across various animals. I dont see why fundamental genetic theory would change for reptiles.

 

[Blondie]

What deformities were observed in the Adders in Sweden?

I dont think any qualified geneticist would argue that there is no chance of inbreeding producing undiscovered genetic diseases but the chances are, after 10+ generations you would have discovered them or bred them out.

 

[DanTheMan]

Sorry if this has been said but i really can t be bothered reading the 4 pages, but I think its ok for a bit, but after a few generations you would probably need to introduced some new genes.
Would be best to give them a bit of genetic variation

 

[Blondie]

I agree there should be some variance. I dont think there is sufficient evidence either way and certainly dont think inbreeding reptiles is "positively irresponsible" provided you are not knowingly breeding defects for the sake of breeding.

 

[hornet]

Then technically I'm not wrong... I didn't say you couldn't do more. This is just info I've collected from experienced breeders that I know and seemingly reliable information found on the net, rather then what I heard on a forum. I'm not saying a forum isn't a great source of information, just there is alot of people throwing round information that may not be 100% accurate on internet forums.

wasnt haven a go at you mate, just being a smart@ss

 

[junglepython2]

1/ Is it ok to knowingly produce defective animals for profit?

2/ Fatal genetic conditions are not always revealed pre breeding age.

1. You are not knowingly producing defective animals if they pop up out of the blue, also I can't see how producing defective animals can be profitable.

2. True, but unlike humans snakes breed well into their old age so their overall number of offspring will still be reduced compared to a healthy snake even if they make it to breeding age, so the overall incidence of the negative recessive allele will still be reduced in the population.

 

[wokka]

Surely the risk of inbreeding depends upon the genetics of the foundation animals. If the founding animal has an undesirable trait that undesirability may be compounded to produce a negative effect from inbreeding. I believe (not fact just opinion) in general there is no negative effect from inbreeding Australian Pythons,
However, My observation with Albino Olives is that there are not as many around as there should be given the time and consequent opportunity which has passed since the original albino olive was caught in Darwin. Whilst some of the falures with Albino Olives may be put down to management I believe there is heretible fault which limits reproduction in these animals. With this in mind I try to breed White to het to bring in new blood which may overide this fault.There is something like 100 breeding age animals in Austrlia yet last year only about 20 white olives were produced. This makes me think something is wrong. The market reflects this with a premium paid for animals which breed freely and a reduced price for those from less successful pairings. Added to the difficulties in breeding seems to come difficulties with feeding. It seems the original Albino Olive may have carried some undesirable as well as desirable traits.

 

[Nagraj]

1. You are not knowingly producing defective animals if they pop up out of the blue, also I can't see how producing defective animals can be profitable.

Oh, but you are knowingly doing so, by continually line beeding animals for a certain trait when you know that the chance of a defect increases with every incestuous breeding you do.

Obviously it's not the visually defective animals which are profitable but the apparently healthy siblings which have the desired trait but which almost certainly carry defective genes as well.

 

[wokka]

They all end up coming from the one alibino olive don't they?
They darwin's all come from Blondie

Not true! Blondie was a Territory Wildlife Park animal lent to Soutrhern Cross on breeding loan. Blondie was found in Darwin. Another line called White Phoenix originated from a wild caught animal from Adelaide River area over 50 kilometers from Darwin.

 

[gregcranston]

I started a thread very simlar to this a couple of months ago: http://www.aussiepythons.com/forum/exotics-other-reptiles/inbreeding-bearded-dragons-86211
However is was relating to bearded dragons more than snakes. Worryingly it seems that inbreeding is quite common in the reptile world.

 

[cris]

Asian house geckos in Australia are a good example to think about, i certainly dont think they are unfit or suffering from abnormally high rates of genetic disease.

 

[Renagade]

Kathyrn,
You're omitting the fact that breeders select their stock from all their available offspring. Animals that are identified as carrying genetic diseases will be culled or at least not bred from. Even in the case where a possible genetic disease may not show up until later in life will be picked up by the breeder as these animals are kept well into adulthood. Lineages carrying genetic diseases become extinct by the hand of the breeder.

"animals that are identified" seem to be the key words in this argument. We can all establish from many past arguments that breeders do indeed inbreed their herps and so far there are no negative effects which have been declared due to this inbreeding. Yes herps may inbreed in the wild, but the chance of 10 generations of brothers and sisters breeding are beyond slim. personally i'd never buy a herp which has knowingly been inbred over 4 or 5 times, that's my opinion, and it is up to the buyer to ask the relevant questons to the breeder of the history and background of the animal they are interested in purchasing.

 

[CodeRed]

"animals that are identified" seem to be the key words in this argument.

Yes, you need to be able to identify defective lines to guarrantee that it will be culled. Eventually if the disease is signifcant you will be able to identify any genetic carriers.

We can all establish from many past arguments that breeders do indeed inbreed their herps and so far there are no negative effects which have been declared due to this inbreeding. Yes herps may inbreed in the wild, but the chance of 10 generations of brothers and sisters breeding are beyond slim. personally i'd never buy a herp which has knowingly been inbred over 4 or 5 times, that's my opinion, and it is up to the buyer to ask the relevant questons to the breeder of the history and background of the animal they are interested in purchasing.

Thats a shame coz then you will miss out on some of the best lines of jungles, blonde macs, albinos, roughies and probably a few more too.

 

[TrueBlue]

wokka, personally i dont think that there is anything heritable wrong with the albino olives, imo its the way they are kept and cycled by most people that is the problem.