Site-specific frogs: is it possible?

[Toby_H]

Originally Posted by MonarchzMan

Inbreeding has bad effects with many generations of inbreeding. If we go under the assumption that full siblings were constantly bred which would have the worst effects of inbreeding, you'd still need to have a decent number of generations to have those effects. For ease of argument, we'll say 5.

Originally Posted by MonarchzMan

I'm not suggesting that it's okay to breed half siblings or parents to offspring or whatever.

In the first quote you did suggest that it isn’t a big deal to inbreed and based your remaining argument on an assumption about compounding inbreeding. I removed myself from the debate pointing out TWI’s ASN guidelines disapprove of inbreeding any closer than second cousin to second cousin. (Brink’s, is that a better way to put it: TWI’s ASN guidelines?)

I’ve agreed that it is possible that available frogs are of a low F#… and I’ve stated that I’m not eager to simply “assume” this… You’ve also promoted not assuming on other topics (locale data) so I thought you’d understand… I’ve also asked for details on breeders/suppliers who make such information available… I’ve also stated I’ve made inquires without success… But you repeatedly ignore my points preventing the conversation from moving forward…

Originally Posted by Ed

Actually if one reads through all of the abstracts (better if one reads the articles but I don't have pdfs..) one notices that there are problems that do not arise from indeterminate morphological characteristics that cause problems, look at Outbreeding depression in the common frog, Rana temporaria; Conservation Genetics; Volume 6, Number 2 (205-211); where depending on the outcross performed there were increased rates of deformation of the tadpoles.

I understand with your profession you have access to articles/studies that I don’t have access to or you cannot share access to. I don’t hold that against you and instead value it.

But are there other case studies that prove at other times the opposite is true? In my reading I find that inbreeding depression is readily accepted as a valid concern that is warned against… and out crossing has much less potential danger and the bulk of it’s dangers are in regards to loosing a trait that is environmentally specific (thus inconsequential to animals removed from that environment). Does the case study you referenced represent ‘the rule’ or ‘the exception’ to it?



Also, I’m repeatedly being accused of overly assuming that out crossing holds possible benefits… but every argument in opposition is just as assumptuous. There are ‘related studies’ going both ways. If someone is going to take the privilege of assuming, they have to in turn give it… and if they are going to reject all statements containing an assumption, they have to stop making them...



I am not saying “locale specific” breeding projects are bad… I am saying there is more to a breeding project than being locale specific… and that when a perfect locale specific breeding project is not possible, out crossing between locales may be a better way to create healthy frogs than allow bottlenecking of a locale to occur.

Repeatedly on this site I see posts which seem to use ‘locale purity’ to trump all other breeding standards. Yet I’ve read no evidence that this is in the best interests of the health of our frogs.

[zBrinks]

Toby,

If you're looking for low F#s of particular localities/import dates, let me know. It's really not all that hard to find them, it's just a matter of asking the right people. You may have to get on a list to wait for offspring, but if you're after non-inbred frogs, I can't see that being an issue. Post a list of what you're wanting to look for, and I'll be glad to help you out. I've never had an issue of tracking down low F# frogs when I've put in the effort.

[jubjub47]

I've been reading through this entire thread and just want to make one comment on the lineage question that you keep bringing up. It's really quite simple so I'm surprised you haven't already come to this conclusion. You first contact the breeder you purchased your animals from. Ask them if they know the lineage. If they do not, simply ask them who they purchased from and contact that person. Keep repeating this process until you've found the info you're looking for. I've been able to find lineage data on all my frogs using this same process. It just takes a bit of work and is really not all that hard to do.

As for the other stuff, I really don't care to be involved.

[edwardsatc]

Originally Posted by Toby_H

But are there other case studies that prove at other times the opposite is true? In my reading I find that inbreeding depression is readily accepted as a valid concern that is warned against… and out crossing has much less potential danger and the bulk of it’s dangers are in regards to loosing a trait that is environmentally specific (thus inconsequential to animals removed from that environment).

Any peer reviewed literature? Citations?

[Ed]

Originally Posted by Toby_H

But are there other case studies that prove at other times the opposite is true? In my reading I find that inbreeding depression is readily accepted as a valid concern that is warned against… and out crossing has much less potential danger and the bulk of it’s dangers are in regards to loosing a trait that is environmentally specific (thus inconsequential to animals removed from that environment). Does the case study you referenced represent ‘the rule’ or ‘the exception’ to it?

In the past, there was a lot more emphasis put on outbreeding between populations to increase genetic diversity as it was percieved that the positives consistently outweighed the negatives for many species. This has carried over into the literature today however an increasing understanding (and increasing body of information across taxa) of locality/population genetics and gene flow between populations is changing those beliefs/assumptions on outcrossings. If you have a highly mobile population in which gene flow is relatively unimpeded you don't tend to have the problems seen in outcrossing depression and the effects of inbreeding depression are of greater concern, while populations that are not mobile or are insular to some degree which causes gene flow to be very slow are at much greater risk of outbreeding depression than inbreeding depression. One has to have an understanding of the pattern of distribution.. many anurans species (including dendrobatids) have a patchy distribution where there is a local population surrounding by a population sink (for example the last intergrading in D. tinctorius was about 10,000 years ago (see http://bnoonan.org/Papers/Noonan_Gaucher_06.pdf for example)) which severely restricts the rate of gene flow between the populations increasing the risk of outbreeding depression .
One has to keep in mind that this is a currently increasing field of understanding.

Along this discussion, (and I may have missed it), even the "Panama" auratus that are in the hobby that are the result on multiple imports over the last 25 years (or more) have a place in ASN. Thier population should be maintained in the hobby as well as those of known origins...

Ed

[MonarchzMan]

Originally Posted by Toby_H

In the first quote you did suggest that it isn’t a big deal to inbreed and based your remaining argument on an assumption about compounding inbreeding. I removed myself from the debate pointing out TWI’s ASN guidelines disapprove of inbreeding any closer than second cousin to second cousin. (Brink’s, is that a better way to put it: TWI’s ASN guidelines?)

I’ve agreed that it is possible that available frogs are of a low F#… and I’ve stated that I’m not eager to simply “assume” this… You’ve also promoted not assuming on other topics (locale data) so I thought you’d understand… I’ve also asked for details on breeders/suppliers who make such information available… I’ve also stated I’ve made inquires without success… But you repeatedly ignore my points preventing the conversation from moving forward…

No, what I was suggesting is that inbreeding, in any substantial form, is unlikely to be in a random set of frogs. Now, it could happen, but unless it has been done progressively for many generations, the impact of inbreeding will be minimal, if at all noticeable. And as I've stated before, inbreeding can be corrected rather easily.

As for the low F#. I wasn't saying that all frogs in the hobby are a few generations in. I was say how the majority of the frogs in the hobby originate from sources that have been imported relatively recently with only a few exceptions. And for a line of frogs that has been in the hobby for 5 years, you're not going to get F5s out of that line. I don't care if you dust fruit flies with viagra, the frogs just are not going to reproduce that fast. So in order to get a lot of generations, you need to have a really long time in the hobby, and the fact of the matter is that most frog lines have not been in the hobby that long.

I understand with your profession you have access to articles/studies that I don’t have access to or you cannot share access to. I don’t hold that against you and instead value it.

You can actually get a significant amount of information on peer reviewed literature from Google Scholar.

But are there other case studies that prove at other times the opposite is true? In my reading I find that inbreeding depression is readily accepted as a valid concern that is warned against… and out crossing has much less potential danger and the bulk of it’s dangers are in regards to loosing a trait that is environmentally specific (thus inconsequential to animals removed from that environment). Does the case study you referenced represent ‘the rule’ or ‘the exception’ to it?

Where are you getting that outcrossing is bad in natural environments but not artificial ones?

Also, I’m repeatedly being accused of overly assuming that out crossing holds possible benefits… but every argument in opposition is just as assumptuous. There are ‘related studies’ going both ways. If someone is going to take the privilege of assuming, they have to in turn give it… and if they are going to reject all statements containing an assumption, they have to stop making them...

Can you provide those studies that support your stance?

I guess I would look at it in that there is a chance that something bad can result from outbreeding, for reasons that Ed discussed and for literature already covered. It's foolish to assume that it's completely beneficial, so given that, why do it? The only breeding method that ensures that there are no depressions is locale-specific breeding.

I am not saying “locale specific” breeding projects are bad… I am saying there is more to a breeding project than being locale specific… and that when a perfect locale specific breeding project is not possible, out crossing between locales may be a better way to create healthy frogs than allow bottlenecking of a locale to occur.

Repeatedly on this site I see posts which seem to use ‘locale purity’ to trump all other breeding standards. Yet I’ve read no evidence that this is in the best interests of the health of our frogs.

What population of frogs in the hobby is so constrained that there is absolutely no option but outcrossing or inbreeding?

[Ed]

This article actually gives a good overview of both inbreeding risks and outbreeding risks... It took awhile to find a free online copy

http://www.montana.edu/~wwwbi/staff/...#37;202007.pdf

Edmands, Suzanne; 2007;Between a rock and a hard place: evaluating the relative risks
of inbreeding and outbreeding for conservation and management; Molecular Ecology 16, 463–475

Note; that inbreeding and outbreeding effects can be easily confused and the recommendations seen in the discussion section of the article on attempting to prevent the occurance of the effects of inbreeding/outbreeding effects. Both of these are significant risks and can have significant effects on the survivial of a captive population as the effects of either/both can reduce the ability of the animal to resist disease pathogens common in captive situations (like saprolegnia..)

Ed

[Toby_H]

I’m sorry for my part in allowing this “conversation” to turn into an “argument”…

The tit for tat, quote for quote, posting has created several half-relevant tangents and have drifted beyond ‘debating’ into fault finding and nit picking. I hope we can get back to sharing ideas and get away from ‘defeating’ one another.


My point as a whole:

I’m in full support of pursuing the best standards we can in our breeding programs and I believe that TWI’s ASN guidelines could be considered ideal when no compromise is made. But if compromises are going to be made, if the goal of creating a reintroduction stock is not kept, I think that mixing locales is a reasonable option to consider.

To instantly suggest crossing locales will yield negative results is overly presumptuous. Also note I have not insisted that out crossing will yield better results. I proposed in the case compromise must be made, when reintroduction is not the goal, out crossing locales may have less negative impact on the frogs health than other compromises one may consider.

In the case where to small of a founder stock is available, you will not have the diversity necessary to reflect the allele ratio of the wild population. Therefore this will not yield a “genetic snapshot” of that locale. When using to small of a founding stock, it becomes more difficult to avoid inbreeding (an ASN guideline). Therefore allowing out crossing allows a larger ‘founder stock’ (though noted this will not be a locale specific project).



I know that some of you value “site specific” populations quite firmly. While I don’t want “designer frogs”, or completely unnatural hybrids, I don’t think I quite ‘get’ why having site specific frogs are so important. I’d be interested in hearing your reasoning…

[skylsdale]

Originally Posted by Toby_H

I know that some of you value “site specific” populations quite firmly. While I don’t want “designer frogs”, or completely unnatural hybrids, I don’t think I quite ‘get’ why having site specific frogs are so important. I’d be interested in hearing your reasoning…

As for me personally, I talked about this on the very first page of the thread:

Originally Posted by skylsdale

Just to include another dynamic to the discussion, I think it's important to realize that not every decision has to be made on the basis of conservation (and this is coming from someone who is a strong advocate of conservation). For many people this will never be anything more than simply enjoying some tropical frogs in a tank in their living rooms, and that's okay. For these same people, simply having and enjoying an auratus that originated from somewhere in Costa Rica is enough, so we have to realize that there is still value to the non-site-specific animals already in the hobby.

However, as a hobbyist, I am personally extremely interested in the specificity of a frog's origin. To me, one of the fascinating things about these amphibians is how they've evolved and adapted so specifically and uniquely to (and along with) their unique environments...so part of the interest and fun for me is knowing their locales. Knowing that the pumilio from the Salt Creek area of Isla Bastimentos are different from the Red Frog Beach area from the cemetary, etc. is part of what continues to draw me into this hobby and personal research and fuels my fascination.

[Ed]

hi Toby

Originally Posted by Toby_H

To instantly suggest crossing locales will yield negative results is overly presumptuous. Also note I have not insisted that out crossing will yield better results. I proposed in the case compromise must be made, when reintroduction is not the goal, out crossing locales may have less negative impact on the frogs health than other compromises one may consider.

In the case where to small of a founder stock is available, you will not have the diversity necessary to reflect the allele ratio of the wild population. Therefore this will not yield a “genetic snapshot” of that locale. When using to small of a founding stock, it becomes more difficult to avoid inbreeding (an ASN guideline). Therefore allowing out crossing allows a larger ‘founder stock’ (though noted this will not be a locale specific project).

Did you read the paper that discusses inbreeding and outbreeding risks that I cited above? The evidence is there and it is sufficiently strong enough to support the premise that outbreeding locales will result in in negative consequences to the population as a whole...

In addition, depending on the population of origin in question, a small number of founders can easily capture the genetic frequency of that population so one cannot assume a priori that a small founder population
1) does not capture an accurate genetic snapshot of that population
2) that it makes it more difficult to avoid inbreeding...

These two positions are not supported by what is currently known in the conservation literature. I'm not going to engage in further argument over these points as they have been hashed and rehashed in this thread, I am instead going to state again, that they are not supported by the current body of literature for sustaining a population in captivity long term and that by outcrossing two locales that are isolated you may do as much harm (if not more) than multiple generations of inbreeding. For a start, I strongly suggest the reference I provided above...

Ed