# Outbreeding depression



## BrianWI (Feb 4, 2012)

Are there any good article, studies, observational journals on outbreeding depression seen in this hobby (dart frogs)?


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## cbreon (Apr 25, 2005)

There is a bunch posted on dartden as well as some that Ed has posted here...search function will yield some results, here is one for starters compliments of an Ed post

http://www.uvm.edu/rsenr/wfb224/edmands.pdf


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## Dev30ils (May 1, 2012)

I feel like this is not an appropriate topic for the Beginner Discussion area. Perhaps one of the mods should move it somewhere else.


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## BrianWI (Feb 4, 2012)

Since it is part of the "core" beliefs of the board, it may be a very good topic for beginners.

As far as the study referenced, I was looking more on something specific to dart frogs, not a general overview. I understand the concept, just want to see the data as pertains to dart frogs.


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## BrianWI (Feb 4, 2012)

http://www.life.umd.edu/biology/dudashlab/Dudash PDFs for webpage/Frankham et al ConsBiol 2011.x.pdf

Reading that and the referenced dart frog article, do the two combine to support or detract from the practice of breeding locales seperately.

Genetic structure is correlated with phenotypic div... [Mol Ecol. 2010] - PubMed - NCBI


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## thedude (Nov 28, 2007)

BrianWI said:


> http://www.life.umd.edu/biology/dudashlab/Dudash PDFs for webpage/Frankham et al ConsBiol 2011.x.pdf
> 
> Reading that and the referenced dart frog article, do the two combine to support or detract from the practice of breeding locales seperately.
> 
> Genetic structure is correlated with phenotypic div... [Mol Ecol. 2010] - PubMed - NCBI


They seem to support it in my eyes. Especially when it says the risk of outbreeding depression is low when populations have been separated for more than 500 years. That would apply to most dart frog populations I'm aware of. Especially looking at pumilio in the second article since pumilio in the Bocas of Panama have been separated for around 10,000 years. Island populations anyway.I don't have the time right now but I'll look more into it later. I may be able to find more sources through my college database.


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## hypostatic (Apr 25, 2011)

You know, I have a background in biology and the first I've heard about outbreeding depression was on the boards actually (apparently it's something that's been published about in the field of conservation, which I have not studied). None of the genetics classes I've taken have ever mentioned it. And ever since I've been introduced to the idea, I've been a bit skeptical of it.

It seems that this paper (http://www.life.umd.edu/biology/dudashlab/Dudash PDFs for webpag/Frankham et al ConsBiol 2011.x.pdf) focuses mostly on the depression when crossing two varying species (such as species that are diploids crossed with tetraploids). I can understand how this could cause some sort of genomic disturbance in an organism, and this is not what I'm skeptical of. 

What I don't get is how randomly crossing frogs from the same locale (lets say Azureus for example), can lead to outbreeding depression (which I've read before on the boards). I just don't understand the logic behind it. I'd imagine that the odds of any type of depression occurring would be the same as the normal incidence of depression in a population.


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## Baltimore Bryan (Sep 6, 2006)

hypostatic said:


> What I don't get is how randomly crossing frogs from the same locale (lets say Azureus for example), can lead to outbreeding depression (which I've read before on the boards). I just don't understand the logic behind it. I'd imagine that the odds of any type of depression occurring would be the same as the normal incidence of depression in a population.


Maybe I'm misunderstanding what you are saying here, but I believe much of the talk about outbreeding depression here would be crossing two different populations of the same species, such as an azureus with a matecho (both are tinctorius), not breeding two frogs together from the same locale.
Bryan


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## Ed (Sep 19, 2004)

hypostatic said:


> What I don't get is how randomly crossing frogs from the same locale (lets say Azureus for example), can lead to outbreeding depression (which I've read before on the boards). I just don't understand the logic behind it. I'd imagine that the odds of any type of depression occurring would be the same as the normal incidence of depression in a population.


I don't know why it hasn't been taught in your classes since it has been known since the 1970s..

It can and does occur within species... For example, see http://www.environmental-expert.com/Files\6063\articles\5372\LV68M29432114864.pdf 

Within a species, disjunct populations, are at risk to out breeding depression...as it changes locally adapted genes which as examples result in reduced fertility, and/or reduced survivorship of offspring (in this case tadpoles) and even increased deformation (see the above citation)... 
This is even more apparent when you look at things like hatchery raised salmon that have crossed with wild populations (same species) or even in copepods see http://dornsife.usc.edu/labs/edmands/documents/Edmands_1999.pdf

In captive populations, one of the greatest risk comes from lines of animals that have been inbred over successive generations, and then outcrossed to animals either of wildly diverging lines or animals close to the wild populations. See for example (if I remember correctly) http://eliedolgin.com/pdfs/Evolution2007.pdf 
and Inbreeding Depression and Outbreeding Depression Are Evident in Wild-Type Zebrafish Lines 

Some comments,

Ed


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## BrianWI (Feb 4, 2012)

After reading the first article, it seems the often cited outcrossing depression may not be a perfect reason for keeping certain populations isolated from each other in captivity.


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## Ed (Sep 19, 2004)

thedude said:


> They seem to support it in my eyes. Especially when it says the risk of outbreeding depression is low when populations have been separated for more than 500 years.
> 
> 
> > Don't you mean less than 500 years? That is the finding in the citation above....
> ...


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## BrianWI (Feb 4, 2012)

It appears to me that genetic drift is a minor contributor. Selection leads to the differences in the populations. If the two locales have similar environments, even failry long periods of isolation does not mean there will be OD if members of each population are crossed. Further more, if a population was bottlenecked when isolated, genetic rescue effects may mask or be more beneficial than any resulting OD from the recombination of populations.

I would have to say that the concern for OD as a blanket statement is probably incorrect. Instead, each set of isolated populations would have to be examined individually.


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## MonarchzMan (Oct 23, 2006)

BrianWI said:


> It appears to me that genetic drift is a minor contributor. Selection leads to the differences in the populations. If the two locales have similar environments, even failry long periods of isolation does not mean there will be OD if members of each population are crossed. Further more, if a population was bottlenecked when isolated, genetic rescue effects may mask or be more beneficial than any resulting OD from the recombination of populations.
> 
> I would have to say that the concern for OD as a blanket statement is probably incorrect. Instead, each set of isolated populations would have to be examined individually.


It seems pretty obvious that, if you have two populations that look vastly different, that they are not subjected to the same environment. You're not thinking of all the selective pressures that these frogs have, from food to predators to climate. No population is going to be the same. With the amount of time these populations have been isolated, I would say it's naive to suggest that they haven't developed their own locally adaptive gene complexes. We have NO data suggesting that any of these populations was recently divergent and therefore likely has not developed locally adaptive gene complexes. We do however have PLENTY of data showing very long divergence time, which with mutation and natural selection, almost certainly has resulted in locally adaptive gene complexes.

Further, a bottlenecking event certainly could happen to drive the phenotypic variation seen in different populations, but given that these populations are large (e.g., even on the smallest of islands in Bocas del Toro, I have estimated the population to be well over 20,000 individuals), and have been going on for thousands of years (majority of pumilio populations for over 1,000 years, and tincs even longer), I think it's naive to say that populations would need genetic rescue. Clearly, if there were negative results to be seen from that bottlenecking event, they would have popped up by now.

There likely are populations that have been separated for less time (e.g., Bastimentos Cemetery and Salt Creek and Red Frog Beach), but phenotypic variation to such a degree (in both size and color) does not likely change so quickly.

OD seems to be a fairly logical reason not to mix separate populations, and for the capabilities within the hobby, better to err on the side of caution. If hobbyists had free access to sequencing machines, we would be able to determine what populations are similar enough to one another to mix and what ones are not (not only free access to sequencing machines, but the ability to look at a wide array of the genome). But neither of those criteria are happening.

There is only likely a very small number of populations out there that would not be subjected to OD if crossed. And like I said, without the ability to assess genetic similarity, it is better for the hobby to assume OD will happen than will not because once you make those crosses, there's no going back. If wrong, gene complexes will forever be lost within the hobby. I would say that OD is a very appropriate blanket statement.


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## ChrisK (Oct 28, 2008)

Something along these lines - would the Paru Sylvaticus be exhibiting any signs of outbreeding depression if they weren't a "real" morph but one "created" by Wikiri (I'm not suggesting this, just a curious scientific question) and if so, when would the signs be showing up?


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## BrianWI (Feb 4, 2012)

> It seems pretty obvious that, if you have two populations that look vastly different, that they are not subjected to the same environment.


So in each population, O. Pumilio all look the same because they are in the same environment? Or, conversely, the ones that are different from each other are in different environments? Bluff top populations of some frogs differ from other bluff top populations. Are the environments vastly different? If so, maybe you solved the whole mystery!

In the article, there was actually mention of species isolated for much longer than 500 years that also did not show OD. I do wish they had given a value to "high" and "low" probability. Being relative terms makes it unclear.



> OD seems to be a fairly logical reason not to mix separate populations, and for the capabilities within the hobby, better to err on the side of caution.


Erring on the side of caution is still error. In one discussion, it was said new manmade morphs would take away resources from other dart frogs in the hobby. Artificial separation would have a similar effect on resources.



> If wrong, gene complexes will forever be lost within the hobby.


Nonsense. One can keep both types. Just like one keeps GO/ regina separate. 


Gotta run!


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## BrianWI (Feb 4, 2012)

ChrisK said:


> Something along these lines - would the Paru Sylvaticus be exhibiting any signs of outbreeding depression if they weren't a "real" morph but one "created" by Wikiri (I'm not suggesting this, just a curious scientific question) and if so, when would the signs be showing up?


That would be hard to determine. F1? F5? Never? Hidden by inbreeding depression?


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## hypostatic (Apr 25, 2011)

Ed said:


> I don't know why it hasn't been taught in your classes since it has been known since the 1970s..


Oh, I'm not doubting that it's a real thing, but I guess my evolution classes focused mostly on speciation and driving factors behind it and the results, and not really what happens when two disjunct populations start breeding again. Well, maybe in the sense of what happens to the alleles, but I guess not in the sense of what happens to the organisms...



Ed said:


> In captive populations, one of the greatest risk comes from lines of animals that have been inbred over successive generations, and then outcrossed to animals either of wildly diverging lines or animals close to the wild populations. See for example (if I remember correctly) http://eliedolgin.com/pdfs/Evolution2007.pdf
> and Inbreeding Depression and Outbreeding Depression Are Evident in Wild-Type Zebrafish Lines
> 
> Some comments,
> ...


Ah, see, this is what I'm trying to wrap my head around. I'll read the papers when I get a chance. So crossing an azureus with another azureus in the hobby doesn't really pose a risk of depression, but crossing it with a wild caught azureus would have a higher probability of depression, correct?


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## Ed (Sep 19, 2004)

hypostatic said:


> Ah, see, this is what I'm trying to wrap my head around. I'll read the papers when I get a chance. So crossing an azureus with another azureus in the hobby doesn't really pose a risk of depression, but crossing it with a wild caught azureus would have a higher probability of depression, correct?


Keep in mind that we are considering the risk of occurance, so breeding fine spot azureus to fine spot azureus is very low risk as is wild caught or low F number to wild caught to low F number or regular captive bred azureus to regular captive bred azureus. The greatest risk of outbreeding would be to breed a highly inbred fine spot to a wild caught animal... 

In general when looking at captive populations, attempting to outcross an animals is a measure of last resort due to the risk (and how the public can percieve it (for an interesting point on public perception look at the boxer and dalmation outcrosses here The outcross that saved the Basset hound « The Retriever, Dog, & Wildlife Blog). 
I've posted it a lot on the forum but this gives a good evaluation of the relative risks.. http://dornsife.usc.edu/labs/edmands/documents/Edmands_2007.pdf 

One of the things that can make it even more complex is that it is possible in some rare cases to have both inbreeding and outbreeding depression occuring at the same time (see Cambridge Journals Online - Abstract) People weren't really looking for it in vertebrates until the late 1990s and early 2000s.


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## thedude (Nov 28, 2007)

BrianWI said:


> Nonsense. One can keep both types. Just like one keeps GO/ regina separate.


Not if the hobbies history has taught us anything. As I have told you several times before, There aren't enough hobbyists to keep the populations we already have going and in good shape. Why would we have room for hybrids? We have lost several morphs and populations over the years, and there are quite a few that fall out of favor constantly and you wind up with only a few people working with them. Bottlenecking is probably already a problem with some due to this. 

We don't have the resources to keep everything going with good management.


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## BrianWI (Feb 4, 2012)

thedude,

Then, as I said, you may be wasting resources keeping RO/ regina as separate lines! 



> The greatest risk of outbreeding would be to breed a highly inbred fine spot to a wild caught animal...


Yet, per the article, since this fine spot breeding has not been breeding separately for over 500 years, expected OD would be small.

The article does say that assuming OD will be present may not be correct.

It was argued by Ed and JP in another thread that they are managing our captive populations to maintain the genetic diversity and frequency of the wild populations by random matings. If they are so well-maintained, then obviously OD is NOT going to happen in such a case.


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## Golden State Mantellas (Mar 12, 2011)

Very interesting reading material.


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## Ed (Sep 19, 2004)

thedude said:


> There aren't enough hobbyists to keep the populations we already have going and in good shape.


I'm going to disagree with you here.. there are plenty of hobbyists so we could keep the populations here in good shape. The failure is that there aren't enough people interested in making the effort so only a few species may end up being managed for even a relatively short period. 

Some comments,

Ed


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## jacobi (Dec 15, 2010)

Ed said:


> I'm going to disagree with you here.. there are plenty of hobbyists so we could keep the populations here in good shape. The failure is that there aren't enough people interested in making the effort so only a few species may end up being managed for even a relatively short period.
> 
> Some comments,
> 
> Ed


But that would only work if they all had accurate records, correct?


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## Ed (Sep 19, 2004)

jacobi said:


> But that would only work if they all had accurate records, correct?


If I understand you correctly, no. For example if we look at the population of auratus that has been captive bred since the 80s, and started the management say at the end of the month, we would try to trace it back as far as we can (as it gives an idea of how well represented a animal is in the population), but for those without any data would be treated the same as those known animals since the goal is to try and sustain the level of genetic diversity at the moment management started. 

Ed


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## MonarchzMan (Oct 23, 2006)

BrianWI said:


> Yet, per the article, since this fine spot breeding has not been breeding separately for over 500 years, expected OD would be small.


Um, where did fine spots been breeding for less that 500 years come from?



> It was argued by Ed and JP in another thread that they are managing our captive populations to maintain the genetic diversity and frequency of the wild populations by random matings. If they are so well-maintained, then obviously OD is NOT going to happen in such a case.


If you actually bothered to read ANYTHING, you would have known right off the bat that what Ed and I argued was that captive populations COULD be managed to maintain genetic diversity without the need of wild caughts to occasionally supplement the population. This is done in zoos with all managed animals. But I also went on to note that the hobby is too disorganized to do such a thing at the moment.

Further, in this discussion, the risk of OD clearly is in reference to breeding DIFFERENT populations together. If a new import comes in tomorrow with Bastimentos cemetery frogs, they could be bred with captive BC frogs with little risk of OD.

Just because you don't understand any of the positions Ed or I take does not mean you can make up positions and say we said them so as to make your poor standing seem stronger.


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## thedude (Nov 28, 2007)

BrianWI said:


> thedude,
> 
> Then, as I said, you may be wasting resources keeping RO/ regina as separate lines!


and, as I've said several times, the reasoning behind mixing those 2 morphs has quite a bit of evidence behind it so yes you're right. However, this does not mean we should be mixing different localities. You completely missed my point, or blew it off. Not sure which. But saying the above to me as if I said they shouldn't be mixed is meaningless since I already said there was evidence for it. Again.

Just to be clear. Again.


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## BrianWI (Feb 4, 2012)

JP is confusing JP by jumping randomly from point to point without keeping up. I'll try to back track for you. But remember, there are other people talking at the same time so it might get you confused again. Any way, back a bit...

"So in each population, O. Pumilio all look the same because they are in the same environment? Or, conversely, the ones that are different from each other are in different environments? Bluff top populations of some frogs differ from other bluff top populations. Are the environments vastly different? If so, maybe you solved the whole mystery!

In the article, there was actually mention of species isolated for much longer than 500 years that also did not show OD. I do wish they had given a value to "high" and "low" probability. Being relative terms makes it unclear."

I am trying to figure out what you believe on these, start there.



> Um, where did fine spots been breeding for less that 500 years come from?


Then answer this... Are fine spots a different morph that should NOT be mixed with standard azureus and exist as an isolated population in the wild?

If they have only become a separate population in captivity, how long have they been linebred?

I hope you can keep on task and just answer these couple things. It hasn't gone well in the past, hopefully it will this time.


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## MonarchzMan (Oct 23, 2006)

BrianWI said:


> "So in each population, O. Pumilio all look the same because they are in the same environment? Or, conversely, the ones that are different from each other are in different environments? Bluff top populations of some frogs differ from other bluff top populations. Are the environments vastly different? If so, maybe you solved the whole mystery!


Same game, different players. When environments are similar, you find similar adaptations. This can be seen in a huge number of taxa. That there is a difference obviously means there is a difference in selective pressures being exerted on the population (random establishment of a phenotype is probably unlikely as the founding population likely was too big for such a novel phenotype to persist). The environments need only be different, they do not need to be vastly different. Something as simple as predator A being more abundant in population 1 and predator B being more abundant in population 2 can be all that is necessary to illicit selective pressure on one color over another.

But because two populations are similar does not mean they are because gene flow is high between them. It could be a number of possibilities, from common ancestry to independent origins.



> In the article, there was actually mention of species isolated for much longer than 500 years that also did not show OD. I do wish they had given a value to "high" and "low" probability. Being relative terms makes it unclear."


I don't know why you included this. Would you like me to read their minds or something?



> Then answer this... Are fine spots a different morph that should NOT be mixed with standard azureus and exist as an isolated population in the wild?
> 
> If they have only become a separate population in captivity, how long have they been linebred?


Hence the problem with descriptive names over subspecies or localities. I was thinking fine spot leucs. Ed covered this.



> I hope you can keep on task and just answer these couple things. It hasn't gone well in the past, hopefully it will this time.


Then I would suggest you address others' points rather than skipping over them.


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## thedude (Nov 28, 2007)

BrianWI said:


> Then answer this... Are fine spots a different morph that should NOT be mixed with standard azureus and exist as an isolated population in the wild?
> 
> If they have only become a separate population in captivity, how long have they been linebred?


When did we start talking about azureus? I thought we were talking about leucs...

With respects to the above about azureus though, these questions have already been answered. They are a different morph but that's because morph is about phenotype, not population. All the azureus are from the same population and SHOULD be mixed. The line breeding thing hasn't been going on for very long.

With the leucomelas on the other hand, the Bolivar (fine spots) are from a different area than the standards. Just as they are separate from the green foots, bandeds, blue foots, and the ones that look almost green.

This has all been answered though, so I don't know why it is still being questioned if they should be mixed.


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## BrianWI (Feb 4, 2012)

> Same game, different players. When environments are similar, you find similar adaptations. This can be seen in a huge number of taxa. That there is a difference obviously means there is a difference in selective pressures being exerted on the population (random establishment of a phenotype is probably unlikely as the founding population likely was too big for such a novel phenotype to persist). The environments need only be different, they do not need to be vastly different. Something as simple as predator A being more abundant in population 1 and predator B being more abundant in population 2 can be all that is necessary to illicit selective pressure on one color over another.
> 
> But because two populations are similar does not mean they are because gene flow is high between them. It could be a number of possibilities, from common ancestry to independent origins.


Ah, now we get somewhere. So, birds are the main predators. Talking bluff top populations near each other, the environment may be identical, yet no gene flow, and have very LOW probability of OD. Hence, locale as reported in an import may not be an indicator of OD risk.

However, the whole point og O. Pumilio research is why are there so many colors in the same environment. Kind of counters some ideas.



> Hence the problem with descriptive names over subspecies or localities. I was thinking fine spot leucs. Ed covered this.


I told you JP was confusing JP. 



> Then I would suggest you address others' points rather than skipping over them.


This is part of the issue with the cliqueness common on forums and certainly seen here. If you answer on eperson, the rest say you aren't answering them. If you answer them all, as you demonstrated, people become confused. These debates often become mob attacks, just another method of debating on other grounds besides fact. A bad one. For instance, if I debate you, Ed jumps in with something that drags us of topic, then you come back and do the same. Real answers never come. I understand that maybe some want to save another from their bad arguments, but it just gets confusing. Like saying gastropods aren't used to replicate human tissues, being proven wrong, then having someone else come in with a paper from an extreme animal rights activist. In the attempt to cover the bad argument, things get skewed all over.

I think this is what has come about with the idea of outbreeding depression. It has been given a place in debates without as much proof behind it as there should be. Instead, it remains an issue that is better explored on a case by case basis, rather than by "better safe than sorry" arguments. That answer doesn't hold water. Maybe two population would suffer, maybe they wouldn't. In any case, looking at the math as presented and some additional texts, the actual overall mathematical risk of OD is quite small. In my eyes, it is something worth actually testing.


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## BrianWI (Feb 4, 2012)

To keep this topic from going further south, I am going to call it CLOSED. I don't want to see it degraded as some already turned it from exploration of the topic to argument.

BYE!


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## Scott (Feb 17, 2004)

Of course Brian - you don't get to make that decision.

s


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## BrianWI (Feb 4, 2012)

Scott, actually, I do get to make that decision.

I simply won't read it anymore. I do get to flex my muscles a bit by using self control. No one can force me to read it


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## Scott (Feb 17, 2004)

Oh, you've shown _such_ self restraint in the past. 

Anyhow - topics are closed as needed by Moderators.

s


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## MonarchzMan (Oct 23, 2006)

BrianWI said:


> Ah, now we get somewhere. So, birds are the main predators. Talking bluff top populations near each other, the environment may be identical, yet no gene flow, and have very LOW probability of OD. Hence, locale as reported in an import may not be an indicator of OD risk.
> 
> However, the whole point og O. Pumilio research is why are there so many colors in the same environment. Kind of counters some ideas.


Birds are hypothesized to be the main predators, but predation events are rare, and there are actually more events of invertebrates preying upon the frogs than there are birds (the only one I can think of actually did not see the predation event, but reported a motmot picking up an auratus.

I have no idea what you are talking about with "bluff top" populations. Pumilio populations in Bocas have been separated for a minimum of 1000 years, with most older than that. Your assertion that there is low risk of OD is unfounded.

Pumilio research seeks to find what is _different_ between populations to figure out why there is such a variety of colors. It is inherent in the research that there are selective differences between populations. Selective pressures are far more than simply local environment.



> I told you JP was confusing JP.


No, you were being confusing, as evident that I was not the only one thinking leucs. You simply said fine spots, and I am not a mind reader, so I assumed that it was in reference to something that has not been clarified. You failed to specify azureus. If I started talking about banded frogs, you would have no idea if I was referencing leucs or intermedius. The fault would be mine for not being clear, like you were in reference to fine spots.



> This is part of the issue with the cliqueness common on forums and certainly seen here. If you answer on eperson, the rest say you aren't answering them. If you answer them all, as you demonstrated, people become confused. These debates often become mob attacks, just another method of debating on other grounds besides fact. A bad one. For instance, if I debate you, Ed jumps in with something that drags us of topic, then you come back and do the same. Real answers never come. I understand that maybe some want to save another from their bad arguments, but it just gets confusing. Like saying gastropods aren't used to replicate human tissues, being proven wrong, then having someone else come in with a paper from an extreme animal rights activist. In the attempt to cover the bad argument, things get skewed all over.


You have had not problem addressing everyone in the past. It should be no problem answering points bought up by people, especially when those points are repeated as they often are.



> I think this is what has come about with the idea of outbreeding depression. It has been given a place in debates without as much proof behind it as there should be. Instead, it remains an issue that is better explored on a case by case basis, rather than by "better safe than sorry" arguments. That answer doesn't hold water. Maybe two population would suffer, maybe they wouldn't. In any case, looking at the math as presented and some additional texts, the actual overall mathematical risk of OD is quite small. In my eyes, it is something worth actually testing.


You have not demonstrated that the benefits outweigh the risks. You suggest that perhaps a population needs genetic rescue, but you have not given any such population that could fit that criteria. Additionally, Ed and I have provided evidence that all of the populations of studied species are older than 500 years, so they would be at risk of OD if crossing separate populations together. All of the evidence provided points to the risk being greater than the benefit. Yes, there is the possibility that there are populations less than 500 years old that would have minimal risk of OD, but if they exist, they have not been discovered to be of such age, and until it is known, should be treated as if OD is a risk. Like I said, once you make and maintain such crosses and ruin those locally adaptive genes, there is no going back.

You are welcome to duck out, but we are still very much on topic. You're ducking out does not mean you are correct in your positions. There has been plenty of evidence provided that shows that crossing different populations clearly poses risk of OD. And for that reason, different populations should not be crossed.


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## BrianWI (Feb 4, 2012)

You don't like how things often degrade, then are critical of me when I try to prevent it? That seems odd. Still doesn't change the fact that I won't read it (only did because I saw a mod response), effectively closing the thread for my participation on the OT. I think it has been fairly valuable discussion, until the last few posts. If anyone else wants to continue it on, I would think the motive would be either to create a bad situation, or try to distort the original intention. Eh, not interested in participating in that. The posted studies agree with my conclusion, good enough for me. The other argument for me not proving what they never proved in the first place are actually not worth having. Neither side is proven, it just leans my way.

To me, CLOSED - Even for mod posts. I will have to be the bigger man.


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## mantisdragon91 (Jun 2, 2010)

BrianWI said:


> You don't like how things often degrade, then are critical of me when I try to prevent it? That seems odd. Still doesn't change the fact that I won't read it (only did because I saw a mod response), effectively closing the thread for my participation on the OT. I think it has been fairly valuable discussion, until the last few posts. If anyone else wants to continue it on, I would think the motive would be either to create a bad situation, or try to distort the original intention. Eh, not interested in participating in that. The posted studies agree with my conclusion, good enough for me. The other argument for me not proving what they never proved in the first place are actually not worth having. Neither side is proven, it just leans my way.
> 
> *To me, CLOSED - Even for mod posts. I will have to be the bigger man*.


If that was the case why keep posting twice more after your first declaration of leaving the thread?


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## Scott (Feb 17, 2004)

And, of course, my post was simply to inform you that _you_ can not close a thread. That's all.

No need to answer. 

s


BrianWI said:


> ... To me, CLOSED - Even for mod posts. I will have to be the bigger man.


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## MonarchzMan (Oct 23, 2006)

BrianWI said:


> The posted studies agree with my conclusion, good enough for me. The other argument for me not proving what they never proved in the first place are actually not worth having. Neither side is proven, it just leans my way.


Then elaborate since clearly everyone else reads it differently. I asked you simple clarification on your positions, so I fail to see how that makes this "go south." In the time you admonished me, you could have instead addressed my points.

And FYI, science doesn't prove anything. It is the concept of falsiability which is a central tenet in science (and why I say there could be populations that are less than 500 years old and would have minimal risk of OD). That neither side is proven is irrelevant as they will never be proven.


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## Brotherly Monkey (Jul 20, 2010)

MonarchzMan said:


> I have no idea what you are talking about with "bluff top" populations. Pumilio populations in Bocas have been separated for a minimum of 1000 years, with most older than that. Your assertion that there is low risk of OD is unfounded.


a bit OT: I'm assuming that dating is based on genetic research; If so, how is it actually established from that data?


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## MonarchzMan (Oct 23, 2006)

Brotherly Monkey said:


> a bit OT: I'm assuming that dating is based on genetic research; If so, how is it actually established from that data?


It is based off of the island age, actually, and historic sea level change. Ten thousand years ago, all of Bocas was land, and since then, the sea has been rising, and as recently as 1000 years ago, islands have separated.

I am hoping to do a more accurate test using genetic data. It wouldn't surprise me if some of the populations were actually older than the islands. That age is determined based off of a standard rate of mutation as well as calibration to geographic timelines. That is how the age of tinc populations were determined.


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## Ed (Sep 19, 2004)

BrianWI said:


> Ah, now we get somewhere. So, birds are the main predators. Talking bluff top populations near each other, the environment may be identical, yet no gene flow, and have very LOW probability of OD. Hence, locale as reported in an import may not be an indicator of OD risk.


Brian, 

In effect you are taking the following position, 

1) seperate populations of pumilio have the same color pattern

2) if seperate populations of pumilio have the same pattern, then the selection pressures on the populations must be the same

3) Pumilio from seperate populations with the same pattern are at low risk of out breeding depression. 

There are a lot of problems with this position, since it doesn't prove that the selective pressures are the same... and it has long been established that organisms occupying the same general habitat can be living under very different conditions.* We can in fact actually demonstrate that the populations aren't the same by looking at the alkaloid toxin profiles in the frogs... There is a huge difference both over time and distance, demonstrating that the enviroment isn't the same because the arthropods that supply the alkaloids differ over geography and time**. 


*(for example) (not free access) An Error Occurred Setting Your User Cookie 

**(free access available search title) ScienceDirect.com - Toxicon - Spatial and temporal patterns of alkaloid variation in the poison frog Oophaga pumilio in Costa Rica and Panama over 30 years


In addition, we can clearly see outbreeding depression occuring in anurans that are not known to be polymorphic (much less on the scale of O. pumilio.( see http://www.environmental-expert.com/Files\6063\articles\5372\LV68M29432114864.pdf) and have extremely similar patterns..... 

Oddly enough, a short review of the literature provides us with a robust documentation of data demonstrating the opposite point across multiple taxa.... 



BrianWI said:


> I think this is what has come about with the idea of outbreeding depression. It has been given a place in debates without as much proof behind it as there should be. Instead, it remains an issue that is better explored on a case by case basis, rather than by "better safe than sorry" arguments. That answer doesn't hold water. Maybe two population would suffer, maybe they wouldn't. In any case, looking at the math as presented and some additional texts, the actual overall mathematical risk of OD is quite small. In my eyes, it is something worth actually testing.


Brian, oddly enough, the vast majority of discussions on outbreeding depression have involved citations and references indicating the risk... could it be that you have an ulterior motive for making the argument that the crosses should be done? This seems very similar to other statments you've made around this topic for example (and there are others)..... 



BrianWI said:


> This is one reason I generally approve of creating new hybrids or morphs in captive breeding efforts. Desire for new morphs may take pressure of looking for new WC specimens.





BrianWI said:


> Why must your captive frogs match the wild populations?


 
Some comments

Ed


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## Scott (Feb 17, 2004)

Ulterior motives? Brian?!?

Say it ain't so Ed, *SAY IT AIN'T SO*!

On a calmer, more collected, thought - thank you for doing the research on this Ed.

s


Ed said:


> ... Brian, oddly enough, the vast majority of discussions on outbreeding depression have involved citations and references indicating the risk... could it be that you have an ulterior motive for making the argument that the crosses should be done? This seems very similar to other statments you've made around this topic for example (and there are others).....


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## Shinosuke (Aug 10, 2011)

BrianWI said:


> To keep this topic from going further south, I am going to call it CLOSED. I don't want to see it degraded as some already turned it from exploration of the topic to argument.
> 
> BYE!





BrianWI said:


> Scott, actually, I do get to make that decision.
> 
> I simply won't read it anymore. I do get to flex my muscles a bit by using self control. No one can force me to read it





BrianWI said:


> You don't like how things often degrade, then are critical of me when I try to prevent it? That seems odd. Still doesn't change the fact that I won't read it (only did because I saw a mod response), effectively closing the thread for my participation on the OT. I think it has been fairly valuable discussion, until the last few posts. If anyone else wants to continue it on, I would think the motive would be either to create a bad situation, or try to distort the original intention. Eh, not interested in participating in that. The posted studies agree with my conclusion, good enough for me. The other argument for me not proving what they never proved in the first place are actually not worth having. Neither side is proven, it just leans my way.
> 
> To me, CLOSED - Even for mod posts. I will have to be the bigger man.


Summation:

"Everyone disagrees with me so you must all be wrong. This is the final, definitive statement of the discussion and I now declare that no one may say anything else on the matter. If you discuss this further you are either deliberately trying to make trouble or slander me. Either way I'm right and I'm not interested in what you have to say, and any other topic in which anyone disagreed with me is not worth having because, regardless of experience or scientific proof, I'm still right. Oh, and I'm better than all of you."

.....

Sound about right?


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## cbreon (Apr 25, 2005)

Brian has continued his quest over on dart den, feel free to join in the fun:

Dart Den • View topic - Outbreeding Depression - Is it REALLY the issue?


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## MonarchzMan (Oct 23, 2006)

I've got no interest in twisting my words to suit his own goals. There are so many flaws to his argument that have been pointed out here that it really is an open and shut case. Simply logistically, performing crosses to determine if OD is a major threat to any population will require years of dedication and a great deal of space, and to what point and purpose? At the end of it, you'll have wasted all of those resources for a question that has already been answered in the literature. Why waste the time?

To be clear, I am very interested in dart frog genetics. What controls color? What controls spots? What controls the tie dye coloration of tincs? It is all quite interesting, but really, those aren't questions that a typical hobbyist can answer due to the logistic constraints as well as lack of resources. So leave the genetics to the geneticists. They're doing a pretty good job discovering these things. If you are particularly interested in a question, advocate for research to be done in that area. Find a scientist who is interested and has the means to answer the questions rather than skimming the surface which has been suggested here. Donate time, money, or frogs to that scientist so that his/her job may be easier to answer the question.


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## edwardsatc (Feb 17, 2004)

Shinosuke said:


> Summation:
> 
> "Everyone disagrees with me so you must all be wrong. This is the final, definitive statement of the discussion and I now declare that no one may say anything else on the matter. If you discuss this further you are either deliberately trying to make trouble or slander me. Either way I'm right and I'm not interested in what you have to say, and any other topic in which anyone disagreed with me is not worth having because, regardless of experience or scientific proof, I'm still right. Oh, and I'm better than all of you."
> 
> ...


You forgot:

"I'm smarter than you." 

"I'm bigger and tougher than you."

"My daddy can beat up your daddy."


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## Pumilo (Sep 4, 2010)

C'mon guys! All you have to do is look at the vast experience he has breeding dart frogs to know that he is always right and we will always be wrong.


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