Link doesn't work. If you're outside the edit window, post it and I'll edit it in above.

 

Looks to be working now, thanks!

 

The spotting and blue coloration on that specimen doesn't look to be an azureus to me but more inline with sipaliwini characteristics. However, identifying frog morphs/locaels by visual phenotype alone is very unreliable.

I'm not a biologist so someone correct me if I'm wrong. As I understand it the species is the same,so unless there are genetic characteristics that seperate locaels this would not be the classic azureus, since it was collected outside the established locael of the azureus.

 

The spotting and blue coloration on that specimen doesn't look to be an azureus to me but more inline with sipaliwini characteristics. However, identifying frog morphs/locaels by visual phenotype alone is very unreliable.

I'm not a biologist so someone correct me if I'm wrong. As I understand it the species is the same,so unless there are genetic characteristics that separate locales this would not be the classic azureus, since it was collected outside the established locale of the azureus.

Sure I could see that but blue sips are also from Suriname and thought to be restricted there. Azures, blue sips, and green sips are all thought to be remnants of a once larger population that became fragmented as the savanna expanded and isolated forest patches. There is some possible genetic evidence for these population gaining contact for a period after being isolated but that's besides the point.

There are genetic differences between dart frog species locales that give rise to difference in appearance between locales. It not like atelopus or somthing where thes varations are a result of polymorphism. Dart frogs locales are a result of convergent evolution.

It could be "the classic azureues" as in more closely related to the population of blue tincs described by Hoogmoed 1969, than to nearby populations of tintorious. If as @themountainsaid they wre introduced by humans.It could also be that the population of blue color dominate tincs was larger then we understood, prior to the expanstion of the savanha.

 

Maybe they were artificially introduced to facilitate export?

 

"Only blue Tinctorius variants are known from British Guiana" (that is, 'Guyana', since 1966).

Morphguide - die einzelnen Varianten

Also, check out the data (no photo, unfortunately) on specimen #22, which -- if I'm reading correctly -- is most closely related to the Sipaliwini samples and was collected ~2 miles from the Essequibo and maybe 10 miles from the headwaters:

https://www.researchgate.net/publication/6691239_Refugial_isolation_and_secondary_contact_in_the_dyeing_poison_frog_Dendrobates_tinctorius

 

Wow. You're amazing!

So blue tincs from this region were already known of. Just not by me

If only they had an image of #22.

Frog 22 appears to be most closely related to Frog 18 (Tafelberg, Suriname).

Frogs 17 is the "Azureus". It is most closely related to Frog 23 (Sipaliwini) and Frog 15 (Ellerts de Haan, Suriname) .

 

So if frog 22 was indeed representative of the blue colored tincs as seen in the documentary, we can assume this is a case of convergent evolution, as frog 17 and Frog 22 were not closely related?

 

I'm not sure that coloration is necessarily, or even often, an example of convergent evolution. I'm under the impression that to establish that we'd need to establish that the specific coloration -- in this case, blue, and maybe the pattern also -- is adaptive in similar environmental conditions in each case but that the coloration/pattern didn't descend from an ancestor common to both.

Is the coloration of tinc locales adaptive? I don't know myself.

 

We do know that convergent evolution of crypsis (camouflage) coloration and pattern is common, but for aposematic coloration and patterning, this might be less well understood because aposematic mimicry makes things more complex to tease apart.

At least some (perhaps most?) of the color and pattern variations observed between dart frog locales can be attributed to allopatric separation, where geographic isolation reduces gene flow, enabling phenotypic divergence via genetic drift or founder effects.

However, selective pressures could lead to convergence on particular color and pattern variations.

Multiple unrelated dart frog species, as well as the black-eared mantella (Mantella milotympanum), have independently evolved predominantly red coloration, despite not being closely related. The study Multiple Routes to Color Convergence in a Radiation of Neotropical Poison Frogs suggests that similar coloration in Ranitomeya species is the result of convergent evolution, implying that coloration in dart frog locales is adaptive rather than a purely neutral trait. At least I believe the paper support that, it takes me a while to read papers.

Regarding blue coloration in D. tinctorius, blue coloration is already known from multiple populations in the Eastern haplogroup, including Azureus (Vier Gebroeders) and blue sips (Sipaliwini). Genetic data indicates these populations are closely related, meaning they likely inherited their blue coloration from a common ancestor. However, Frog 22 (Acarai) belongs to the Western haplogroup. If it is also blue, this trait would have either evolved separately (convergent evolution) or been retained from an ancestral population that carried both blue and non-blue individuals.

Given the lack of phenotypic plasticity or polymorphism in dart frog locales today, I find the ancestral polymorphism hypothesis less likely.

Since Western haplogroup frogs like Tafelberg are not known to be blue, I feel that the case for convergent evolution in Acarai remains somewhat strong.

I am a bit puzzled by the difference in appearance between this frog,

presented as D.tinc. 'British Guyana' in the morphguide and the frog see in the documenry.

 

similar coloration in Ranitomeya species is the result of convergent evolution, implying that coloration in dart frog locales is adaptive rather than a purely neutral trait.

I think the R species that are mimics are a special case, which maybe shouldn't be taken to imply anything universal about the adaptive benefit of locale-distinct dart frog coloration. I mean, tincs don't use mimicry AFAIK, so wouldn't have that adaptive pressure (i.e. to mimic lest they get outcompeted by those that do).

Yes, I agree about the difference between the frog in the video and the photo above, but they're both black on blue and possibly separated by quite some distance. I didn't actually watch the video except to see the frog at the time stamped spot you mentioned; is there any reasonably specific location data/info given?

 

I think the R species that are mimics are a special case, which maybe shouldn't be taken to imply anything universal about the adaptive benefit of locale-distinct dart frog coloration.

I agree. This is what I was talking about when I wrote,

for aposematic coloration and patterning, this might be less well understood because aposematic mimicry makes things more complex to tease apart.

There are lots of examples of similar aposomatic colors/patters across distantly related taxa. Cases where no one would suggest mimicry was involved. If the difference between locale-distinct dart frog coloration is not adaptive (driven by selective pressure) then it is odd that locales are so "true breeding" (ie color variation is not likely a result of polymorphism or other phenotypic plasticity). Im just not sure genetic drift alone could explain what we see. If drift were the only factor, we might expect more unstable variation rather than the high-fidelity inheritance of distinct local morphs. This suggests that some form of selection, whether natural selection (predation) or sexual selection (mate choice) is likely shaping these color patterns.

This paper indicates that genes realted to color variation in locales of O. pumilio are udner selective pressure,
Being red, blue and green: the genetic basis of coloration differences in the strawberry poison frog (Oophaga pumilio)

In addition to regulatory differences, we found potential evidence of differential selection acting at the protein sequence level in several color-associated loci, which could contribute to the color polymorphism.

They location was described as Guyana. Between Camp Martin and the source of the Essequibo river in the foothills of the Acari mountains.
location