First fluorescent frog found

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First fluorescent frog found

Postby Ilian Velikov » Thu Jan 18, 2018 10:57 am

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Re: First fluorescent frog found

Postby Michal Szkudlarek » Thu Jan 18, 2018 12:17 pm

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Re: First fluorescent frog found

Postby Ruggero Morimando » Thu Jan 18, 2018 12:22 pm




I think that sometimes researchers have time to spend in unuseful researches...
As dermatologist I use Uv lights to detect ringworm infections in a dark room. What is the finality of skin fungal infections to be fluorescent? To be better detected by dermatologists? :lol:

What is the finality of the fluorescence of a frog, which should normally avoid predators? And what the finality of its fluorescence if fluorescence is visible only at night if you have a Uv light?
I would say no finality: simply casual "byproducts" of evolution... pure fortuity...

Have you never seen in a disco how many things and clothes are fluorescent with Uv emitting lights?
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Re: First fluorescent frog found

Postby Guillaume Gomard » Thu Jan 18, 2018 9:57 pm

Ruggero Morimando wrote:What is the finality of the fluorescence of a frog, which should normally avoid predators? And what the finality of its fluorescence if fluorescence is visible only at night if you have a Uv light?
I would say no finality: simply casual "byproducts" of evolution... pure fortuity...


Agreed, even the studies citing the one discussed here go in the same direction:

"this kind of fluorescence does not seem to be relevant from a biological point of view and instead may be more likely interpreted as a byproduct of the chemical nature of certain pigments presents in the cells." (DOI: 10.2994/SAJH-D-17-00029.1)

It's just convenient to spot frogs in the rain forest, a good trick to use next time I will be in Central America ;)
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Re: First fluorescent frog found

Postby Berislav Horvatic » Fri Jan 19, 2018 12:19 am

Guillaume Gomard wrote:It's just convenient to spot frogs in the rain forest, a good trick to use next time
I will be in Central America ;)

Yeah, God really likes and supports fieldherpers, and offers them his creations, even
the "weird" ones, to their advantage... So use it, before He changes His mind... One
never knows...
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Re: First fluorescent frog found

Postby Ilian Velikov » Fri Jan 19, 2018 9:54 am

Ruggero Morimando wrote:I would say no finality: simply casual "byproducts" of evolution... pure fortuity...

Maybe...or maybe not. I don't know the answer to this but I know that whenever people fail to understand or explain anything they tend to say it's either irrelevant, coincidence or has no purpose, like the apendix in our bodies (which function was actually recently discovered). However, this of course doesn't mean they are right and I wouldn't approach anything unknown with such certainty.

Ruggero Morimando wrote:And what the finality of its fluorescence if fluorescence is visible only at night if you have a Uv light?

We do have UV light everywhere around us all the time, we humans just can't see it (as well as other lengths of light) without equipment. However, there are a lot of creatures that do, so let's not jump to conclusions. By the same logic one might ask what's the use of pheromones since we humans can't or have lost the ability to detect them?

So Berislav is right to be sarcastic about this rather "religious" approach to live in which everything should serve a purpose to humans, or at least one that they understand.
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Re: First fluorescent frog found

Postby Jeroen Speybroeck » Fri Jan 19, 2018 1:02 pm

In any case, it's a pretty frog. ;) Allow me to recycle two shots from our trip to Peru in 2013
(trip report - https://www.hylawerkgroep.be/jeroen/index.php?id=69)

Image

Image
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Re: First fluorescent frog found

Postby Guillaume Gomard » Fri Jan 19, 2018 1:23 pm

Ilian Velikov wrote:So Berislav is right to be sarcastic about this rather "religious" approach to live in which everything should serve a purpose to humans, or at least one that they understand.


Well, nobody claimed that everything should serve a purpose to humans (I wrote that it is something that could facilitate spotting some frogs in the forest at night, just like some do with invertebrates in the desert using a UV lamp, nothing more).

I was just skeptical about the excitation of the fluorophores in natural and crepuscular/night conditions (Ruggero probably had the same concern). Since I went through the article too rapidly the first time, I read it more carefully and found this : "...we estimated the contribution of fluorescence to the total emerging light under twilight, moonlight, and moonless night irradiances (21). Given our results and the ambient irradiance distribution, our calculations show that fluorescence contributes from 18.5 ± 2.6% in a full moon night to 29.6 ± 3.2% during twilight" (note that the reflectance is quite low so the absolute amount of converted light can still be pretty low). Next question is of course about the sensitivity of the frogs at 510nm...

@Jeroen: Lovely specimens!
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Re: First fluorescent frog found

Postby Ruggero Morimando » Fri Jan 19, 2018 1:51 pm

Ilian Velikov wrote:
Ruggero Morimando wrote:I would say no finality: simply casual "byproducts" of evolution... pure fortuity...

Maybe...or maybe not. I don't know the answer to this but I know that whenever people fail to understand or explain anything they tend to say it's either irrelevant, coincidence or has no purpose, like the apendix in our bodies (which function was actually recently discovered). However, this of course doesn't mean they are right and I wouldn't approach anything unknown with such certainty.

Ruggero Morimando wrote:And what the finality of its fluorescence if fluorescence is visible only at night if you have a Uv light?

We do have UV light everywhere around us all the time, we humans just can't see it (as well as other lengths of light) without equipment. However, there are a lot of creatures that do, so let's not jump to conclusions. By the same logic one might ask what's the use of pheromones since we humans can't or have lost the ability to detect them?

So Berislav is right to be sarcastic about this rather "religious" approach to live in which everything should serve a purpose to humans, or at least one that they understand.


Ilian, you are right, but you probably already know that I'm always a bit provocative in my judgments.
I wanted only to underline that in nature are present so many flourescent organisms and things (patogenic ifae were just an example), that finding another one just does not mean we have found something special or for sure "finalistic".
Having said that, the ancient wise men of Rome used to say "affirmanti incumbit probatio": so we all should now demonstrate that during some nights a sufficient amount of Uv light is still present to elicit frog skin fluorescence. Then, that this faint fluorescence, if present, is visible (probably only in the dark) from other frogs of the same species or from other animals in general. Then, try to find out the actual function of this "visible" (if visible) fluorescence...
Not so complicated as to demonstrate God's or Gods' (plural) existence, but still not an easy task... ;)
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Re: First fluorescent frog found

Postby Berislav Horvatic » Fri Jan 19, 2018 4:29 pm

Ruggero Morimando wrote:Not so complicated as to demonstrate God's or Gods' (plural) existence, but still not an easy task... ;)

God’s (or Gods’) existence can not be proved (or disproved, either) - at least, noone has ever succeeded,
much as they tried, the best minds of humankind, for two millenia... Of course, "affirmanti incumbit
probatio
", but it has never worked, either way.
For the Holy Church, the essential question is not whether God EXISTS, but whether you BELIEVE that He
exists. And that has nothing to do with science and the scientific methodology.
Pardon me for this off- topic.
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