Why are corals so brightly colored ?

[Arkalen]

So there are these creationists I'm talking to and one brought up how
Acropora corals are brightly colored, and why would that be, wouldn't
that make them vulnerable to predators ?

So looking it up it seems the main predators in question are flatworms
and sea snails, not sure how much Acropora have to hear from those
hawk-eyed killers... but I'm not seeing many positive reasons they might
be brightly colored either. Mating ? I don't think they have eyes.
Poisonous ? If their main predators are flatworms and sea snails... I
don't even know much what corals do in life. Grow and leech off their
algae friends like lichens I guess ? The color could also be a random
algae color but even plants are rarely brightly colored for random
reasons alone.

Does anyone here know a lot about corals ? Or is much more skilled at
Google than I am ?

[chris thompson]

Most corals are symbiotic with some sort of photosynthetic algae. The
colors you see are the photosynthetic pigments.

See:

http://en.wikipedia.org/wiki/Zooxanthellae

Chris

[Glenn]

On Jun 23, 9:17 pm, chris thompson <chris.linthomp...@gmail.com>
wrote:

I thought it was the coral itself, algae usually only a brownish base
color.

[Arkalen]

From what I could find out, Acropora in particular are usually
green-grey in color, but are occasionally bright red in the tropics. I
do think that was because of the zooxanthellae, but I'm still not clear
on why the algae themselves would be brightly colored. Is it to aid
photosynthesis, some other advantage of the pigments that's unrelated to
their color, or is the color itself adaptive for some reason ?

[Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org]

If - since - they're symbiotic with the coral
(where they live), if the colour was
disadvantageous to the coral then it would
be disadvantageous to the algae, I suppose.

But the alleged predators may not have colour
vision (?), and there's also that thing of
brightly coloured prey being bad to eat.

By the way, wouldn't Noah's flood have
exterminated coral? (and freshwater fish
of course).

[Frank J]

It's good that you asked biologists. But did you ask those "creationists" what their explanation was? Not the "Goddidit" part, which many "evolutionists" agree with but the all important "how and when" part? Did you even find out what "kind" of creatonists they were? Since you used the plural, were they even all the same "kind" - e.g. geocentric YEC, old-earth-young-life, old-earth-old-life? Did they concede common descent like Behe? Or might they have internal disagreements that they're either unaware of or deliberately covering up?

As you know, if you answer "creationist" questions without devoting at least equal time to asking about their "theories" you are helping them to spin more bogus incredulity arguments to other audiences, while letting them off the hook from questions that they can't, or don't want to, answer.

[Frank J]

No, but there are about a million questions that one could ask those who truly believe that there is evidence of a global flood that extinguished nearly all life ~4K years ago. The worst thing to do is assume that any evolution denier believes that, much less that they believe it happened on a planet that was only a few 1000 years old a the time. If they respond by admitting that they doubt the flood story too, the egg on one's face is hard to remove.

[chris thompson]

It's generally the algae that's pigmented, and yes, it's to perform
photosynthesis. The algae are generally more sensitive to pollution
than the corals and die earlier. That's why it's such a bad sign when
a coral reef goes white.

Chris

[chris thompson]

Algae come in all colors. Classically, they were divided up into the
brown algae (the kind that forms the giant kelp beds), green algae,
red algae (of red tide fame, although not all of them cause the
harmful blooms), blue-green algae (which are now classified as a type
of bacteria), and golden algae (the diatoms and others). This
classification has undergone massive revision, but you get the idea.

Chris

[Arkalen]

I'm asking the question because I'm interested in the answer, the
creationist in question is impervious to evidence. If I got an answer I
might pass it on to inform possible lurkers, or more likely I wouldn't
because the thread in question is dead. This post is for my own personal
curiosity.

[Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org]

----
One doesn't assume, but the YEC pigeon-chess
player kind of has to play the Flood Defence
against the Geologic Column.

[Ron O]

Plants have helper pigment molecules that transfer energy from light
and not just chlorophyll.

QUOTE:
Secondary Pigments

Photosynthetic cells also contain secondary, or accessory, pigments,
which absorb light where chlorophyll is not as useful. There are two
types of secondary pigments: carotenoids and phycobilins. All
carotenoids have 40 carbons and absorb in the range of 400 to 500 nm.
That is why their colors are red, orange, and yellow. Two categories
that represent carotenoids are xanthophylls and beta-carotenes.
Phycobilins absorb in the range of 550 to 630 nm
END QUOTE:

http://chemwiki.ucdavis.edu/Biological_Chemistry/Photosynthesis/Photosynthesis_overview#Secondary_Pigments

These are the pigments responsible for fall colors and red algae, etc.

Ron Okimoto

[Richard Norman]

The source you want is "The role of host-based color and fluorescent
pigments in photoprotection and in reducing bleaching stress in
corals" by Salih, Cox, et al.
http://www.coralcoe.org.au/research/publications/Salih_ICRS_2006.pdf

which says

Coral tissue colors result from both the intracellular symbiotic
dinoflagellates and the host’s own cellular pigments. The brownish
colors are due to the symbionts’ photosynthetic pigments; the bright
purple-blue and fluorescent colors are produced by the coral host and
are proteins closely related to Green Fluorescent Protein (GFP). One
of the documented biological functions of GFP-like pigments in corals
is light optimization. When light is excessive, GFPs reduce symbionts’
photoinhibition and photo-damage to coral’s tissues. Here we explored
further the ecological roles of coral coloration...These results
further substantiate earlier findings that GFP-like pigments reduce
photoinhibition and the severity of bleaching-related physiological
damage of corals.


There is also "Pigmentation as a strategy for reducing solar damage in
reef-building corals" by Kluter (2003)
http://espace.library.uq.edu.au/view/UQ:251950

whcih says

Reef-building corals are renown for their striking pigmentation. Many
coral pigments have been identified as homologs of the Green
Fluorescent Protein (GFP) of the Hydrozoan jellyfish Aequorea
victoria, yet little is known about their possible biological
function. Coral pigments are thought to have a role in the
photobiology of symbiotic corals, by both reducing and enhancing the
amount of light captured by symbiotic dinoflagellates. This thesis
explored the ecological significance of GFP-homologs in reef-building
corals, particularly those that are green fluorescent. It presents the
first comprehensive data set on spatial distribution patterns of these
pigments in reef-building corals. Moreover, it investigates how their
abundance is linked to their environment and the presence of other
pigments such as mycosporine-like amino acids (MAAs) and peridinin
that are known to regulate light stress in coral-algae associations.

Understanding the function of compounds associated with the
photobiology of coral symbiosis is integral to evaluate the full
impact of their ability to protect shallow water corals and hence how
these corals survive successfully in an extreme environment. The light
absorbing properties of corals and their interaction with solar
radiation is of a complex nature, which makes it often difficult to
gain a complete understanding of how these elements have interacted in
an ecological and evolutionary setting. This thesis however, indicates
that host pigments may play a major role of in regulating the solar
flux that reaches the dinoflagellate partner of the coral-algal
association. By regulating this flux in both, ultraviolet and
photosynthetically active spectra, host pigments show the potential to
be a critical element in determining how and where corals are found
within the extreme light gradients that are characteristic for the
shallow tropical sea that they inhabit.

[Frank J]

For my own personal curiosity:

I'm very aware that evolution-deniers who prefer to debate than learn are impervious to evidence. My interest in you asking them questions is not to change their minds or make them aware of their faulty knowledge and logic -though that does happen sometimes, so it's always worth a shot. But rather to, as you say, inform lurkers of creationist double standards and other word games. So did you ask?

Also, were there more than one creationist as you suggest in the first post but not in the 2nd? That too is for my curiousity, because, as you might have noticed, the typical "debate" thread has several "evolutionists," often challenging each other as well as the denier. But generally there's only one main evolution-denier in any thread. Others may participate to "cheerlead" but almost never dare challenge the "alpha dog," even if they disagree as much as Behe (accepts 4 billion years of common descent) and Pagano (geocentrist).

[Arkalen]

I agree with you on principle, but in practice I'll take different
approaches depending on context. And in that case it's a creationist
forum (mostly YEC, some OEC, and some atypical) and my main objective
there is to give factual information on evolution and science, hoping
they might reach those who are still light on the "willfully" in
"willfully ignorant". I try to keep the focus of each conversation as
specific as I can otherwise I get drawn into the most annoying and
frustrating of rabbitholes. I am perfectly fine with having the burden
of explaining things on me, seeing as that's what I'm going there for.

I do see the value of challenging them on their own beliefs, but I
prefer to do that when I've got specific reason to do so; as I said,
annoying rabbitholes. And while we agree that YEC beliefs aren't
rigorous at all and that asking a few questions makes it clear, it also
seems to me most YEC who hold such beliefs don't realize that they
*should* be rigorous, or that they *could*. Their ideas of science are
usually extremely vague and cherry-picked. So I figure if I give them a
more accurate picture of science, making points about how scientific
statements are justified and how precise they are, I can then show how
significant it is that YEC beliefs are completely vague and ad-hoc in
comparison.

>
> Also, were there more than one creationist as you suggest in the first post but not in the 2nd? That too is for my curiousity, because, as you might have noticed, the typical "debate" thread has several "evolutionists," often challenging each other as well as the denier. But generally there's only one main evolution-denier in any thread. Others may participate to "cheerlead" but almost never dare challenge the "alpha dog," even if they disagree as much as Behe (accepts 4 billion years of common descent) and Pagano (geocentrist).
>

There was one who started the post who seemed to be sincerely asking a
question on how this or that could have evolved and who I was responding
to in the thread, and a few regulars who were interjecting some "this
disproves evolution !" posts that I ignored. I ended up addressing their
claims in my conversation with the OP, but the corals guy is one of said
regulars who came back to the party some days after it was over. I'm in
two minds about responding; with Richard's info I can make it a short,
factual sentence which is fairly straightforward, but there's a reason I
was ignoring those guys in the first place. But I won't derail a thread
that was answering one poster's questions with a challenge to a hardened
creationist on their own beliefs.

[Arkalen]

Thank you very much Richard, that is fascinating and completely awesome!
Talk.origins comes through yet again ^^
Thank you also to the all the others who responded.

[wiki trix]

On Jun 24, 6:39 am, "Robert Carnegie: Fnord: cc talk-

I think that both freshwater and saltwater species would be equally
harmed. Perhaps Noah had to take several aquariums on board the ark to
keep all those aquatic species safe. Or perhaps there were some
postdiluvian creation activities that ended up on the biblical cutting
room floor, which we have no information on now. After all, the great
advantage of creationism as a theory is that absolutely any scenario
you can imagine is of equal plausibility. The creator is *that*
powerful!

[Frank J]

Your decision not to derail the thread reminds me of how we "Darwinists" heed the advice of that guy long ago who said to "turn the other cheek" (maybe too much, IMO) while anti-evolution activists violate it constantly.

I have to also reiterate my suspicion of self-proclaimed (inferred?) YECs. AIUI, before creationism became full-blown pseudoscience in the mid 20th century, most evolution-deniers who had given some thought to the evidence were OECs. Even ignoring the much greater evidence for the old-earth-old-life chronology (YECs and OECs are impervious anyway, as you say) deniers nowadays have more theological arguments to make the chronology, and even common descent, if not natural selection, much less threatening. OTOH we now have the big tent strategy. Which means that, while fewer than ever people *believe* YEC (a strongly worded poll puts it at only 20% of the population), a much greater % than ever are *politically* sympathetic to it. Which means they will refuse to criticize it, and maybe use some of its arguments (e.g. radio"carbon" dating) if it helps their case against evolution.

As for "challenging hardened creationists" on their *belief*, here's my 2c: I won't challenge their belief of a Creator because I can't (I can't challenge atheists either). I won't even challenge their belief of a flat earth, separate origin of humans and broccoli, etc., provided they admit, as some have to me, that there's no evidence and that they just take it on faith. I will challenge them, however, if they imply that 99+% of scientists who work in relevant fields, and who have the most to gain by falsifying evolution, are either wrong or "conspiring to expel."

[ed wolf]

"bright red" is a common camouflage color under water, after some 10-14m there is no red light, and "red" becomes "black", or rather "dark"( except in the divers`s flashlight). OTOH I have seen bright red coral in shallow water, so this does not really explain it. Maybe som marine organism do not even have eyesight for red light?
regards
ed

[Arkalen]

That's nice. But it's my time, my brainspace, my decisions. I have seen
you make these suggestions repeatedly, and I think they have a lot of
merit. I have taken them on board, as I do every time you bring them up.
I don't know what more you're expecting.

>
> I have to also reiterate my suspicion of self-proclaimed (inferred?) YECs. AIUI, before creationism became full-blown pseudoscience in the mid
20th century, most evolution-deniers who had given some thought to the
evidence were OECs. Even ignoring the much greater evidence for the
old-earth-old-life chronology (YECs and OECs are impervious anyway, as
you say) deniers nowadays have more theological arguments to make the
chronology, and even common descent, if not natural selection, much less
threatening. OTOH we now have the big tent strategy. Which means that,
while fewer than ever people *believe* YEC (a strongly worded poll puts
it at only 20% of the population), a much greater % than ever are
*politically* sympathetic to it. Which means they will refuse to
criticize it, and maybe use some of its arguments (e.g. radio"carbon"
dating) if it helps their case against evolution.

The forum in question clearly caters to the 20%. As for those who are
sympathetic to YEC without actually believing it, showing the flaws in
it is great but I think educating people about the science is great too.

> As for "challenging hardened creationists" on their *belief*, here's my 2c: I won't challenge their belief of a Creator because I can't (I can't challenge atheists either). I won't even challenge their belief of a flat earth, separate origin of humans and broccoli, etc., provided they admit, as some have to me, that there's no evidence and that they just take it on faith. I will challenge them, however, if they imply that 99+% of scientists who work in relevant fields, and who have the most to gain by falsifying evolution, are either wrong or "conspiring to expel."
>

I agree.

[Metspitzer]

On Sun, 24 Jun 2012 12:01:18 -0700 (PDT), Frank J <fc...@verizon.net>

How about a link to the other group where this is being discussed? My
Google skills came up blank.

http://groups.google.com/groups?as_q=Acropora+corals+are+brightly+colored&num=50&as_scoring=d&hl=en&as_epq=&as_oq=&as_eq=&as_ugroup=&as_usubject=&as_uauthors=&as_umsgid=&lr=&as_drrb=q&as_qdr=&as_mind=12&as_minm=5&as_miny=1981&as_maxd=20&as_maxm=2&as_maxy=2005&safe=off&sitesearch=&scoring=d

[Arkalen]

It's not a newsgroup, it's a small internet forum. Google "evolution
fairytale" if you're really interested but you won't see much - as I
said it's just something someone brought up on an old thread, there
isn't a lively conversation happening on the subject of corals or anything.

[Glenn]

On Jun 24, 5:05 am, chris thompson <chris.linthomp...@gmail.com>

I was referring to the algae associated with coral, in response to
your claim that algae are responsible for the various colors of coral.
Are you sure that these colors are produced by the zoox and not the
corals themselves?

[Richard Norman]

On Sun, 24 Jun 2012 13:09:59 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

I covered that in a separate post. Symbiotic algae in coral are
dinoflagellates which produce a brownish color. The bright colors are
produced by the coral.

[wiki trix]

Nope. Intrinsic color of coral is white. See: http://en.wikipedia.org/wiki/Coral_bleaching:
"Coral bleaching is the loss of intracellular endosymbionts
(Symbiodinium, also known as zooxanthellae) through either expulsion
or loss of algal pigmentation."

[Metspitzer]

Ok
Thanks

[Arkalen]

Yeah, I'd thought of that too, but then I figured 10-14m deep where
there is no red light anymore isn't the best place for photosynthesis :)
(if you haven't seen it I suggest you look at Richard Norman's reply to
me, I think he's got the goods)

[Glenn]

On Jun 24, 1:38 pm, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Sun, 24 Jun 2012 13:09:59 -0700 (PDT), Glenn <GlennShel...@msn.com>

It appears either you or Chris is wrong. But maybe neither. Is this
symbiotic relationship the means by which the algae provide the means
for coral to produce certain pigments?

[Richard Norman]

On Sun, 24 Jun 2012 13:52:44 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

Several people here have speculated about the pigments knowing that
different varietires of "algae" produce a wide variety of pigments of
different colors. I cited scientific paperss from authors who have
actually looked into the facts. The symbiotic algae produce some
colors. The coral, themselves, produce the bright colors and,
especially, ther fluorescent colors.

Of course the algae provide nutrition for the coral if that is what
you mean by "the means." They don't provide the biochemical routes
for synthesis.

[Glenn]

I always thought that white coral was the calcium carbonate skeleton
of dead coral colonies.

Are you familiar with the subject?

[Glenn]

On Jun 24, 2:01 pm, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Sun, 24 Jun 2012 13:52:44 -0700 (PDT), Glenn <GlennShel...@msn.com>

The second is what I wondered about, and seems to put a lock on the
controversy.

[Glenn]

> http://chemwiki.ucdavis.edu/Biological_Chemistry/Photosynthesis/Photo...

>
> These are the pigments responsible for fall colors and red algae, etc.
>

I'm not sure what it is you are responding to.

[Frank J]

[Frank J]

I suspect (not assume) that most OEC PCPs would do the same. ID peddlers (aka "big tenters") however, know better than to go down that road, even where it's legal.

[Frank J]

On Sunday, June 24, 2012 3:48:34 PM UTC-4, Arkalen wrote:

(sorry for duplicate, still getting used to the new GG)

I'm only expecting new readers to read what have they not likely read before. If that makes even one person ask polite questions instead of "you're lying for Jesus!" it's worth it.

>
> >
> > I have to also reiterate my suspicion of self-proclaimed (inferred?) YECs. AIUI, before creationism became full-blown pseudoscience in the mid
> 20th century, most evolution-deniers who had given some thought to the
> evidence were OECs. Even ignoring the much greater evidence for the
> old-earth-old-life chronology (YECs and OECs are impervious anyway, as
> you say) deniers nowadays have more theological arguments to make the
> chronology, and even common descent, if not natural selection, much less
> threatening. OTOH we now have the big tent strategy. Which means that,
> while fewer than ever people *believe* YEC (a strongly worded poll puts
> it at only 20% of the population), a much greater % than ever are
> *politically* sympathetic to it. Which means they will refuse to
> criticize it, and maybe use some of its arguments (e.g. radio"carbon"
> dating) if it helps their case against evolution.
>
> The forum in question clearly caters to the 20%. As for those who are
> sympathetic to YEC without actually believing it, showing the flaws in
> it is great but I think educating people about the science is great too.
>
> > As for "challenging hardened creationists" on their *belief*, here's my 2c: I won't challenge their belief of a Creator because I can't (I can't challenge atheists either). I won't even challenge their belief of a flat earth, separate origin of humans and broccoli, etc., provided they admit, as some have to me, that there's no evidence and that they just take it on faith. I will challenge them, however, if they imply that 99+% of scientists who work in relevant fields, and who have the most to gain by falsifying evolution, are either wrong or "conspiring to expel."
> >
> I agree.

On Sunday, June 24, 2012 3:48:34 PM UTC-4, Arkalen wrote:

On Sunday, June 24, 2012 3:48:34 PM UTC-4, Arkalen wrote:

On Sunday, June 24, 2012 3:48:34 PM UTC-4, Arkalen wrote:

On Sunday, June 24, 2012 3:48:34 PM UTC-4, Arkalen wrote:

On Sunday, June 24, 2012 3:48:34 PM UTC-4, Arkalen wrote:

(pardon if 2nd or 3rd try - computer hiccups)

Just food for thought for new readers. If I can change one accusation of "you're lying for Jesus" to a polite "So what exactly did Jesus do, when and how" it's worth it.

[Glenn]

On Jun 24, 2:01 pm, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Sun, 24 Jun 2012 13:52:44 -0700 (PDT), Glenn <GlennShel...@msn.com>

Yet many other sources claim that the algae are what provides the
colors:

"The tissues of corals themselves are actually not the beautiful
colors of the coral reef, but are instead clear. The corals receive
their coloration from the zooxanthellae living within their tissues."

http://www.marinebiology.org/coralbleaching.htm

How do we determine the truth here?

[wiki trix]

How about just let it go.

[Richard Norman]

It is a question of science and hence worthy of analysis.

[Richard Norman]

On Sun, 24 Jun 2012 18:13:40 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

Your source is old. The fluorescent protein pigments are quite
uncontested. Here is another source:

Diversity and Evolution of Coral Fluorescent Proteins
Alieva et al.
PLoS ONE 3(7): e2680. doi:10.1371/journal.pone.0002680
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0002680

"Last but not least, coral FPs are major determinants of the coral
reef color diversity [7], [8], [9], [10], accounting for practically
every visible coral color other than the brown of the photosynthetic
pigments of algal symbionts (possible exception is the non-fluorescent
yellow in some representatives of Poritidae and Dendrophylliidae that
may be due to melanin-related pigments; C. Palmer, pers. comm.). A
suggestion that the red appearance of some corals may be predominantly
due to the phycoerythrins of cyanobacterial symbionts rather than
intrinsic GFP-like proteins [11] was not supported in subsequent
experiments ."

And the fluorescent proteins are in fact the source of the colors:

"Reef-building corals are renowned for their brilliant colours yet the
biochemical basis for the pigmentation of corals is unknown. Here, we
show that these colours are due to a family of GFP-like proteins that
fluoresce under ultraviolet (UV) or visible light."
http://www.springerlink.com/content/u0jynnkvqd8r5apv/

These are proteins and the genes coding for the proteins are in the
coral genome. The first member of the family found was the green
fluorescent protein (more commonly known simpy as GFP) from the
jellyfish Aequorea. It is also present in Sea Pansy and other
cnidaria which do not have symbiotic dinoflagellates.

[wiki trix]

Yes. And I am sure it has been analyzed by researchers that had good
work to contribute. However, I still think that it would be best for
Glenn to let it go.

[Richard Norman]

Glenn seems genuinely interested in this and I definitely am. It is
not necessary for you to read these posts.

It turns out that the GFP family of proteins is quite widespread in
the bilateria, found in cnidaria, arthropods, and chordates.

[Glenn]

Just a friendly bit of advice? My advice for you is to explain why,
convincingly.

[Glenn]

On Jun 24, 7:58 pm, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Sun, 24 Jun 2012 18:13:40 -0700 (PDT), Glenn <GlennShel...@msn.com>

> PLoS ONE 3(7): e2680. doi:10.1371/journal.pone.0002680http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0002680

>
> "Last but not least, coral  FPs are major determinants of the coral
> reef color diversity [7], [8], [9], [10], accounting for practically
> every visible coral color other than the brown of the photosynthetic
> pigments of algal symbionts (possible exception is the non-fluorescent
> yellow in some representatives of Poritidae and Dendrophylliidae that
> may be due to melanin-related pigments; C. Palmer, pers. comm.). A
> suggestion that the red appearance of some corals may be predominantly
> due to the phycoerythrins of cyanobacterial symbionts rather than
> intrinsic GFP-like proteins [11] was not supported in subsequent
> experiments ."
>
> And  the fluorescent proteins are in fact the source of the colors:
>
> "Reef-building corals are renowned for their brilliant colours yet the
> biochemical basis for the pigmentation of corals is unknown. Here, we
> show that these colours are due to a family of GFP-like proteins that
> fluoresce under ultraviolet (UV) or visible light."http://www.springerlink.com/content/u0jynnkvqd8r5apv/
>
> These are proteins and the genes coding for the proteins are in the
> coral genome.  The first member of the family found was the green
> fluorescent protein (more commonly known simpy as GFP) from the
> jellyfish Aequorea.  It is also present in Sea Pansy and other
> cnidaria which do not have symbiotic dinoflagellates.

That the genes responsible have been identified is fairly definitive.
I could not remember where I got the impression that the corals were
responsible. Its understandable how many sources could either be
repeating old assumptions or are misunderstood. Most coral polyps are
essentially transparent, and when xooks are displaced from within the
polyps most or all color is lost. I suppose I'd lose some color if
almost all of my energy input was removed.
But I still wonder if you are right that the algae do not provide any
biochemical "route" for coral protein synthesis. The first reference
you provided only served to confuse me about that.

[wiki trix]

You could just google it.

[Glenn]

Google for what?

[Richard Norman]

On Sun, 24 Jun 2012 20:29:27 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

The fluorescent pigments are pure protein -- no cofactors. That would
make it difficult to understand how the algae could be involved in the
actual synthesis. Of course one of the hypothesis for the function of
the colors is protective, to protect the algae from excess light or
particular wavelengths which are damage or inhibit the photosynthetic
machinery. The algae may be producing factors that control gene
expression of the proteins.

However the protein family which includes the fluorescent pigments is
found and expressed in many organisms that do not have symbiotic
algae.

[Devils Advocaat]

On Jun 24, 5:11 am, Arkalen <arka...@inbox.com> wrote:
> So there are these creationists I'm talking to and one brought up how
> Acropora corals are brightly colored, and why would that be, wouldn't
> that make them vulnerable to predators ?
>
> So looking it up it seems the main predators in question are flatworms
> and sea snails, not sure how much Acropora have to hear from those
> hawk-eyed killers... but I'm not seeing many positive reasons they might
> be brightly colored either. Mating ? I don't think they have eyes.
> Poisonous ? If their main predators are flatworms and sea snails... I
> don't even know much what corals do in life. Grow and leech off their
> algae friends like lichens I guess ? The color could also be a random
> algae color but even plants are rarely brightly colored for random
> reasons alone.
>
> Does anyone here know a lot about corals ? Or is much more skilled at
> Google than I am ?

The Wiki article explains why these corals are so colourful.

It's because of a symbiotic algae called zooxanthella that live in the
cells of the coral polyps.

But that's not all those algae do, they produce energy for the polyp
via photosynthesis.

[Richard Norman]

You haven't been reading the posts on this thread.

[Glenn]

On Jun 25, 4:17 am, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Sun, 24 Jun 2012 20:29:27 -0700 (PDT), Glenn <GlennShel...@msn.com>

Do these pigments have a lifetime warranty or do they require periodic
replacement? It seems odd that "as soon as" the algae are ejected the
pigment dissapears.

[Richard Norman]

On Mon, 25 Jun 2012 10:29:36 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

Pretty much all functional (as opposed to structural) proteins have
limited lifetimes and must be synthesized with the old ones degraded.
I am not sure how long it takes for coral to bleach. It is not
instantaneous. Light intensity and color partially regulates
expression of the fluorescent pigments. But I can't find references
to what happens to these pigments in bleached coral.

[Glenn]

On Jun 25, 11:42 am, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Mon, 25 Jun 2012 10:29:36 -0700 (PDT), Glenn <GlennShel...@msn.com>

Isn't "fluorescent pigments" a misnomer with respect to biological
processes?

[Richard Norman]

On Mon, 25 Jun 2012 11:55:01 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

>Isn't "fluorescent pigments" a misnomer with respect to biological
>processes?

I thought about that when typing the words. I used "pigment" to refer
to something that gives color, no matter the mechanism. Some use the
word specifically for color produced by differential absorption of
light of different wavelength so that structural colors don't count.

[Glenn]

On Jun 25, 12:23 pm, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Mon, 25 Jun 2012 11:55:01 -0700 (PDT), Glenn <GlennShel...@msn.com>

> wrote:
>
> >Isn't "fluorescent pigments" a misnomer with respect to biological
> >processes?
>
> I thought about that when typing the words.  I used "pigment" to refer
> to something that gives color, no matter the mechanism.  Some use the
> word specifically for color produced by differential absorption of
> light of different wavelength so that structural colors don't count.

Speaking of structural proteins, aren't some versions of GFP's
structural? GloFish, for instance, indicating some research exists on
the subject. Surely under stress, GloFish do not lose their colors?

[Richard Norman]

On Mon, 25 Jun 2012 12:40:54 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

You are confusing several factors, here.

First, there are lots of non-structural proteins that are constantly
replaced so they don't disappear. The hemoglobin in your red cells is
called a "pigment" and it has a very limited lifetime. Yet your blood
doesn't bleach.

Second, GloFish are genetically modified to produced jellyfish GFP. It
turns out that GFP is a very convenient marker because you can see
exactly what cells make it: just shine UV on them! So it is now a
standard tool of research. Introduce a new or modified gene into an
organism with controls on when and where it is to be expressed. If
you link that gene and its expression with GFP, then you can see
exactly what is happening with the gene you really are interested in.
Then various people started producing genetically modified creatures
of all varieties with GFP just for fun and profit. That is the case
with GloFish.

[Glenn]

On Jun 25, 1:01 pm, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Mon, 25 Jun 2012 12:40:54 -0700 (PDT), Glenn <GlennShel...@msn.com>

So what did I confuse? There was no implication that all proteins are
structural or that GloFish are not a lab creation.
Are you now just going to roll over and turn out the light?

[Richard Norman]

On Mon, 25 Jun 2012 13:08:26 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

You definitely suggested that GloFish have GFP as structural proteins.

I like a smoke, first.

[Glenn]

On Jun 25, 1:15 pm, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Mon, 25 Jun 2012 13:08:26 -0700 (PDT), Glenn <GlennShel...@msn.com>

Not at all, it was a question. You don't bring me flowers anymore.

[Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org]

Antique coral ornaments are coloured, and
presumably are dead? Just wondering about that.

[Glenn]

On Jun 25, 3:56 pm, "Robert Carnegie: Fnord: cc talk-

orig...@moderators.isc.org" <rja.carne...@excite.com> wrote:
> On Monday, June 25, 2012 7:42:25 PM UTC+1, Richard Norman wrote:

> > On Mon, 25 Jun 2012 10:29:36 -0700 (PDT), Glenn <GlennShel...@msn.com>

Yes. Corals collect various minerals and poop them out, creating these
skeletons. I have some red coral for hobby projects that are colored
all the way through. There is a lot of confusion or old material
around.

"The polyps make skeletons (or corallites) of calcium carbonate around
themselves. The beautiful colour of corals comes from the colourful
tentacles of the coral polyps and the zooxanthellae algae that live in
the tissues of many species."
...
"..the zooxanthellae with their brilliant reds, oranges and browns,
give corals their beautiful colour."

http://www.qm.qld.gov.au/microsites/biodiscovery/03sponges-and-corals/structure-classification-function.html

[Eric Root]

On Jun 24, 12:11�am, Arkalen <arka...@inbox.com> wrote:
> So there are these creationists I'm talking to and one brought up how
> Acropora corals are brightly colored, and why would that be, wouldn't
> that make them vulnerable to predators ?
>
> So looking it up it seems the main predators in question are flatworms
> and sea snails, not sure how much Acropora have to hear from those
> hawk-eyed killers... but I'm not seeing many positive reasons they might
> be brightly colored either. Mating ? I don't think they have eyes.
> Poisonous ? If their main predators are flatworms and sea snails... I
> don't even know much what corals do in life. Grow and leech off their
> algae friends like lichens I guess ? The color could also be a random
> algae color but even plants are rarely brightly colored for random
> reasons alone.
>
> Does anyone here know a lot about corals ? Or is much more skilled at
> Google than I am ?

The real clincher is, why would God make the colors bright, since
bright colors make them vulnerable to predators? If you even try to
explain scientifically, you are ceding them the original premise that
it is a problem (or not) for science when it is a problem (or not) for
any explanation.

[wiki trix]

As a freshly minted religious person, let me try to answer that.
Here's the deal... God likes colors sometimes. Q.E.D. Hey... this is
easier than I thought it would be...

[Arkalen]

(2012/06/26 21:13), Eric Root wrote:
> On Jun 24, 12:11 am, Arkalen<arka...@inbox.com> wrote:
>> So there are these creationists I'm talking to and one brought up how
>> Acropora corals are brightly colored, and why would that be, wouldn't
>> that make them vulnerable to predators ?
>>
>> So looking it up it seems the main predators in question are flatworms
>> and sea snails, not sure how much Acropora have to hear from those
>> hawk-eyed killers... but I'm not seeing many positive reasons they might
>> be brightly colored either. Mating ? I don't think they have eyes.
>> Poisonous ? If their main predators are flatworms and sea snails... I
>> don't even know much what corals do in life. Grow and leech off their
>> algae friends like lichens I guess ? The color could also be a random
>> algae color but even plants are rarely brightly colored for random
>> reasons alone.
>>
>> Does anyone here know a lot about corals ? Or is much more skilled at
>> Google than I am ?
>
> The real clincher is, why would God make the colors bright, since
> bright colors make them vulnerable to predators?

That's an excellent question actually; that poster's original example
was dandelions making nectar for bees even though they reproduce
asexually and the reason there was clear : God would do this to feed
bees, natural selection would have no reason to feed bees with no profit
to the dandelion. And they even mentioned corals being hermaphrodites
which made me think that example might be similar but that actually
makes no sense.
Maybe it's just "so that they could prettily decorate our aquariums"...
(remember the banana video ??). I don't think it matters that much
insofar I acknowledge that structures that are not beneficial to the
organism that has them *are* a legitimate problem for evolution. A
problem in the "this is unusual and requires investigation" sense, not
the "EVOLUTION DISPROVED" sense.

> If you even try to
> explain scientifically, you are ceding them the original premise that
> it is a problem (or not) for science when it is a problem (or not) for
> any explanation.
>

I disagree; whether anything is a problem for any explanation depends on
what the explanation predicts. Gradual evolution by natural selection is
a specific process that can't accommodate everything, and one thing we
don't expect to see is complex structures that have no use whatsoever.
There are processes by which those can appear (like if they're vestigial
for example), but those are specific too.

Goddidit doesn't make any actual predictions, but it usually has the
implication God is aiming for functionality. So non-functional
structures would be a problem for that explanation just as much as for
evolution, but structures that are useless to the species that has them
*but are beneficial to another species* can easily be explained by
special creation ("God made the trees bear fruit for us to eat!") (I
mean, if you're willing not to think it through much), whereas in an
evolutionary context they are something that requires an explanation.

[jillery]

IIUC corals appear brightly colored only when artificial lights are
shined on them. In the normal light-attenuating environment in which
they and their predators live, corals appear rather drab. So, there's
no predator vulnerability problem for God to worry about.

As for the colors themselves, I assume corals need lots of pigment in
order to absorb as much light as possible. If so, I would expect the
more intense and darker colors to follow depth. I don't know if that
is actually correct.

[wiki trix]

Try SCUBA. Lots of nice colors in natural light.

[jillery]

To what depth?

[wiki trix]

My deepest dive was 100 feet. But my best dives (for stuff like coral
and pretty critters) is about 10 to 20 feet.

[jillery]

And by "nice colors" I assume you mean that as equivalent to the topic
title, are you asserting you saw bright colorful corals at those
depths with just the ambient light from the sun?

[Glenn]

On Jun 26, 12:08 pm, jillery <69jpi...@gmail.com> wrote:
> On Tue, 26 Jun 2012 11:27:59 -0700 (PDT), wiki trix
>
>
>
>
>
>
>
>
>

Trixie's scuba mask is a View-Master.

[wiki trix]

On Jun 26, 3:08 pm, jillery <69jpi...@gmail.com> wrote:
> On Tue, 26 Jun 2012 11:27:59 -0700 (PDT), wiki trix
>
>
>
>
>

yuppers

[Walter Bushell]

In article
<6c6936e7-616c-48f4...@h10g2000pbi.googlegroups.com>,

True, my most memorable dive was a (shallow) shore dive, for getting
up close in personal with critters. But you don't get to breath air
under great pressure in a shore dive, usually.

--
This space unintentionally left blank.

[Walter Bushell]

In article
<077dac40-2fb1-4b22...@mi5g2000pbc.googlegroups.com>,

One can also see colorful fish, crabs and other denizen of the
shallows. Turtles!

[William Morse]

On 06/24/2012 12:38 PM, Arkalen wrote:
> (2012/06/24 22:53), Richard Norman wrote:

>> On Sun, 24 Jun 2012 13:11:02 +0900, Arkalen<ark...@inbox.com> wrote:
>>
>>> So there are these creationists I'm talking to and one brought up how
>>> Acropora corals are brightly colored, and why would that be, wouldn't
>>> that make them vulnerable to predators ?
>>>
>>> So looking it up it seems the main predators in question are flatworms
>>> and sea snails, not sure how much Acropora have to hear from those
>>> hawk-eyed killers... but I'm not seeing many positive reasons they might
>>> be brightly colored either. Mating ? I don't think they have eyes.
>>> Poisonous ? If their main predators are flatworms and sea snails... I
>>> don't even know much what corals do in life. Grow and leech off their
>>> algae friends like lichens I guess ? The color could also be a random
>>> algae color but even plants are rarely brightly colored for random
>>> reasons alone.
>>>
>>> Does anyone here know a lot about corals ? Or is much more skilled at
>>> Google than I am ?
>>

>> The source you want is "The role of host-based color and fluorescent
>> pigments in photoprotection and in reducing bleaching stress in
>> corals" by Salih, Cox, et al.
>> http://www.coralcoe.org.au/research/publications/Salih_ICRS_2006.pdf
>>
>> which says
>>
>> Coral tissue colors result from both the intracellular symbiotic
>> dinoflagellates and the host’s own cellular pigments. The brownish
>> colors are due to the symbionts’ photosynthetic pigments; the bright
>> purple-blue and fluorescent colors are produced by the coral host and
>> are proteins closely related to Green Fluorescent Protein (GFP). One
>> of the documented biological functions of GFP-like pigments in corals
>> is light optimization. When light is excessive, GFPs reduce symbionts’
>> photoinhibition and photo-damage to coral’s tissues. Here we explored
>> further the ecological roles of coral coloration...These results
>> further substantiate earlier findings that GFP-like pigments reduce
>> photoinhibition and the severity of bleaching-related physiological
>> damage of corals.
>>
>>
>> There is also "Pigmentation as a strategy for reducing solar damage in
>> reef-building corals" by Kluter (2003)
>> http://espace.library.uq.edu.au/view/UQ:251950
>>
>> whcih says
>>
>> Reef-building corals are renown for their striking pigmentation. Many
>> coral pigments have been identified as homologs of the Green
>> Fluorescent Protein (GFP) of the Hydrozoan jellyfish Aequorea
>> victoria, yet little is known about their possible biological
>> function. Coral pigments are thought to have a role in the
>> photobiology of symbiotic corals, by both reducing and enhancing the
>> amount of light captured by symbiotic dinoflagellates. This thesis
>> explored the ecological significance of GFP-homologs in reef-building
>> corals, particularly those that are green fluorescent. It presents the
>> first comprehensive data set on spatial distribution patterns of these
>> pigments in reef-building corals. Moreover, it investigates how their
>> abundance is linked to their environment and the presence of other
>> pigments such as mycosporine-like amino acids (MAAs) and peridinin
>> that are known to regulate light stress in coral-algae associations.
>>
>> Understanding the function of compounds associated with the
>> photobiology of coral symbiosis is integral to evaluate the full
>> impact of their ability to protect shallow water corals and hence how
>> these corals survive successfully in an extreme environment. The light
>> absorbing properties of corals and their interaction with solar
>> radiation is of a complex nature, which makes it often difficult to
>> gain a complete understanding of how these elements have interacted in
>> an ecological and evolutionary setting. This thesis however, indicates
>> that host pigments may play a major role of in regulating the solar
>> flux that reaches the dinoflagellate partner of the coral-algal
>> association. By regulating this flux in both, ultraviolet and
>> photosynthetically active spectra, host pigments show the potential to
>> be a critical element in determining how and where corals are found
>> within the extreme light gradients that are characteristic for the
>> shallow tropical sea that they inhabit.
>>
>
> Thank you very much Richard, that is fascinating and completely awesome!
> Talk.origins comes through yet again ^^
> Thank you also to the all the others who responded.
>

I want to add my thanks to Richard for shedding much light on the
subject. I was following some of this thread and scratching my head as
to why corals should be brightly colored - I was even about to suggest
neutral drift (perish the thought!). But mediation of photochemical
damage sounds like a reasonable explanation. And it is likely more
complex than that, given Orgel's rule.

[jillery]

And these bright colors in the corals, are they all blues and greens?

[jillery]

On Tue, 26 Jun 2012 21:01:22 -0400, Walter Bushell <pr...@panix.com>
wrote:

Are fish and turtles corals?

[wiki trix]

On Jun 27, 1:43 am, jillery <69jpi...@gmail.com> wrote:
> On Tue, 26 Jun 2012 12:10:12 -0700 (PDT), wiki trix
>
>
>
>
>

No. They are various colors. Look. You talk like a psychoanalyst. I am
getting tired of this dialectic. What are bleep you driving at?

[Glenn]

Do the meds make you lightheaded so you have to load up on the lead on
these dives?

[wiki trix]

Actually I am more buoyant than average. And ues, I do require more
weight than average when I dive. Must be part tortoise.

BTW, for others here... how much variation in density is there among
people? I think that in my case I may have larger than average lung
capacity. When I was a kid, I recall that I could hold my breath
longer than my friends. Rather anecdotal I guess. Wonder how much
variation there is.

[Arkalen]

Given the variation in bone density and fat and muscle content I'd say
it probably varies quite a lot (depending on how we define "a lot" though).

[Richard Norman]

Larger lung capacity definitely makes you more bouyant. But probably
the greatest variation is percentage of body mass that is fat.

[Richard Norman]

On Wed, 27 Jun 2012 01:43:12 -0400, jillery <69jp...@gmail.com>

The fluorescent proteins in coral, although in the "green" family,
come in all colors including infrared.

[wiki trix]

On Jun 27, 9:13 am, Richard Norman <r_s_nor...@comcast.net> wrote:
> On Wed, 27 Jun 2012 05:36:52 -0700 (PDT), wiki trix
>
>
>
>
>

Who you callin' fat buster?

[jillery]

I regret you feel that way. Perhaps what you're reacting to is my
habits in dealing with hypercritical pedantry. Since I stated my
point explicitly and clearly, and since it is you who challenged me, I
can only wonder what the bleep you're driving at.

It appears we have different conclusions wrt the brilliance of
underwater coral colors. No doubt some of it is based on my lesser
experience, and some of it is based on our different understandings of
'brilliance'. In either case, this topic apparently has moved on to
subjects more interesting to other T.O. denizens, and I defer to them.

[Josh Hayes]

jillery <69jp...@gmail.com> wrote in
news:rimou7tsmodap7ons...@4ax.com:

[snippity snip snap snoop]

> It appears we have different conclusions wrt the brilliance of
> underwater coral colors. No doubt some of it is based on my lesser
> experience, and some of it is based on our different understandings of
> 'brilliance'. In either case, this topic apparently has moved on to
> subjects more interesting to other T.O. denizens, and I defer to them.

I am astonished that nobody pointed this out already, but of course
corals themselves are virtually colorless -- the color of the coral
tissues (at least in hermatypic forms) is provided by the endosymbiotic
algae (or "zooxanthellae") inhabiting the polyps.

You may have read reports of temperature-stressed corals "bleaching", or
losing their endosymbionts; this leaves the coral tissues white. (Such
colonies may recover, or they may die.)

Because the colony itself is a thin skin of tissue stretched over a
calcareous substrate, it's not exactly appetizing: the effort of
consumption produces a woefully small reward. Corals have always been
assumed to be competition-limited, rather than predator-limited. My
dissertation work, he said modestly, showed that in Caribbean reef
communities, corallivory was in fact a minor factor except when coupled
with abiotic disturbances (e.g. hurricanes). Of course, in Indo-Pacific
reef communities there are corallivores with potentially devastating
influence, most particularly the "crown of thorns" echinoderm,
_Acanthaster planci_, the populations of which exhibit irruptive
cycling.

People forget that I was a scientist in a previous lifetime, some
twenty-five years ago. Lord knows, _I_ try to forget.

-JAH

[Arkalen]

On 28/06/12 17:34, Josh Hayes wrote:
> jillery <69jp...@gmail.com> wrote in
> news:rimou7tsmodap7ons...@4ax.com:
>
> [snippity snip snap snoop]
>
>> It appears we have different conclusions wrt the brilliance of
>> underwater coral colors. No doubt some of it is based on my lesser
>> experience, and some of it is based on our different understandings of
>> 'brilliance'. In either case, this topic apparently has moved on to
>> subjects more interesting to other T.O. denizens, and I defer to them.
>
> I am astonished that nobody pointed this out already, but of course
> corals themselves are virtually colorless -- the color of the coral
> tissues (at least in hermatypic forms) is provided by the endosymbiotic
> algae (or "zooxanthellae") inhabiting the polyps.

You know, other than most of the participants in this thread who pointed
this out ? Which caused Glenn and Richard Norman to have an extended
conversation as to how one could square this with Richard's well-sourced
post that said the colours belonged to the corals themselves ?

>
> You may have read reports of temperature-stressed corals "bleaching", or
> losing their endosymbionts; this leaves the coral tissues white. (Such
> colonies may recover, or they may die.)
>
> Because the colony itself is a thin skin of tissue stretched over a
> calcareous substrate, it's not exactly appetizing: the effort of
> consumption produces a woefully small reward. Corals have always been
> assumed to be competition-limited, rather than predator-limited. My
> dissertation work, he said modestly, showed that in Caribbean reef
> communities, corallivory was in fact a minor factor except when coupled
> with abiotic disturbances (e.g. hurricanes). Of course, in Indo-Pacific
> reef communities there are corallivores with potentially devastating
> influence, most particularly the "crown of thorns" echinoderm,
> _Acanthaster planci_, the populations of which exhibit irruptive
> cycling.
>
> People forget that I was a scientist in a previous lifetime, some
> twenty-five years ago. Lord knows, _I_ try to forget.
>
> -JAH
>

Now, what this thread *hasn't* had a lot of is discussions of
corallivory, so thank you for teaching me a new word :)

[Richard Norman]

On Thu, 28 Jun 2012 11:34:23 -0500, Josh Hayes <jos...@SPAMblarg.net>
wrote:

I am astonished that you have not bothered to read some of the posts
in this thread that described the very vivid colors produced in some
coral by fluorescent proteins produced by the coral, themselves, not
by the symbiotic photosynthesizers. This is all pretty new, within
the last ten years or so. What you say was the accepted dogma before
then. What you say is true of many corals but not the brightly
colored ones.

[jillery]

Josh Hayes presented two separate points. His larger point directly
relates to an argument previously made, that bright coral colors
should be selected against due to predation. If in fact coral
populations are not substantially limited by predation, and/or their
predators are not color sensitive, their bright colors would not be
selected against for that reason. Of course, there might be other
reasons why bright coral colors are selected against, but predation is
not one of them.

[Josh Hayes]

Richard Norman <r_s_n...@comcast.net> wrote in
news:qc2pu7567g70nmd5r...@4ax.com:

> I am astonished that you have not bothered to read some of the posts
> in this thread that described the very vivid colors produced in some
> coral by fluorescent proteins produced by the coral, themselves, not
> by the symbiotic photosynthesizers. This is all pretty new, within
> the last ten years or so. What you say was the accepted dogma before
> then. What you say is true of many corals but not the brightly
> colored ones.

Good lord, you expect me to read talk.origins? It's bad enough I have to
read s.b.e.

And as I said, I've been out of the science biz (or at least, the coral
biz) since about, umm.... 1989. So yeah, I'm out of touch. I stand by the
community-ecology-related points (another finding in my dissertation was
that the critters I was looking at [Coralliophila abbreviata] used
chemotaxis to find preferred prey), and I'd be very surprised to find coral
colors having any influence on their risk of predation (especially since
the observed fluorescence is under short wavelengths and the penetrance of
those wavelengths is very poor).

But hey, I'll read up on it.

-jah

[Richard Norman]

On Thu, 28 Jun 2012 19:32:52 -0500, Josh Hayes <jos...@SPAMblarg.net>
wrote:

You are quite right about having to plow through stuff here. So just
go directly to

http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0002680
which gives you full text.

I think one of the earliest announcements of this was
http://www.springerlink.com/content/u0jynnkvqd8r5apv/

And there is
http://www.coralcoe.org.au/research/publications/Salih_ICRS_2006.pdf
and
http://espace.library.uq.edu.au/view/UQ:251950

[Arkalen]

He's not talking about the influence of colors on their risk of
predation, but the reason corals have those colors in the first place.

[jillery]

As you have pointed out to me before, there can be more than one point
in a topic. Josh Hayes acknowledged your point. Perhaps you could
reciprocate and acknowledge his.

[Arkalen]

I'm sorry, I honestly did not see where Josh Hayes acknowledged my point
(he hasn't responded to me that I noticed actually, which isn't an issue
at all except that that means I'm not sure exactly which point of mine
he acknowledged because I have a few posts in this thread saying
different things), and it seemed to me I did acknowledge his point in
that I thanked him for giving some details into the predation pressures
on corals. I realize in the two posts in which I replied to him I
probably appear to be more chiding than I mean, because the paltry point
with which I disagree is easier to respond to than the substantial point
which I appreciate but can't say much about because of my lack of
knowledge... but other than voicing my appreciation (which I had thought
I did) I don't know how to correct that.

[Josh Hayes]

Arkalen <ark...@inbox.com> wrote in
news:MSB*2g...@news.chiark.greenend.org.uk:

> He's not talking about the influence of colors on their risk of
> predation, but the reason corals have those colors in the first place.

There are two questions that might be - first, "why do corals have those
colors in the first place", and second, "why are those fluorescence
pathways maintained in the population". The first strikes me as a question
more about ontology than biology. The second is one that's potentially
biologically interesting (surely there's some metabolic cost to this
phenomenon, and therefore one can surmise that there may be some sort of
adaptive reason for it), but I am loathe to embark on adaptive story-
telling in the absence of useful data.

-jah

[Richard Norman]

On Fri, 29 Jun 2012 18:00:50 -0500, Josh Hayes <jos...@SPAMblarg.net>
wrote:

I gave you citations for four research articles. Two of them are
specifically about possible roles of the colors. The other two are
not specifically about the function but include discussion of possible
functions.

You are wise (and almost unique here) in not engaging in idle
speculation in the absence of useful data. However it is not
difficult to find useful data. You could simply google "function of
coral fluorescent protein".

[jillery]

A point you made to Josh Hayes was that he didn't address "Richard's
well-sourced post". Given that, ISTM any post where Josh Hayes
acknowledges said post also acknowledges your point, whether or not
his post is addressed to you. YMMV.

You thanked Josh Hayes for teaching you a new word. ISTM his post
contained a larger and more useful point than that. YMMV. It's also
possible I missed where you voiced your appreciation. Perhaps you did
so offline.

Of course, you are you, and I am me, and we are both expressing our
own opinions, not that either of us care about that, right? I for one
have no wish to make this a drawn-out exchange.

Thank you for your reply.