[Coral-List] Origin of Corals?

[Douglas Fenner]

There are about a dozen theories for the marine biogeographic pattern with
the center of diversity in the Coral Triangle.  I'm not up on the current
state of this, so I'll let others speak to it and will be interested in
what they say.  However, it just so happens that Science just published an
article that appears to me to be relevant, even though it is about birds
and not corals.

Diversity hotspots: coldspots of speciation?
https://science.sciencemag.org/content/370/6522/1268
<https://science.sciencemag.org/content/370/6522/1268?utm_campaign=toc_sci-mag_2020-12-10&et_rid=17045989&et_cid=3593354>

The evolution of a tropical biodiversity hotspot
https://science.sciencemag.org/content/370/6522/1343

I believe that this is the opposite pattern to have been reported in the
first publication to report the diversity pattern for corals (at the genus
level), Stehli and Wells, 1971.  They reported that coral genera in
high-diversity areas were younger than in lower diversity areas.

Theories of why corals show this pattern have been very difficult to test.
Veron 2000 shows the current map for coral species, genera, and families,
might also be on his website, www.coralsoftheworld.org  Fish show the same
pattern as shown in Figure 14-11 on page 308 in Goldberg's text on coral
reefs, based on data from Gerry Allen.  Chuck Birkeland pointed out that
echinoderms show a similar pattern, in his 1989 book chapter on "The
influence of echinoderms on coral-reef communities."  He shows in his Table
1 the data for each class of echinoderms separately, at 10 locations, a
very strong pattern for every class.  Take a look at this chapter, it is an
education on echinoderms on reefs.

One interesting idea was that of the "vortex model", that westward flowing
currents in the Pacific carried newly evolved coral species westward,
causing them to accumulate in the western Pacific area of highest
diversity.  Jokeil & Martinelli, 1992.  There was also a similar study that
modeled the effect of the large number of islands and reefs concentrated in
the western Pacific vs the very sparse reefs in the eastern Pacific, and
reported that was sufficient to produce the pattern on its own as well.  I
never found that publication, does anybody know it?

Cheers,  Doug

Birkeland  1989.   The influence of echinoderms on coral-reef communities.
https://www.researchgate.net/profile/Charles_Birkeland/publication/284657222_The_influence_of_echinoderms_on_coral-reef_communities/links/56b4c6d308aebbde1a7793c7.pdf

Goldberg.  2013.  The biology of reefs and reef organisms.  Univ
Chicago Press

Jokiel & Martinelli.  1992.  The vortex model of coral reef biogeography.
Journal of Biogeography.
https://www.jstor.org/stable/pdf/2845572.pdf

Stehli and Wells.   1971. Diversity and age patterns in hermatypic corals.
http://citeseerx.ist.psu.edu/viewdoc/download

On Sat, Dec 12, 2020 at 6:44 AM Melbourne Briscoe via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> What is the currently accepted theory for the global distribution of
> corals?
> Is it still the "spreading from the epicenter in the Coral Triangle" as I
> learned many years ago or is there a more accepted idea today?
> thanks -
> - Mel Briscoe
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