[Coral-List] Darwin was WRONG about reef formation

Tue Oct 20 14:56:29 UTC 2020

*Darwin and Atoll Formation*

Many years ago I was in a debate about the origin of Florida's coral reefs
with some colleagues -
I used many papers by T. Wayland Vaughan in my argument.  Using the Darwin
mosel of reef formation - the response I got back was as follows:

"*Although Vaughan was bright and savvy, he was not always right. For
example, because of the shape, Vaughan (1914), called the Dry Tortugas an
atoll. By convention and consensus, an atoll is a reef superimposed on a
subsiding volcano. Dry Tortugas does not meet these criteria."*

My response to this comment goes back to the historical discussions of this
argument and follows below:

Much of the original work that systematically described the geology and the
organisms found in and around the coral reefs of the Florida Keys was
reported in a series of publications by T. Wayland Vaughan (1909, 1910,
1911, 1912, 1914a, 1914b, 1914c, 1914d, 1915a, 1915b, 1916, 1918, 1919).
Much of this seminal work stands to this day for its insightfulness and
incredible accuracy.

The indictment of citing Vaughan’s work as being 'incorrect' deserves
attention.  For instance, Vaughan (1914) correctly interpreted the Tortugas
to be an atoll of constructional phenomena owing their configuration to the
prevailing winds and currents (also discussed in Shinn et al. 1989).

Based on his subsidence theory of atoll development, Darwin (1842) believed
that there were no true atolls in the Atlantic. Interestingly, Darwin never
visited the Caribbean and in the First Edition of his book, *On the
Structure and Distribution of Coral Reefs*, he downplayed the importance of
coral reefs in the New World altogether.

Today, however, most reef scientists define an *atoll* following the
terminology in McNeil (1954) as "...an annular reef enclosing a lagoon in
which there are no promontories other than reefs and [islets] composed of
reef detritus" and Fairbridge (1950) "...in an exclusively morphological
sense, [as] ...a ring-shaped ribbon reef enclosing a lagoon in the center."

Atoll comes from a very specific administrative Maldivian term that has
been inadequately used to only designate annular-shaped reef structures in
the Pacific.  By defining an atoll by its intended geomorphic form rather
than by origin (a ringlike coral island and reef that nearly or entirely
encloses a lagoon. [Maldivian *atolu*; probably akin to Sinhalese *ätul*,
interior [from the interior lagoon]), atolls have been described for all
tropical oceans basins and there have been at least 15 atolls recognized in
the coral reef literature for the Caribbean (see papers by Milliman,
Stoddart; Gischler, Carricart-Ganivet and Beltrán-Torres 1998; van der
land; Diaz et al.; ) including those of the Dry Tortugas (Vaughan 1914;
Shinn et al. 1977; 1989).  None of these Caribbean atolls conform to the
classic Darwinian mode of formation that was based entirely on observations
from the Pacific (French Polynesia).  In fact, much of the discussion of
coral reef theory has been waged over the interpretation of these relations
(see Dobbs 2005) and many of these continue (see Smith 1971, for a dated
but excellent review). It is precisely the fact that Caribbean atolls were
fundamentally different from their Pacific counterparts that led Vaughan to
seek an alternative explanation. As Ladd (1950) pointed out “the more that
is discovered about the geological history of any reef or reef-encircled
island, the more complicated its history appears.” There is certainly no
convention or consensus that *all* atolls are “*reef*[s]* superimposed on a
subsiding volcano.”  *

*So let's all give Darwin a break - and also his due.*

As Bill Allison noted - the press release is the thing that spurred this
debate.  Darwin wasn't wrong - especially from the examples he saw in
French Polynesia.  It's just more complicated than most introductory texts
on reef formation lead us to believe.

For those interested in reading a great book about the orgins of the Atoll
debate get your hands on "Reef Madness: Charles Darwin, Alexander Agassiz,
and the Meaning of Coral." By David Dobbs. Pantheon, 320pp. Publication
Date: January 4, 2005

http://daviddobbs.net/smoothpebbles/darwins-first-theory-of-evolution/

enjoy

Bill

On Tue, Oct 20, 2020 at 8:13 AM Bill Allison via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> I have read the paper. It does not claim that Darwin's coral reef theory
> was "fatally flawed" although it does little to discourage that
> interpretation.  It seems to be focused on coral reefs and atolls sprouting
> atop carbonate banks and does not seem to address evidence such as almost
> atolls on subsiding volcanoes (e.g., Bora Bora) and does not consider the
> origins of the carbonate banks atop volcanic basements. It seems like the
> press release writers have as is commonly the case, indulged in inaccurate
> hyperbole to attract eyeballs.
> Cheers,
> Bill
>
> On Sat, Oct 17, 2020 at 8:28 AM Douglas Fenner via Coral-List <
> coral-list at coral.aoml.noaa.gov> wrote:
>
> > or so says a new article:
> >
> > Popular piece:
> >
> > Study: Darwin's theory about coral reef atolls is fatally flawed
> >
> >
> >
> http://news.rice.edu/2020/10/12/study-darwins-theory-about-coral-reef-atolls-is-fatally-flawed-2/
> >
> > Original review:
> >
> > The origin of Modern Atolls: Challenging Darwin's Deeply Ingrained Theory
> >
> > https://www.annualreviews.org/doi/10.1146/annurev-marine-122414-034137
> >
> > My thoughts, based on reading the popular article and the abstract for
> the
> > review:
> >
> > Yes, if you define an "atoll" as a ring of coral at the surface, and you
> > carefully ignore that it is on top of an accumulation of up to a mile of
> > coral reef carbonate, which is in turn on top of a two mile tall volcano
> > which all the evidence shows has indeed subsided with the ocean floor
> plate
> > as it moves across the ocean, then yes, sea level fluctuations with the
> > glaciation cycle are widely acknowledged to affect the coral reef
> > structure.  It appears that maybe the new thing in this review is that
> the
> > present ring is relatively young and built on top of the raised ring left
> > from low sea level stands when rainwater was dissolving the carbonate in
> > the center of the ring.  Actually, I don't think even that is new, though
> > their being a flat topped bank in between time may be new.  This is a
> > further embellishment on top of the Darwin theory, NOT a disproof of his
> > theory, which is heavily documented.  The argument back then was whether
> > there was a volcano under the carbonate, which drilling proved was
> correct
> > and is no longer in doubt.
> >      Perhaps by reading the entire review it will be clear that the
> review
> > isn't saying that Darwin was wrong about subsidence and a volcano being
> > under the carbonate, or that there was a sequence from fringing to
> barrier,
> > to atoll, but even the title of the review implies it is.  But of course
> > you attract a lot more attention saying that "Darwin was wrong."
> >       What do geologists think?
> > Cheers, Doug
> >
> >
> > --
> > Douglas Fenner
> > Lynker Technologies, LLC, Contractor
> > NOAA Fisheries Service
> > Pacific Islands Regional Office
> > Honolulu
> > and:
> > Coral Reef Consulting
> > PO Box 7390
> > Pago Pago, American Samoa 96799  USA
> >
> > “Don't think of it as the warmest month of August in California in the
> last
> > century. Think of it as one of the coolest months of August in California
> > in the next century.”
> > <
> >
> https://nature.us17.list-manage.com/track/click?u=2c6057c528fdc6f73fa196d9d&id=38d5d14948&e=190a62d266
> > >
> >
> > The toxic effects of air pollution are so bad that moving from fossil
> fuels
> > to clean energy would pay for itself in health-care savings and
> > productivity gains
> > <
> >
> https://nature.us17.list-manage.com/track/click?u=2c6057c528fdc6f73fa196d9d&id=c9f70ba54f&e=190a62d266
> > >
> > —
> > even if climate change didn’t exist.  In the US alone, decarbonization
> > would save 1.4 MILLION lives in the US alone.  And save $700 Billion a
> > year.
> >
> >
> https://www.vox.com/energy-and-environment/2020/8/12/21361498/climate-change-air-pollution-us-india-china-deaths
> >
> > "Already, more people die  <http://www.nws.noaa.gov/om/hazstats.shtml
> >from
> > heat-related causes in the U.S. than from all other extreme weather
> > events."
> >
> >
> >
> >
> https://www.npr.org/2018/07/09/624643780/phoenix-tries-to-reverse-its-silent-storm-of-heat-deaths
> > _______________________________________________
> > Coral-List mailing list
> > Coral-List at coral.aoml.noaa.gov
> > https://coral.aoml.noaa.gov/mailman/listinfo/coral-list
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> https://coral.aoml.noaa.gov/mailman/listinfo/coral-list

-- 
William F. Precht

 “You never know how strong you are until being strong is the only choice
you have”

Bob Marley

"Courage is not having the strength to go on; it is going on when you don't
have the strength."

Theodore Roosevelt