[Taxacom] panbiogeography critique

michael.heads at yahoo.com michael.heads at yahoo.com
Sun Jun 28 22:38:58 CDT 2009


Dear Robin,
 
That's a CLASSIC example! And I think your resolution of the 'conflicting' geology and biology, using dynamic refugia, makes perfect sense. 
   A century ago geologists concluded that the South Island of New Zealand was completely covered by a Pleistocene ice sheet. The biogeographers replied that this was very unlikely because of all the distinctive endemics. The complete ice sheet theory didn't survive, but now we are repeating the same debate. Over the last five years some  geologists have argued that New Zealand was completely submerged by marine flooding... Again, biogeographers replied that this didn't make sense (and the total submersion people are now backtracking, cf. Trewick, intro to the Darwin issue of Phil Trans Roy Soc. 2008).  
 
   Some geologists also argue that New Caledonia was completely submerged by the sea in the Oligocene but this small island has truly staggering endemism, e.g. five (!) endemic plant families including the basal angiosperm Amborella (see my paper in J. Biogeogr. 2008). Jamaica is also supposed to have been completely submerged in the Tertiary despite plenty of endemism, strange disjunctions in taxa with poor means of dispersal etc. 
 
In all these cases there obviously was a marine transgression - but was it complete? To prove that you would have to have a continuous sequence of limestone all over the island for at least one point in time, which of course is not the case. In these areas, unlike the centre of a continent, the tectonics are very dynamic on a local scale, with uplifts and subsidences affecting areas just tens of metres across. Very small islets will not preserve cursorial mammals etc. but especially in the tropics they can maintain surprisingly diverse biotas of plants, invertebrates, birds, reptiles, etc. The islets may have occurred within the limits of modern New Caledonia, Jamaica etc. or they may have been nearby. In many cases they may have been destroyed completely (by subsidence, erosion, extension etc.).
 
 The main thing is to take the biology seriously. If you simply accept what the geologists say as The Truth (along with 'chance dispersal'), you just short-circuit the whole enterprise of biogeography. In any case, ideas on geology change, sometimes in surprising ways...               

 Can you give me the reference to your work on Ellesmere I.? This is the sort of example that should be pointed out to the many molecular workers who calibrate incredibly sophisticated phylogenies with incredibly naive geology/ecology.   

 
Michael Heads

Wellington, New Zealand.

My papers on biogeography are at: http://tiny.cc/RiUE0

--- On Mon, 6/29/09, Robin Leech <releech at telus.net> wrote:


From: Robin Leech <releech at telus.net>
Subject: Re: [Taxacom] panbiogeography critique
To: michael.heads at yahoo.com
Cc: taxacom-request at mailman.nhm.ku.edu, "John Grehan" <jgrehan at SCIENCEBUFF.ORG>
Date: Monday, June 29, 2009, 2:03 PM


Hi Michael,

In 1963 and 1964, I was up on the northern end of Ellesmere Island at Lake Hazen. I was studying the spiders there (13 spp.).  The surficial (Wisconsinan) geological reports for the area from the Geological Survey of Canada, written by Robert Christie, reported that every single bit of the northern part of Ellesmere Island, and also Pearyland on northern Greenland, had been glaciated during the Wisconsinan glaciation.
Now, Eric Hultein published on the botany of the Canadian Arctic, and recorded several places as refugia during the Wisconsinan, and that one of them was in the northern Ellesmere Island-Pearyland in Greenland area.
Interestingly, I found that some of the spiders there, including the largest species of wolf spider that far north, were strictly a high-Arctic species.

How do we marry these two conflicting pieces of science and fact?

I did it by the concept of a "wandering refugium".
That is, at no time was ALL of the northern part of Ellesmere Island covered all the time,
but over time, all the land had been covered - but not all at the same time.

I proposed that as ice rarely moves very quickly, and
1) that as often there are bare patches within a glacier and between glaciers, and
2) that sometimes there are huge rugs of soil, plants, bushes and trees atop glaciers,
that the refugia (sometimes only a few hundred metres across, but often several kilometres across) moved here and there as different glaciers moved forward then retreated, but always leaving some bare ground.

I think it was carabidologist Carl Lindroth who studies carabid beetles right up against glaciers - this is where there is moisture, so plants, food, and insect life exist in abundance.  Thus the flora and fauna were able to accommodate the glaciers shifting and advancing and retreating, even those biota living right at
the glaciers' edges.

I wonder if some of the species of lizards that appear to be older species than the islands they live on can be explained by something similar?  For example,
what about another island that HAD been near by, but which subsequently sank (gradually), leaving the lizards time to swim or float to nearby newer islands?
Maybe we should be looking for evidence of older sunken islands near these newer islands?  After all, these areas were very volcanically active for a long time.

Robin Leech

----- Original Message ----- From: <michael.heads at yahoo.com>
To: "John Grehan" <jgrehan at sciencebuff.org>
Cc: <taxacom at mailman.nhm.ku.edu>
Sent: Sunday, June 28, 2009 6:50 PM
Subject: Re: [Taxacom] panbiogeography critique







Dear Michael and colleagues,

You ask whether I was kidding when I suggested you might read Pierre Jolivet's 2008 paper in the French journal Le Coleopteriste. The answer is no, I wasn't. Pierre has been publishing on beetles and plant/insect relations etc. since 1947. He has travelled very widely and remains very active (he had a paper in Mol. Phylogen. Evol. 34(3) 2005). I think it's a mistake to ignore these senior workers.
The orthodox teaching in the US still holds that panbiogeography is 'ridiculous', but south of the Rio Grande things are very different. There are now hundreds of publications dealing with panbiogeography (see the Brazilian website http://panbiog.infobio.net/bib/panbiog.htm for a bibliography).
In a separate letter you suggested that the rastafarians were afrocentric. I don't know about your friends in the Lesser Antilles but Ras Tafari himself, in a famous speech to the UN, argued 'That until the color of a man's skin is of no more significance than the color of his eyes... the dream of lasting peace and world citizenship and the rule of international morality will remain but a fleeting illusion, to be pursued but never attained'. This is not afrocentric.
You cite Cracraft's review of our book. Cracraft has indeed written critically on panbiogeogaphy, but note that he became a supporter of vicariance and in a recent paper on parrots (in Proc. Roy. Soc. London 274: 2399-2408. 2007) he is even arguing that high altitude Andean populations have been lifted up in situ, with the orogeny itself (he calls it "passive uplift"). Although this is a fundamental concept in panbiogeography he doesn't cite Croizat. (cf. Gould, who read Croizat's books,corresponded with Croizat (I have the letters), and then 'borrowed' the ideas of punctuated evolution, 'spandrel' (non-adaptive) evolution etc. without acknowledgment). The main thing of course is that the ideas are out there, not where they came from (they weren't original with Croizat anyway).
Apart from these issues, your comments on Antillean biogeography are very interesting indeed. I've never been in the Lesser Antilles but I know Jamaica quite well and in many ways the Caribbean is the geological and biological mirror image of the SW Pacific (see my paper in Biol. J. Linn Soc. 96: 222-245. 2009 on globally 'basal' groups in both areas). One of the main conclusions of panbiogeography, now being confirmed in several molecular clock studies (e.g. on Lord Howe, the Loyalties, French Polynesia etc.), is that endemics on very young islands can be very old. The age of the island seems to be irrelevant and the age of the structure producing the island (subduction zone, propagating fissure or whatever) is more important. The taxa may survive around the subduction zone or fissure as metapopulations on the individually ephemeral islands. Even orthodox molecular clock studies (Thorpe 2005) concluded that Barbados endemic lizards are
older than the island. (It gets tricky because so many clock studies are calibrated using the assumption that island endemics can be no older than their island). More and more West Indian groups are being found to be sister to pan-American mainland groups, not nested in them as predicted in dispersal theory. Lesser Antillean groups can have diverse cosmopolitan sister groups (e.g. 'Cichlherminia' in thrushes). Geologists are at complete loggerheads over Caribbean history - one recent model has Cuba forming west of the Galapagos, another has it off the Guianas...
This is where biology comes in as we have so much more information (large numbers!) than the geologists. Your observations on disjunctions between the Lesser Antilles and the Greater Antilles are absolutely crucial and I'd love to see a detailed discussion of your patterns. These disjunctions (e.g. missing Puerto Rico and the northern Lesser Antilles) are common and were discussed at length by Croizat (do you know any other discussions oif this pattern??) but are now popping up in molecular studies. Just one example: the bird Myadestes genibarbis comprises endemic subspecies in Jamaica , Hispaniola, and, disjunct, Dominica, Martinique, St. Lucia and St Vincent. Ricklefs & Bermingham (Am. Nat. 163, 227-239. 2004) found this distribution 'unexplainable', but they assumed a centre of origin on the mainland. Something is happening here, but they don't know what it is...

Michael Heads

Wellington, New Zealand .

My papers on biogeography are at: http://tiny.cc/RiUE0

--- On Mon, 6/29/09, John Grehan <jgrehan at sciencebuff.org> wrote:


From: John Grehan <jgrehan at sciencebuff.org>
Subject: Re: [Taxacom] panbiogeography critique
To: "Fet, Victor" <fet at marshall.edu>, mivie at montana.edu
Cc: taxacom at mailman.nhm.ku.edu
Date: Monday, June 29, 2009, 7:31 AM


Yes, and Croizat was extremely anticommunist and apparently anti
anything coming close to it.

John Grehan

> -----Original Message-----
> From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-
> bounces at mailman.nhm.ku.edu] On Behalf Of Fet, Victor
> Sent: Sunday, June 28, 2009 3:25 PM
> To: mivie at montana.edu
> Cc: taxacom at mailman.nhm.ku.edu
> Subject: Re: [Taxacom] panbiogeography critique
> 
> >>>>>>No, it is you who miss the point, I specifically included Leon
as
> non-comparable. If you want someone to compare to, Trofim Lysenko is
a
> better example given the players.
> 
> 
> Dr. Ivie - can I politely cut into the exciting fray and vehemently
object
> to your overreaching comparisons?
> 
> Lysenko, whose name may be less known to the young people on the
Taxacom,
> besides being a quack, was an avid and criminal henchman of a dictator
> Stalin, personally guilty in suppression, misery, exile, imprisonment
and
> death of thousands of people, including my late teacher Yuli Kerkis.
> 
> Croizat should not be even remotely compared to such "players" even in
> jest (and I doubt that he would join Hugo Chvez to offer a Bolivarist
> biology).
> 
> Victor Fet
> Marshall University
> _______________________________________________
> 
> Taxacom Mailing List
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> 
> The Taxacom archive going back to 1992 may be searched with either of
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> 
> (1) http://taxacom.markmail.org
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