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[Taxacom] Panbiogeography

Michael Heads m.j.heads at gmail.com
Thu Apr 3 16:39:23 CDT 2014 

Hi Ken,

The aplocheiloid killifish illustrate a standard pattern, with two main
clades (Fig. 2-3 in my 2012 book). One is in America, and (another
subclade) mainland Africa. It's not in Madagascar, and you might
assume that this was the result of extinction there. But the other main
clade is in Madagascar and the Seychelles, and also (another
subclade) from India to Java.

You could explain the pattern by chance dispersal from anywhere within the
whole range, e.g. Guatemala or Gabon or Goa. Chance dispersal is not
related to any other factor, and so this wouldn't make any particular
predictions.

As an alternative, both groups could have been everywhere to begin with,
and you could explain the pattern by the chance extinction of the first
group from Madagascar - Java, and the chance extinction of the second group
from America and Africa. This would predict fossils in the area of absence,
but none have ever been found. It's also difficult to imagine why one group
would go extinct in an area that is exactly allopatric with the area where
the other group went extinct. This explanation also leaves the original
differentiation of the groups unaccounted for.

Or you could explain the pattern by simple vicariance, with the first break
located between Africa and Madagascar, at the Mozambique Channel. This
would make the general predictions that other groups would show similar
patterns, and that there would be a simple correlation between the pattern
and tectonics, climate or some other environmental factor. Note that the
first break, between Africa and Madagascar, comes before the secondary
breaks (between America and Africa, and between Madagascar-Seychelles, and
India - Java). This is congruent with the continental breakup sequence.

Michael



On Thu, Apr 3, 2014 at 11:17 AM, Ken Kinman <kinman at hotmail.com> wrote:

> Hi Juerg,
>        Well, certainly not a nude rock.  However, as I explained in an
> earlier posting, the end-Cretaceous extinction wiped out a lot of taxa
> (most vertebrates and probably all mammals).  This left it with a lot of
> empty niches which new mammals and birds, etc. would fill during the
> early-to-mid Tertiary.
>         But I suppose John would deny that the end-Cretaceous extinction
> was that bad in Madagascar.  I am giving up arguing with him about
> Madagascar, because he just repeats the same old fallback positions, and
> now claiming that there is no "analytical evidence" for dispersal to
> Madagascar.  It might not be strictly analytical evidence according his
> definition of analytical, but there is plenty of evidence.  He simply
> refuses to accept any of it.   I should have given up trying to reason with
> him a long time ago.
>                       -------------------Ken Kinman
>
> -----------------------------------------------------------------------------------------------------
> > From: demarmjc at hotmail.com
> > To: taxacom at mailman.nhm.ku.edu
> > Date: Wed, 2 Apr 2014 17:00:29 -0400
> > Subject: Re: [Taxacom] Panbiogeography
> >
> > Seeing the comments by our dispersalist friends, I wonder then, whether
> Madagascar was empty, a piece of nude rock, before the "great migration"
> out of Africa?
> > Juerg De Marmels
> >
> > > Date: Thu, 3 Apr 2014 05:20:57 +1300
> > > From: calabar.john at gmail.com
> > > To: kinman at hotmail.com
> > > CC: taxacom at mailman.nhm.ku.edu
> > > Subject: Re: [Taxacom] Panbiogeography
> > >
> > > What is baffling is that Ken continues to assert a falsehood - that the
> > > importance of dispersal is minimized in panbiogeography. Reminds me a
> bit
> > > of American politics (perhaps politics in general) that if something is
> > > claimed often enough it must be true. It is not. Hence the key
> > > panbiogeographic formulation: dispersal = translation in space + form
> > > making.
> > >
> > > As for Madagascar, it is not about whether or not dispersal occurred,
> but
> > > under what circumstances. Claims that much or all of the biota
> originated
> > > via chance overwater dispersal from Africa may be reasonable as a
> > > conjecture, but there is no analytic evidence in support (and molecular
> > > divergence estimates based on fossil or island ages, no matter how
> recent,
> > > do not .preclude earlier events involving continuity of land).
> > >
> > >
> > > John Grehan
> > >
> > >
> > > On Thu, Apr 3, 2014 at 2:20 AM, Ken Kinman <kinman at hotmail.com> wrote:
> > >
> > > > Hi Jason,
> > > >         Thanks for passing along that weblink.  It baffles me that
> John
> > > > and Michael continue to minimize the importance of dispersal,
> especially
> > > > when it comes to Madagascar.  The real question in my mind on that
> subject
> > > > is not whether rafting was the major factor, but how that rafting was
> > > > caused.  Was it massive river flooding in adjacent Africa washing
> large
> > > > rafts of vegetation (and any fauna that hitched a ride) into the
> ocean, or
> > > > was it tsunamis doing the same thing?  Perhaps both, although in the
> case
> > > > of Madagascar, I would tend to favor river flooding over tsunamis.
>  On the
> > > > other hand, dispersal over longer distances (as in the Pacific) might
> > > > require much larger rafts of vegetation, and tsunamis would be
> better at
> > > > producing the rare monster rafts containing a very large number of
> trees
> > > > tangled together.
> > > >                 ---------------------Ken Kinman
> > > >
> > > >
> ---------------------------------------------------------------------------------------------------
> > > > > Date: Tue, 1 Apr 2014 00:54:51 +0200
> > > > > From: aphodiinaemate at gmail.com
> > > > > To: taxacom at mailman.nhm.ku.edu
> > > > > Subject: Re: [Taxacom] Panbiogeography
> > > > >
> > > > > What do you know, Rupert sent me this link regarding potential
> ocean
> > > > > dispersal resulting from the Tohoku earthquake:
> > > > >
> > > > > http://dx.doi.org/10.1038/495013a
> > > > >
> > > > > This surely qualifies as a "black-swan" event, also known as
> "chance"
> > > > > (not the probability concept mind you,) ;) .
> > > > >
> > > > > Best
> > > > >
> > > > > Jason
> > > > >
> > > > > On 28 March 2014 21:51, Stephen Thorpe <stephen_thorpe at yahoo.co.nz
> >
> > > > wrote:
> > > > > > Dispersal can also occur passively, by rafting on floating
> chunks of
> > > > > > habitat, or phoresy on other animals
> > > > > > From: JF Mate <aphodiinaemate at gmail.com>
> > > > > > To: Taxacom <taxacom at mailman.nhm.ku.edu>
> > > > > > Sent: Saturday, 29 March 2014 9:43 AM
> > > > > > Subject: Re: [Taxacom] Panbiogeography
> > > > > >
> > > > > > Dear John
> > > > > >
> > > > > > after looking at you replies I have realised that we are chasing
> each
> > > > > > other in circles and that you constantly refer to Michael?s book
> when
> > > > > > I seek a more concrete answer. This makes it rather difficult and
> > > > > > unproductive. So, I will simply state the following definitions
> under
> > > > > > which I operate:
> > > > > >
> > > > > >
> > > > > > -Dispersal: change in location. The difference between long
> range and
> > > > > > short range is merely in the probability of each resulting in
> > > > > > successful (i.e. surviving and reproducing). "Short" and "long"
> are
> > > > > > taxon and site specific.
> > > > > >
> > > > > > -Barrier: impediment to movement. When I defined what a barrier
> was I
> > > > > > failed to consider partial blockage but instead opted for a
> binary
> > > > > > barrier. I see this was a mistake on my part, so I hope this will
> > > > > > clear the matter.
> > > > > >
> > > > > >
> > > > > > Dispersal by insects >100Km from the source (mostly coastline)
> are
> > > > > > very common, even when flying a few meters above the surface.
> > > > > > Transoceanic flights by large, easily noticed insects (mostly
> > > > > > butterflies) have been documented several times in recent times.
> > > > > > Considering that there are observed examples of organisms
> dispersing
> > > > > > beyond barriers (usually crossing bodies of water) I think
> dispersal
> > > > > > is a valid mechanism.
> > > > > >
> > > > > > Furthermore the lack of genetic structure in many insect
> species, even
> > > > > > in discontinuous ranges spanning thousands of kilometers
> indicates a
> > > > > > fair degree of dispersal. Granted that the opposite is true and
> > > > > > particularly striking examples are common (headwater stream
> insects
> > > > > > for example). But since examples from both mechanisms can be
> found, I
> > > > > > don?t feel this somehow disproves the other.
> > > > > >
> > > > > > As to your statements, I feel a couple are inconsistent. I would
> be
> > > > > > grateful for a clearer explanation:
> > > > > >
> > > > > > "... but when there is a biogeographic break correlated with a
> > > > > > tectonic break there is reason to consider that they are
> related. ...
> > > > > > The panbiogeographic method is about pattern analysis. In
> principle,
> > > > > > distribution data provide an empirical resource. Speculations
> about
> > > > > > imagined chance dispersal does not."
> > > > > > So what happens when a biogeographic break and a tectonic one do
> not
> > > > > > coincide? Furthermore, correlation is not necessarily causation,
> so
> > > > > > don't panbiogeographers also speculate?
> > > > > >
> > > > > > "No, the patterns make the theory problematic as the patterns are
> > > > > > incongruous with the expectations of chance dispersal. ...
> However you
> > > > > > chose your words, the point is that panbiogeographic analysis
> shows
> > > > > > that distance is not a predictor of distribution range for
> > > > > > differentiated taxa so the 'probabilities' are contingent upon
> the
> > > > > > relevant factors of geological, climatic, or human disruption.'
> > > > > > If dispersal is random, the result of the interaction of numerous
> > > > > > factors, is it suprising that simply using one (distance) doesn't
> > > > > > work? An island may be upwind and therefore rarely receive flying
> > > > > > insects from the minland whereas a more distant, downwind island
> can
> > > > > > receive a fairly constant rain of wind-carried organisms.
> Gillespie et
> > > > > > al provide a nice review.
> > > > > >
> > > > > > "When it comes down to explaining vicariant patterns the
> principal
> > > > > > choice has been to frame the origin in terms of dispersal from
> centers
> > > > > > of origin."
> > > > > > I feel otherwise.Can you please support this argument?
> > > > > >
> > > > > > Best
> > > > > >
> > > > > >
> > > > > > Jason
> > > > > >
> > > > > > _______________________________________________
> > > > > > Taxacom Mailing List
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> > > > > > The Taxacom Archive back to 1992 may be searched at:
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> > > > > >
> > > > > >
> > > > > > Celebrating 27 years of Taxacom in 2014.
> > > > > >
> > > > > >
> > > > >
> > > > > _______________________________________________
> > > > > Taxacom Mailing List
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> > > > > The Taxacom Archive back to 1992 may be searched at:
> > > > http://taxacom.markmail.org
> > > > >
> > > > > Celebrating 27 years of Taxacom in 2014.
> > > >
> > > > _______________________________________________
> > > > Taxacom Mailing List
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> > > > http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
> > > > The Taxacom Archive back to 1992 may be searched at:
> > > > http://taxacom.markmail.org
> > > >
> > > > Celebrating 27 years of Taxacom in 2014.
> > > >
> > > _______________________________________________
> > > Taxacom Mailing List
> > > Taxacom at mailman.nhm.ku.edu
> > > http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
> > > The Taxacom Archive back to 1992 may be searched at:
> http://taxacom.markmail.org
> > >
> > > Celebrating 27 years of Taxacom in 2014.
> >
> > _______________________________________________
> > Taxacom Mailing List
> > Taxacom at mailman.nhm.ku.edu
> > http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
> > The Taxacom Archive back to 1992 may be searched at:
> http://taxacom.markmail.org
> >
> > Celebrating 27 years of Taxacom in 2014.
>
> _______________________________________________
> Taxacom Mailing List
> Taxacom at mailman.nhm.ku.edu
> http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
> The Taxacom Archive back to 1992 may be searched at:
> http://taxacom.markmail.org
>
> Celebrating 27 years of Taxacom in 2014.
>



-- 
Dunedin, New Zealand.

My recent books:

*Molecular panbiogeography of the tropics.* 2012. University of California
Press, Berkeley. www.ucpress.edu/book.php?isbn—80520271968

*Biogeography of Australasia:  A molecular analysis*. 2014. Cambridge
University Press, Cambridge. www.cambridge.org/9781107041028

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