[Taxacom] More Map of Life method

John Grehan jgrehan at sciencebuff.org
Fri Nov 19 08:05:55 CST 2010

I appreciate hearing David Kidd's feedback on my comments

I would agree that there is potential interest in mapping phylogenetic
information, but the pertinent question is what kind of mapping and why.
David's method represents an attempt to do this, but the methodological
rationale seem to be tied up with a lot of assumptions about process.

The problem with georeferenced trees as a biogeographic pattern is that
it requires criteria to link biological trees, which have no spatial
information, to distribution localities which also by themselves have no
spatial information. In panbiogeography the link between the two is
manifest in the minimum distance criterion, and phylogenetic
relationship may be used to assign a sequence of linkages, so that it is
possible to identify spatial homologies to combine or distinguish
individual distributions and correlate them with geomorphology. All of
this is simple enough.

Pluralism is often invoked as a goal in biogeography, but such pluralism
is continent upon methodical compatibility, not simply as a rhetorical
device. For example, there is no rationale for integrating
panbiogeography with Darwinian center of origin and dispersal theory,
however pluralistic that might seem. Juan Morrone has indeed attempted
to provide methodolgical links between panbiogeography and area of
endemism analysis, but I would, but I have yet do see this as fully
compatible since areas of endemism, as units of analysis, are arbitrary
constructions (although I am in agreement with Morrone on other aspects
of biogeography.

It was a bit troubling to see Dave repeat some of the misrepresentations
of panbiogeography that are common among opponents, which would be
surprising to hear if he had read panbiogeography. For example, "the
rejection of phylogenetic in preference to taxonomic hypotheses". Where
did that come from? This in particular seems quite bizarre in light of
several of Heads' recent publications that lean heavily on molecular
phylogenies, and especially in that I have just completed a book chapter
in which there is a section on vicariance analysis which provides
explicit examples of phylogenetic applications. And of course time is
never sidelined. To the contrary, Croizat even begins with the argument
that biogeography is all about space and time, and there are correlation
techniques for comparing biogeographic predications on time with other
estimates of the temporal dimension.

As for lack of statistical rigor in identifying congruence between
tracks, one may perhaps always argue this (depending on the threshold of
'rigor'), but it would be a misrepresentation to imply that there are no
statistical methods proposed or applied in panbiogeography. At present
there would seem to me to be more statistical rigor demonstrated for
track analysis that Dave's proposed methodology.

As for confusing terminology - I would be interested to know what is
confusing about the terminology which has been precisely defined in a
number of publications.

And where does this "general rejection of taxon histories" come from?
(And what is meant by this term - narratives about the history of a
group or their phylogenies).

As for an image problem, as I have mentioned before, this appears to be
worse in English-speaking spheres. I attribute this 'problem' (whose
problem?)  to the strong adherence to Darwinian theory in
English-speaking circles, as well as the general dislike of geography by
most practitioners of biogeography who are primarily interested in
biological form (I have indeed seen the eyes of 'biogeographers' glaze
over when shown too many biogeographic maps).

John Grehan

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Kidd, David M
Sent: Friday, November 19, 2010 6:11 AM
To: taxacom at mailman.nhm.ku.edu
Subject: [Taxacom] More Map of Life method

Some thought on John's last message...
I do not advocate a specific methodology, so please don't get hung up on
envelopes and averaging.  You have a tree and some spatial information.
Why not plot a quick envelope geophylogeny to inspect your data just
like you use a box or scatter plot before getting into some serious
hypothesis testing?
Geophylogenies are simply georeferenced trees that may represent extant
biogeographic pattern or alternatively an explicit taxon history. In
retrospect, perhaps 'spatial tree' whould been a more neutral term than
Whichever methodology you prefer, if the result can be represented as a
tree linked to spatial data then it can be represented as a
geophylogeny. If historical biogeographical analysis are made available
as digital representations then different models can be compared in a
spatially explicit environment. The meaning attached to the branchs
connecting nodes will vary with methodology and scientists
interpretation. I personally believe that congruence between models can
be used to make reasonable inferences of history , although these will
always be contingent on further information. For example,  if
phylogeographic pattern, coalescent signitures of population expansion
and ecological niche models all indicate expansion from a glacial
refugia then I believe (for the moment). If the same patterns are found
in other taxa, even better!  As we go back in time evidence will become
more fragmented. I still, however, believe that congruence between
current taxon ranges, present enviro  nmental correlates and past
environmental reconstructions, and fossil ranges provides evidence of
past taxon history.  Morrene's recent attempt to devise conceptual links
between methodologies is, in my opinion, a real step forward towards a
modern pleuralistic approach to historical biogeography. Such a
multifaceted approach will require the direct comparsion of the results
of different methods. Someone in the US should apply for a NESCent
working group/catalysis meeting to futher develop these ideas.
I think exploring the connections between panbiogeography and
geophylogenies is a worthwhile undertaking. I decided not to include the
paragraph on panbiogeography in the paper as I, and others who read
drafts, believe it requires a more detailed discussion than there was
room to accomodate in this paper. This is probably not the place to
start a debate on the merits of panbiogeography versus other historical
biogeographic methods; however, it is clearly not liked by many (I
suspect often as the result of received wisdom, rather than considered
thought). Nevertheless, panbiogeography has a clear image problem, one
reason for which is the rejection of phylogenetic in preference to
taxonomic hypotheses, which also sidelines time. Other problems arise
from a lack of statistical rigour in identifying congrence between
tracks, confusing terminology and a general rejection taxon histories
which interest many others. I do not raise these issues to stimulate a
debate but instead mear  ly to state the contextual background to
discussing panbiogeography.
 - Dave
David M. Kidd

Research Associate
Center for Population Biology
Silwood Park Campus
Imperial College London
0207 594 2470


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