Geography Reference
In-Depth Information
amounting to an a priori parsimony criterion. This reflects the ontology of
simplicity. Phylogenetic biogeography falsifies the null hypothesis of a vicari-
ance explanation when the data do not support it, amounting to an a posteri-
ori parsimony criterion. Data that appear to conflict with the null hypothesis
indicate that it is flawed, determining a posteriori the minimum number of
falsifications that are necessary to explain all the data. This reflects the on-
tology of complexity.
Humphries and Ebach (2004) postulated that the dichotomy between
cladistic and phylogenetic biogeographies has to do with the interpretation
of cladograms as homology-based hierarchies or as phylogenetic trees, re-
spectively. This interpretation can be extended to other approaches that
also treat cladograms as phylogenetic trees: ancestral area analysis and
intraspecific phylogeography. In this respect, it would be pertinent to refer
to O'Hara's (1988) distinction between chronicle and history. A chronicle is
a description of a series of events, arranged in chronological order, and
not accompanied by any causal statements or explanations, whereas a his-
tory contains statements about causal connections. Cladistic biogeography
estimates a chronicle, and phylogenetic biogeography estimates a history.
Another way to distinguish both groups of methods is to apply the distinction
between the philosophical positions of reciprocal illumination and total evid-
ence (Rieppel 2004). A posteriori methods work under the principle of re-
ciprocal illumination (Hennig 1950), searching for consilience or congruence
between data from different taxa. A priori methods work under the principle
of total evidence (Kluge 1989), relying on the largest set of data analyzed
simultaneously.
I am unconvinced of the existence of two different research programs
(Ebach and Morrone 2005; Morrone 2005a). Although the distinction
between the two groups of methods is valid, I suggest that they still can
be considered to implement cladistic biogeography. The question of which
method to apply is not easy to answer; all have their supporters and their
critics. A practical approach is to apply more than one and then compare the
differences between the results obtained (Contreras-Medina et al. 2007b).
Brooks, D. R. 1990. Parsimony analysis in historical biogeography and co-
evolution: Methodological and theoretical update.
Systematic Zoology
39:14-30.
