Geography Reference
In-Depth Information
Testing
Relationships
Between
Because the generalized tracks that result from panbiogeographic analyses
are unrooted, they connect geographic areas but do not specify a precise se-
quence of fragmentation. For example, given a generalized track joining Aus-
tralia, New Zealand, and Chile, which of the three areas first separated from
the others? In order to determine this sequence, phylogenetic data must be
incorporated. In this chapter I present the basic approach of cladistic biogeo-
graphy, introduce some methods, and provide case studies.
This approach assumes a correspondence between the phylogenetic rela-
tionships of the taxa and the relationships between the areas they inhabit
(Nelson and Platnick 1980, 1981; Platnick and Nelson 1978). Cladistic
biogeography uses information on the cladistic relationships between the
taxa and their geographic distribution to form hypotheses on the relationships
between areas. If several taxa show the same pattern, such congruence is
evidence of common history (Crisci and Morrone 1992; Crisci et al. 2000;
Ebach and Humphries 2002; Enghoff 1996; Humphries and Parenti 1999;
Humphries et al. 1988; Morrone 1997; Morrone and Crisci 1995; Sanmartín
and Ronquist 2002; Wiley 1988a; Zunino and Zullini 1995). We may char-
acterize cladistic biogeography considering that it originated from the joining
of three largely independent research programs: Hennig's (1950) phylogen-
etic systematics, Croizat's (1958b, 1964) panbiogeography, and Wegener's
(1929) continental drift. To them, Nelson and Platnick (1981) added the de-
ductive-hypothetical method of Popper (1959, 1963).
