Geography Reference
In-Depth Information
Any attempt to define panbiogeography—the prefix
pan-
(“all”) tries to go
beyond the traditional distinction between phytogeography and zoogeo-
graphy—must contend with a great variety of opinions. Patterson (1983)
considered it “phenetic” because it is based on global similarity. Mayr (1982)
described it as “eccentric.” Nelson (1989) considered panbiogeography an
“evolutionary metatheory.” Stace (1989) defined it as “vicariance in global
distributional patterns.” Grene (1990) considered it “faddish.” For some au-
thors, panbiogeography is simply a precursor of cladistic biogeography (Cox
1998; Grande 1990; Nelson and Platnick 1981; Warren and Crother 2001),
whereas for others it is an alternative research program (Colacino 1997;
Craw and Weston 1984; Espinosa Organista and Llorente Bousquets 1993;
Grehan 2001d; Humphries and Seberg 1989; Morrone et al. 1996; Zunino
and Zullini 1995).
Panbiogeography emphasizes the spatial or geographic dimension of
biodiversity to allow a better understanding of evolutionary patterns and pro-
cesses (Craw et al. 1999). Its main objective is to highlight the relevance of
geographic distributions as direct objects of analysis. The spatial dimension
oforganismsisaprerequisiteforanyevolutionarystudybecausegeography
is the substrate where life occurs. Crisci et al. (2000:48) stated, “Panbiogeo-
graphy is like real estate: the most important thing is location.”
Croizat (1958b, 1964) formulated his approach in terms of three meta-
phors: “Earth and life evolve together,” “space + time + form = the biological
synthesis,” and “life is the uppermost geological layer.” His main objectives
were to establish biogeography as an independent science free from prior
commitments to geological or geophysical theories and to ensure a synthes-
is between biology and geology (Craw and Page 1988). Until the develop-
ment of panbiogeography, biogeographers followed the fashionable geolo-
gical ideas of their times. The lack of a method by which biogeography and
geology could be integrated is illustrated by the cases in which former op-
ponents of continental drift rapidly transferred their models to mobile models
of Earth history.
Panbiogeography is based on four assumptions (Craw et al. 1999):
• Distributional patterns constitute an empirical database for biogeo-
graphic analyses.
• Distributional patterns provide information about where, when, and
how plants and animals evolved.
