Identification of Biotic Components - Evolutionary Biogeography - page 76

• The spatial and temporal component of these distributional patterns
can be represented graphically.
• Testable hypotheses about historical relationships between the evolu-
tion of distributions and Earth history can be derived from geographic
correlations between distribution graphs and geological or geomorphic
features.
With regard to the relevance of panbiogeography for evolutionary bio-
logy, Grehan (1988b) postulated that the fusion of space, time, and form im-
plies the recognition of a single evolutionary process, where “organism” and
“environment” are not isolated entities. Classically, the absolute separation
of organisms and environments has been reflected in the search for mech-
anisms or forces acting on passive organisms (natural selection) or passive
environments (orthogenesis). Panbiogeography assumes that taxa exist as
part of their environments and vice versa; they are coconstructed, so mech-
anisms should be focused on the relationship itself rather than on the or-
ganisms or the environment. This “constructivist interaction” (Oyama 2000)
provides a conceptual framework for the development of a new synthesis in
evolutionary biology, where the disciplines that contribute to it can derive in-
sight from the others.
A panbiogeographic analysis comprises three basic steps ( fig. 4.1 ) :
1. Construct individual tracks for two or more different taxa ( fig. 4.1a - 4.1f ) .
2. Obtain generalized tracks based on the comparison of the individual tracks
( fig. 4.1g ) .
3. Identify nodes in the areas where two or more generalized tracks intersect
( fig. 4.1h ) .