Geography Reference
In-Depth Information
Figure 4.6
Equivalence between areas of endemism and generalized tracks. (a, c,
e) Areas of distribution; (b, d, f) individual tracks; (g) area of endemism; (h) general-
ized track.
Nodes are complex areas where two or more generalized tracks superim-
pose (
fig. 4.5b
). They are usually interpreted as tectonic and biotic conver-
gence zones, areas of ancient geography around which evolution has taken
place (Heads 2004). The recognition of nodes is one of the most import-
ant contributions of panbiogeography. Croizat and his followers have based
many of their critiques to cladistic biogeography on its inability to distinguish
these types of complex areas because of their attachment to the implicit
hierarchy in cladograms. This would not be totally correct because com-
