Geography Reference
In-Depth Information
Algorithm
The algorithm consists of the following steps (Nelson and
Ladiges 1996):
1. Obtain the taxonomic cladograms of the taxa distributed in the areas ana-
lyzed.
2. Replace the terminal taxa from the taxonomic cladograms with the areas
inhabited by them to obtain taxon-area cladograms.
3. Resolve widespread taxa with the transparent method.
4. Identify the paralogy-free subtrees starting at each terminal node and pro-
gressing to the base of each taxon-area cladogram. When a node leads
to one or more terminal taxa that are geographically widespread and part
of that distribution overlaps with that of another taxon or taxa, reduce the
widespread distribution to the nonoverlapping geographic element.
5. Represent the nodes of all the paralogy-free subtrees in a component or
three-item matrix.
6. Analyze the data matrix with a parsimony algorithm to obtain the general
area cladograms.
Empirical Applications
Brown et al. (2006), Contreras-Medina et al.
(2007b), Giribet and Edgecombe (2006), Ladiges et al. (1997), Lattke
(2003), Linder (1999), Morrone and Coscarón (1998), Morrone and Urtubey
(1997), Morrone et al. (1997), Nelson and Ladiges (1996, 2001), Roig-
Juñent et al. (2003, 2006), and Zhang et al. (2002).
Software
TASS (Nelson and Ladiges 1995) and Nelson05 (Cao and Ducas-
se 2005).
The Andes are the most important mountainous system of South America. Clas-
sically, they have been divided into the Austral Andes (54°-18° south latitude),
Central Andes (18°-3°), and Northern Andes (3°-10°). The Northern Andes run
from northern Venezuela to southern Ecuador, and despite having different types
of vegetation (superpáramo, páramo, subpáramo, and forest), they were treated
as a biogeographic unit by Morrone (1994a, 1996b). From the biogeographic
point of view they are very interesting because they have numerous endemic
taxa and complex distributional patterns, and their most austral part, the Amo-
tape-Huancabamba zone of southern Ecuador, is transitional between the North-
