Geography Reference
In-Depth Information
Figure 5.9
Primary Brooks parsimony analysis. (a-d) Taxon-area cladograms and
matrices derived from them: (a) trivial case; (b) taxon with a missing area; (c) wide-
spread taxon; (d) taxon with a redundant distribution; (e) data matrix with all the in-
formation; (f) general area cladogram obtained. AF, Africa; AUS, Australia; NA, North
America; SA, South America.
Four conventions are followed in secondary BPA (Brooks 2004):
• Assumption 0: All species and their distributions in each cladogram
must be dealt with without modification, and the result must be logic-
ally consistent with all input data.
• Missing data coding: All cases of absence should be coded a priori
as missing (“?”), which requires a posteriori interpretations to provide
most parsimonious explanations of primitive absences (no member of
the clade was ever in the area) or extinctions (secondary loss of a
member of a clade).
• Area duplication: Whenever areas have reticulate histories with re-
spect to the species inhabiting them, assumption 0 will be violated un-
less these areas are represented as separate entities for each separ-
