Testing Relationships Between Biotic Components - Evolutionary Biogeography - page 196

Software TAS (Nelson and Ladiges 1991b), which implements assumptions
0 and 1. The matrix obtained may be analyzed with any parsimony or com-
patibility algorithm.
Empirical Applications de Meyer (1996), Ladiges et al. (1992), Morrone
(1993b), Morrone and Carpenter (1994), Morrone et al. (1994, 1997), van
Soest and Hajdu (1997), and van Veller et al. (2000).
CASE STUDY 5.4 Cladistic Biogeography of the “Blue Ash” Euca-
lypts
The twenty-three species of the plant genus Eucalyptus known as “blue ash” con-
stitute a clade distributed in southeastern Australia. Ladiges et al. (1992) under-
took their cladistic analysis and based on the cladogram obtained presented a re-
solved area cladogram using the three area statement approach.
Ladiges et al. (1992) obtained the three area statements under assumptions 0,
1, and 2 and used Hennig86 (Farris 1988) for the parsimony analysis of the data
matrices. Additionally, they performed a BPA. The authors represented the distri-
butional areas of the species analyzed on maps, and on the basis of their coin-
cidence they identified twelve areas of endemism ( fig. 5.14a ). After replacing the
terminal species in the consensus cladogram with these areas of endemism, they
found some areas repeated across major clades, which were taken as evidence
of geographic paralogy. They concluded that three orthologous clades were ap-
propriate units for the analysis: E. stenostoma-E. haemostoma, E. stellulata, and
E. fraxinoides groups. The E. stenostoma-E. haemostoma group ( fig. 5.14b ) , un-
der assumption 1 generated 160 three area statements, which produced twelve
equally parsimonious cladograms (consensus cladogram in fig. 5.14c ). Adding 111
three area statements for widespread taxa (assumption 0) resulted in a single
most parsimonious cladogram ( fig. 5.14d ) . BPA resulted in seven cladograms
(consensus cladogram in fig. 5.14e ). Resolution by hand of assumption 2, accept-
ing the position of E 1 as resolved by assumption 1, is presented in fig. 5.14f . The
taxon-area cladograms of the E. stellulata and E. fraxinoides groups ( figs. 5.14g
and 5.14h ) are easier to interpret. The former suggests that E 2 is at the root of that
cladogram, whereas the latter suggests that G is related to E 1 . Adding them to the
cladogram in fig. 5.14d gave a resolved area cladogram ( fig. 5.14i ) for the “blue
ash” clade, where E 2 had two alternative positions, and areas F and A were not
considered.
On the basis of the area cladogram obtained, Ladiges et al. (1992) suggested
a historical sequence in which area H, the southern New South Wales (NSW) es-
carpment, differentiated first from the remaining areas in southeastern Australia,
although differentiation of Mount Buffalo, Victoria (E 2 ) may have been even earlier.