Geography Reference
In-Depth Information
three taxa for which cladograms were available, which consisted of fifty-four an-
imal taxa and nineteen plant taxa (the fungus genus
Cyttaria
was included in
this group because of similar means of dispersal). Areas analyzed corresponded
mainly to historically persistent Gondwanan landmasses: Africa (excluding the re-
gion north of the Saharan belt), Madagascar (including the Seychelles, Reunion,
and Mauritius), India (including Nepal, Tibet, and Sri Lanka), Australia (including
Tasmania), New Zealand, New Caledonia, New Guinea, southern South Amer-
ica (the southern temperate region), northern South America (the northern trop-
ical region), southeast Asia (including the Malaysian peninsula, Philippines, Su-
matra, and Borneo), southwest Pacific (Melanesian archipelagos), and the Holarc-
tic (Palearctic and Nearctic regions). The authors applied tree reconciliation ana-
lysis with TreeFitter version 1.3 (Ronquist 2002).
Sanmartín and Ronquist (2004) obtained best optimal general area clado-
(
fig. 5.17h
)
, the noninsect animals (
fig. 5.17i
)
, and the plants (
fig. 5.17j
). These
four general area cladograms were significant in terms of overall cost and had a
higher number of vicariance events than expected by chance (
p
= .01 for the plant
data set and
p
< .01 for the others). The cladogram based on animals (
fig. 5.17g
)
agrees with the southern Gondwana pattern, except for the position of Africa. The
same cladogram was obtained when insects were analyzed separately, but when
the Eucnemidae were excluded from the data set, the southern Gondwana pat-
tern became complete in that it also included Africa (
fig. 5.17h
). The analysis of
the animal taxa excluding insects also reflected the southern Gondwana pattern
(
fig. 5.17i
)
. In contrast, the plant area cladogram (
fig. 5.17j
)
supported the plant
southern pattern. Both animal and plant cladograms supported a hybrid origin of
South America (Crisci et al. 1991b): Northern South America was grouped with
the Holarctic region, and southern South America appeared more closely related
to Australia or New Zealand.
