Geography Reference
In-Depth Information
Humphries and Ebach (2004) analyzed fourteen plant and animal taxon-area
cladograms, taken from Funk and Wagner (1995), with software 3item (Ebach et
al.2005).Additionally,theyusedTASS(NelsonandLadiges1996)toobtainadata
matrix of paralogy-free subtrees under assumption 2 and NONA (Goloboff 1998)
to analyze the matrix.
Area cladistics with 3item and TASS/NONA showed a basally resolved clado-
gram but with a terminal polytomy for Moloka'i, Lana'i, East and West Maui, and
Hawai'i (
fig. 5.23b
)
. When Maui was treated as a single area, TASS/NONA found
a single area cladogram (
fig. 5.23c
)
, which is completely dichotomous, showing
Lana'i and Maui as sister areas. This relationship is consistent with Carlquist's
(1995) reconstruction, where the Maui Nui island complex gave rise to Lana'i and
Moloka'i during the time Hawaii was formed. The divergence of Lana'i and Maui
suggested that the Hawai'i biota was already established on Maui Nui 1 mya
and that the current Maui and Lana'i biotas developed more recently (0.5 mya to
present). The analysis with 3item treating Maui as a single area produced a single
areagram (
fig. 5.23d
)
, where Kaua'i is the sister area to Moloka'i and Hawai'i is
the sister area to Lana'i and Maui. This second analysis suggested a more recent
history (0.5 mya to present) because both main clades match the present current
proximity of the Kaua'i, O'ahu, and Moloka'i biota and of the Hawai'i, Maui, and
Lana'i biota. Humphries and Ebach (2004) concluded that a time slice should be
implemented for the areas. They presented a general areagram (
fig. 5.23e
)
incor-
porating a time slice. This general areagram suggested that two different biotic di-
vergences took place during the formation of the Hawaiian island chain.
