284 1993, Myamoto Fitch 1995, Shaffer et al 1991. In this context, as pointed out
by De Queiroz et al 1995, nonindependence within data sets does not necessarily imply functional or physical linkage, but only that characters within a data set are
more likely to share some property relevant for phylogeny estimation than characters in different data sets. Using the support for conflict among trees from
different data sets as a means of assessing such independence de Queiroz 1993, Shaffer et al 1991 can be seen as a test of heterogeneity.
This study showed that morphological datasets indicate contain phylogenetic signal and gene rcbL sequences data showed more phylogenetic
informative characters than morphological data. However gene rbcL sequences data are only provided on 29 species of 69 species of Diplazium that analyzed.
Combining morphological datasets of 69 species with gene rbcL sequences data of 29 species would result more than 50 of missing data on combined matrix data,
and consequently would depict unnatural relationship. Therefore this study did not combine the two datasets and summarized for their phylogenetic concencus. The
short general discussion is given below.
10.2. General Discussion
Phylogenetic analysis of West Malesian Diplazium revealed that the homoplasies characters in Diplazium are high, Homoplasy Index HI = 0.75
Chapter 6. Homoplasies may be resulted from parallelisms, convergence and reversals. Within a cladistic framework homoplasies are also synapomorphies,
they represent derived character transformations defining two or more unrelated groups of taxa. Whereas the “unique” synapomorphies define only a single group.
In the topological tree depicted in Figure 6.8. showed some terminal clades are formed from the unrelated of species or not closely related species, such as clade
that contain that comprises D. hewittii and D. umbrosum, D. esculentum and D. insigne
, D. aquibasale and D. angustipinna. Phylogenetic tree inferred from morphological tree showed that many
terminal clades are comprising of the species that presumed to be closely related by previously author and seems depicting natural relationship although without or
with weak statistical support. For example D. riparium and D. wahauense that
285 presumed to be closely related are in the same tereminal clade. The same
depiction was also showed in the clade that containing D. malaccense,D. sorzogonense
and D. tricholepis, and ‘D. porphyrachis group’. It is indicate that morphological data of Diplazium contain phylogenetic signal although many
characters are polymorphic and homoplastic. Backer et al 1998 stated that morphological datasets contain more phylogenetic signal per characters and can
swamp much larger molecular datasets. Therefore, study that include more morphological characters from living materials as well as anatomical characters,
such as stipe or rachis, would give an inferred phylogenetic tree with strong statically support. As showed at Chapter 4, anatomical characters of stipe give an
indication that the closely related species are showing the similar anatomical characters.
Knowing the status of species, whether originally hybrid or not, that will be included in the phylogenetic analysis of Diplazium is important as many
species of Diplazium are apogamous and they are presumed to be originally hybrids. Because if hybridization has occurred among the species of a taxon
under cladistic analysis the results are varied. Hybridization results in incongruent intersecting data that obscure the underlying hiearachy Funk 1985. All
hyphotheses regarding hybrids identification of course must be corroborated by chromosomal, distributional, and ecological data. Therefore some species of
Diplazium that presumed to be originally hybrids based on result of this, such as
D. procumbens, D. subvirescens , and D. asymmetricum, should be confirmed in
the future study.
10.3. Systematic Implications for the Genus Diplazium
