Recently, two phylogenetic studies using molecular characters confirmed that the associations between species-groups based on morphological similarities are similar to those based on molecular characters [14], [15].
About half of the parsimony-informative molecular characters account for this difference between these two diploid species.
Depending on the length of time since divergence, only some fraction of phenotypic and molecular characters may have become fixed between incipient species.
While this conflict between morphological and molecular characters can be readily accounted for by the morphological reductionism resulting from the parasitic lifestyle of Buddenbrockia, no such accounting can explain the suite of morphological characters shared among Platyhelminthes [2].
An important practical consequence of introgression is that conflicts between morphological or molecular characters in phylogenetic reconstruction may sometimes be explained by gene transfer as well as by parallel evolution and errors in phylogeny estimation.
In addition to displaying between three and five diagnostic molecular characters relative to M. m. calita, M. m. cotorra, and M. m. monachus (Table 2), the Bolivian luchsi formed a well-supported, monophyletic group based on the mtDNA control region sequence data.
A test of the application of molecular phylogeny in taxonomy is whether there is consistency between classification schemes based on molecular characters and morphological traits.
Indeed, various authors embrace the view that the root lies between archeabacteria and eubacteria because of the few molecular characters that these groups share in common in their genome comparisons (Dagan and Martin 2007; McInerney et al. 2008; Battistuzzi and Hedges 2009; Koonin 2009) but without providing specific molecular analyses to support that view.
a Trees I III show different evolutionary relationships between four hypothetical species (A D); b states for seven molecular characters for the four species.
Earlier, phylogenetic relationship of the genus Panthera was studied using morphological, biochemical as well as molecular characters but it is still debatable and troublesome because of large disparities between these studies.
