Phylogenetic position of the langur genera Semnopithecus and Trachypithecus among Asian colobines, and genus affiliations of their species groups

Abstract

BackgroundThe evolutionary history of the Asian colobines is less understood. Although monophyly of the odd-nosed monkeys was recently confirmed, the relationships among the langur genera Presbytis, Semnopithecus and Trachypithecus and their position among Asian colobines remained unclear. Moreover, in Trachypithecus various species groups are recognized, but their affiliations are still disputed. To address these issues, mitochondrial and Y chromosomal sequence data were phylogenetically related and combined with presence/absence analyses of retroposon integrations.ResultsThe analysed 5 kb fragment of the mitochondrial genome allows no resolution of the phylogenetic relationships among langur genera, but five retroposon integrations were detected which link Trachypithecus and Semnopithecus. According to Y chromosomal data and a 573 bp fragment of the mitochondrial cytochrome b gene, a common origin of the species groups T. [cristatus], T. [obscurus] and T. [francoisi] and their reciprocal monophyly is supported, which is also underpinned by an orthologous retroposon insertion. T. [vetulus] clusters within Semnopithecus, which is confirmed by two retroposon integrations. Moreover, this species group is paraphyletic, with T. vetulus forming a clade with the Sri Lankan, and T. johnii with the South Indian form of S. entellus. Incongruence between gene trees was detected for T. [pileatus], in that Y chromosomal data link it with T. [cristatus], T. [obscurus] and T. [francoisi], whereas mitochondrial data affiliates it with the Semnopithecus clade.ConclusionNeither relationships among the three langur genera nor their position within Asian colobines can be settled with 5 kb mitochondrial sequence data, but retroposon integrations confirm at least a common origin of Semnopithecus and Trachypithecus. According to Y chromosomal and 573 bp mitochondrial sequence data, T. [cristatus], T. [obscurus] and T. [francoisi] represent true members of the genus Trachypithecus, whereas T. [vetulus] clusters within Semnopithecus. Due to paraphyly of T. [vetulus] and polyphyly of Semnopithecus, a split of the genus into three species groups (S. entellus - North India, S. entellus - South India + T. johnii, S. entellus - Sri Lanka + T. vetulus) seems to be appropriate. T. [pileatus] posses an intermediate position between both genera, indicating that the species group might be the result of ancestral hybridization.

Bringing Up Baby: Developmental Simulation of the Adult Cranial Morphology of Rungwecebus Kipunji

“…Additionally, the kipunji cranium offers no evidence of hybrid ancestry. But there is no reason to expect classic hybrid traits (e.g., supernumerary teeth; Ackermann et al, 2006) in a lineage that has had thousands of generations to weed out conflicts between its parental genomes, as witnessed by the fact that the kipunji and other such suspected hybrid taxa have been identified solely on the basis of their DNA (Tosi et al, 2000;Sinha et al, 2005;Chakraborty et al, 2007;Karanth, 2008;Karanth et al, 2008;Osterholz et al, 2008;Burrell et al, 2009;Zinner et al, 2009). …”

“…Several cercopithecid species are thought to have arisen through intrageneric introgression (Tosi et al, 2000;Chakraborty et al, 2007;Osterholz et al, 2008), and intergeneric hybridization has been reported in both captivity and (less frequently) the wild (Markarian et al, 1972;Chiarelli, 1973;Dunbar and Dunbar, 1974;Jolly et al, 1997). Like the kipunji, the golden and capped leaf monkeys (Trachypithecus geei and T. pileatus) of South Asia are proposed to have arisen through intergeneric hybridization between Semnopithecus and Trachypithecus (Karanth, 2008;Karanth et al, 2008;Osterholz et al, 2008). These cases suggest that natural hybridization has been more important in Old World monkey evolution than previously thought (Arnold and Meyer, 2006) and also raise interesting questions for taxonomists.…”

Summary of phylogeny in subfamily Colobinae (Primate: Cercopithecidae)

“…Though the monophyly of the odd-nosed monkey group has been unambiguously established from previous studies of both morphology and geographical distribution [1,11,12,14,60] and confirmed by genetic data [17][18][19]26,30,31,52], there had long been controversy over the relationships among the genera within this group. It was especially the case that among Pygathrix, Rhinopithecus and Nasalis (Figure 3) [17][18][19]26,30,31,48].…”

“…Trachypithecus is the largest and most diverse genus of Asian Presbytina with a widest distribution, ranging from South India and Sri Lanka through mainland Southeast Asia to the Sundaland [52]. Within genus Trachypithecus, one species that had long been considered hard to determine phylogenetically is T. pileatus (the capped langur).…”

“…Therefore, phylogenetic relationships within Asian colobines, including those among genera and some species had been disputed hotly in previous studies and were not well established yet [1,[17][18][19]25,26,[29][30][31][49][50][51][52][53][54][55][56][57][58][59].…”