A Revisited Study On Phylogeography And Phylogenetic Diversity Of Myricaria (Tamaricaceae)

Abstract

As the first part of the present study, the ancestral distribution origin of Myricaria at a Eurasian perspective, a genus of Tamaricaceae, was re-evaluated by comparing three different methods, including Statistical Dispersal-Vicariance Analysis (S-DIVA), Dispersal-Extinction-Cladogenesis Analysis (DEC) and Bayesian Binary MCMC Analysis (BBM). In addition, Parsimony Analysis of Endemicity (PAE) was adopted to identify areas of endemism and test whether the endemic areas could be congruent to the origin of distribution. My results showed that two of the three ancestral distribution methods consistently identified East Asia as the historical origin of distribution, which was in line with a previous study using the distributional information of Myricaria in China only based on classical dispersal-vicariance method. PAE further supported such an observation, indicating that PAE could be an option for identifying origin of distribution. Further, it was found that the emigration of Myricaria from East Asia to the rest of Eurasian regions only occurred when the drastic uplifting of Qinghai-Tibet Plateau emerged. As another part of the study, I quantified the phylogenetic diversity patterns of Myricaria species using six phylogenetic diversity metrics, for the purpose of identifying the highest-priority species for conservation. For those species endemic to the origin of distribution, it was found that two species were assigned the highest conservation values under the phylogenetic framework, M. laxiflora and M. elegans var. tsetangensis.