Pleistocene glacial cycle effects on the phylogeography of the Chinese endemic bat species, Myotis davidii

Abstract

Background: Global climatic oscillations, glaciation cycles and the unique geographic topology of China have profoundly influenced species population distributions. In most species, contemporary distributions of populations cannot be fully understood, except in a historical context. Complex patterns of Pleistocene glaciations, as well as other physiographic changes have influenced the distribution of bat species in China. Until this study, there had been no phylogeographical research on Myotis davidii, an endemic Chinese bat. We used a combination of nuclear and mitochondrial DNA markers to investigate genetic diversity, population structure, and the demographic history of M. davidii. In particular, we compared patterns of genetic variation to glacial oscillations, topography, and environmental variation during the Pleistocene in an effort to explain current distributions in light of these historical processes.Results: M. davidii comprises three lineages (MEP, SWP and SH) based on the results of molecular variance analysis (AMOVA) and phylogenetic analyses. The results of a STRUCTURE analysis reveal multi-hierarchical population structure in M. davidii. Nuclear and mitochondrial genetic markers reveal different levels of gene flow among populations. In the case of mtDNA, populations adhere to an isolation-by-distance model, whereas the individual assignment test reveals considerable gene flow between populations. MDIV analysis indicate that the split of the MEP and SWP/SH lineages, and from the SWP and SH lineages were at 201 ka BP and 158 ka BP, respectively. The results of a mismatch distribution analysis and neutrality tests indicate a population expansion event at 79.17 ka BP and 69.12 ka BP in MEP and SWP, respectively. Conclusions:The complex demographic history, discontinuous extant distribution of haplotypes, and multiplehierarchy population structure of M. davidii appear associated with climatic oscillations, topography and ecoenvironmental variation of China. Additionally, the three regions are genetically differentiated from one another in the entire sample set. The degree of genetic differentiation, based on the analysis of mtDNA and nDNA, suggests a malemediated gene flow among populations. Refuges were in the MEP, SH and the lower elevations of SWP regions. This study also provides insights for conservation management units (MEP, SWP and SH). BackgroundGlobal climatic oscillations and associated glaciation cycles have profoundly influenced species population distributions [1]. Pleistocene climate oscillations have contributed to the genetic structure of current species [2] and have played an important role in initiating intra-specific divergences of North American animal taxa [3].

Lineage Divergence and Historical Gene Flow in the Chinese Horseshoe Bat (Rhinolophus sinicus)

“…Evidence for refugia in the east and southwestern plateaus of China has been reported by previous phylogeographic studies, e.g. in frogs [13] and in bats [14], [15]. In our study, a refugium in the southwest is indicated by high nuclear diversity observed in septentrionalis, and one in the East by both high mtDNA diversity and an ancient TMRCA estimate for bats in this region.…”

“…This phenomenon had major consequences for latitudinal climatic clines between the east and the west of East Asia [16], and led to the formation of three marked altitudinal steps that also correspond to different ecological zones (see Figure 1 in ref. [15]). Relating this topography to our focal populations, septentrionalis corresponds to the edge of step 1, the Central sinicus population to step 2, and the East sinicus population to step 3.…”

“…Recent studies have shown that Pleistocene climatic fluctuations and associated sea level changes have contributed to intraspecific diversification of many taxa from East Asia [12], [13]. Several refugia have been reported in the east and southwestern plateau of China [13], [14], [15], which appear to have promoted population divergence and speciation [10]. In addition to global climate cycles, the biota of East Asian was further impacted by severe climatic and environmental changes due to the uplift of the Qinghai-Tibetan Plateau (QTP).…”

Phylogeography of the Rickett’s big-footed bat, Myotis pilosus(Chiroptera: Vespertilionidae): a novel pattern of genetic structure of bats in China

“…These population genetic structures were also supported by the results of an AMOVA with 69.56% variation among regions (Table 2). Population genetic structure was generally consistent with the known macro-ecological characteristics, with individuals from populations with similar vegetation types, temperature, precipitation and topography recovered in the same lineage [7,18]. The pattern of subdivision into subpopulations could be explained by the influence of environmental characteristics during an extended period of time, and especially be reflected in mtDNA.…”

Reflection of paleoclimate oscillations and tectonic events in the phylogeography of moustache toads in southern China

“…Therefore, they would escape from warmer areas by moving toward the top of mountains, which enhanced geological isolation and genetic divergence among lineages. However, previous studies on species in southern China failed to detect such effects of pre‐Pleistocene climate changes on the phylogeographic pattern (You et al ., ; Zhan et al ., ). One of the reasons is that the evolutionary history of these species is too young to detect long‐term legacies from their genome.…”