Recent Geological Events and Intrinsic Behavior Influence the Population Genetic Structure of the Chiru and Tibetan Gazelle on the Tibetan Plateau

Abstract

The extent to which a species responds to environmental changes is mediated not only by extrinsic processes such as time and space, but also by species-specific ecology. The Qinghai-Tibetan Plateau uplifted approximately 3000 m and experienced at least four major glaciations during the Pleistocene epoch in the Quaternary Period. Consequently, the area experienced concurrent changes in geomorphological structure and climate. Two species, the Tibetan antelope (Pantholops hodgsonii, chiru) and Tibetan gazelle (Procapra picticaudata), both are endemic on the Qinghai-Tibetan Plateau, where their habitats overlap, but have different migratory behaviors: the chiru is inclined to have female-biased dispersal with a breeding migration during the calving season; in contrast, Tibetan gazelles are year-round residents and never migrate distantly. By using coalescence methods we compared mitochondrial control region DNA sequences and variation at nine microsatellite loci in these two species. Coalescent simulations indicate that the chiru and Tibetan gazelle do not share concordant patterns in their genealogies. The non-migratory Tibetan gazelle, that is more vulnerable to the impact of drastic geographic changes such as the elevation of the plateau, glaciations and so on, appears to have a strong population genetic structure with complicated demographic history. Specifically, the Tibetan gazelle population appears to have experienced isolation and divergence with population fluctuations since the Middle Pleistocene (0.781 Ma). However, it showed continued decline since the Upper Pleistocene (0.126 Ma), which may be attributed to the irreversible impact of increased human activities on the plateau. In contrast, the migratory chiru appears to have simply experienced population expansion. With substantial gene flow among regional populations, this species shows no historical population isolation and divergence. Thus, this study adds to many empirical studies that show historical and contemporary extrinsic and intrinsic processes shape the recent evolutionary history and population genetic structure of species.

The roles of calving migration and climate change in the formation of the weak genetic structure in the Tibetan antelope (Pantholops hodgsonii)

“…Three haplotype units without spatial clustering were detected based on a phylogeographic analysis of mtDNA sequences. These findings are in agreement with those of previously reported studies (Ruan et al 2005;Zhang et al 2013). However, we found no trait determining the habitat, host and other choices in favor of sympatric divergence among P. hodgsonii populations (Johannesson 2001).…”

“…However, accumulating evidence on P. hodgsonii has suggested that the genetic differentiation among the geographically isolated populations is limited, despite high levels of genetic diversity (Ruan et al 2005;Zhou et al 2007;Du et al 2016). These findings differed from those for other native ungulate populations in the QTP Zhang et al 2013). The calving migration behavior exhibited by P. hodgsonii populations has been suggested to promote genetic exchange between different geographical populations, resulting in the homogenization of the genetic pool (Schaller et al 2005;Du et al 2010).…”

Genetic Resilience of a Once Endangered Species, Tibetan Antelope (Pantholops hodgsonii)

“…()* of STR loci was 0.7767 and 0.8446 for the within and among-deme studies respectively. Our results are consistent with previous studies (Du et al, 2016;F. Zhang, Jiang, Xu, Zeng, & Li, 2013).…”

“…The Mantel test detected no IBD pattern with neither mtDNA CR nor STR loci. This finding suggests historically wide gene flow, which is consistent with results of previous studies (F. Zhang et al, 2013;H. Zhou et al, 2007).…”

Effects of Pleistocene climatic fluctuations on the phylogeography, demography and population structure of a high‐elevation snake species, Thermophis baileyi, on the Tibetan Plateau

“…Although the significance of the HTO for the evolution and biogeography of the Tibetan biota and those of adjacent regions is unquestioned, the influence of the geomorphological transformations, the corresponding glacial oscillations, and of the complex local topography on the distribution and diversification patterns of Tibetan species remains poorly understood (Yang et al, 2009;Qiu et al, 2011;Wang et al, 2011;Zhang et al, 2013). The lack of consensus on the chronology of the uplift (Spicer et al, 2003) and on the extent, timing and impact of Tibetan Plateau glaciations (Fu et al, 2013) as well as differences between taxa in evolutionary trajectories and responses to the same historical events (Yang et al, 2009)all contribute to this knowledge gap.…”