An endemic rat species complex is evidence of moderate environmental changes in the terrestrial biodiversity centre of China through the late Quaternary

Abstract

The underlying mechanisms that allow the Hengduan Mountains (HDM), the terrestrial biodiversity centre of China, to harbour high levels of species diversity remain poorly understood. Here, we sought to explore the biogeographic history of the endemic rat, Niviventer andersoni species complex (NASC), and to understand the long-term persistence of high species diversity in this region. In contrast to previous studies that have proposed regional refuges in eastern or southern of the HDM and emphasized the influence of climatic oscillations on local vertebrates, we found that HDM as a whole acted as refuge for the NASC and that the historical range shifts of NASC mainly occurred in the marginal regions. Demographic analyses revealed slight recent population decline in Yunnan and south-eastern Tibet, whereas of the populations in Sichuan and of the entire NASC were stable. This pattern differs greatly from classic paradigms of temperate or alpine and holarctic species. Interestingly, the mean elevation, area and climate of potential habitats of clade a (N. excelsior), an alpine inhabitant, showed larger variations than did those of clade b (N. andersoni), a middle-high altitude inhabitant. These species represent the evolutionary history of montane small mammals in regions that were less affected by the Quaternary climatic changes.

Dispersal route of the Asian house rat (Rattus tanezumi) on mainland China: insights from microsatellite and mitochondrial DNA

“…In these areas, the young uplifting plateau (Tibetan Plateau), the old eastern escarpment and the southeast slope (Hengduan Mountains) yield highly heterogeneous habitats not only to ‘living fossil’ species, such as the Laotian rock rat Laonastes aenigmamus [61] but also to some new speciated species, for example Apodemus ilex [62]. Besides the species level diversity, high intraspecific genetic diversity of some species in these areas was also frequently reported [63, 64] because these areas were refuges for different species during glacial periods. According to Musser and Carleton [65], R. tanezumi is indigenous to the north of the India subcontinent, South and Central China, and mainland Indochina in which Yunnan is the central area.…”

Gene Flow and Diversification in Himalopsyche martynovi Species Complex (Trichoptera: Rhyacophilidae) in the Hengduan Mountains

“…Considering the current distribution ranges of species of the H. martynovi -complex and our knowledge on range displacement during climate oscillations for organisms of the Hengduan Mts, we hypothesize that our results match with a general species-pump scenario. For example, it is often reported that species or populations have diverged allopatrically in the northern and southern Hengduan Mts, respectively [ 15 , 62 , 63 ]. This might have been the case for H. epikur (southern Hengduan Mts) and H. martynovi s.s. (northern Hengduan Mts), since these two species occur in drainage systems that were historically distinct [ 64 ].…”

“…In the Hengduan Mts, climate changes and orogenic movements profoundly changed the relative frequency and the distribution of available habitats, affecting species movement and distributions and ultimately speciation and patterns of diversity [ 13 ]. Species complexes are common in the Hengduan Mts (e.g., plant [ 14 ], mammal [ 15 ], fungus [ 16 ], caddisflies [ 17 ]) and represent good models for studying evolutionary processes and mechanisms of speciation in the context of the mountain-geobiodiversity hypothesis.…”

Dynamics behind disjunct distribution, hotspot-edge refugia, and discordant RADseq/mtDNA variability: insights from the Emei mustache toad

“…This possibility and the recurrent range fragmentation and contraction caused by Quaternary climatic changes could lead to a largely disjunct distribution. Such a model provides a hypothesis for explaining scattered ranges and can be considered in future studies of the evolutionary histories of frogs and many other organisms isolated in the mountains surrounding the Sichuan Basin [38,39,48,63,64,66,67]. A substantially different modeled LIG distribution compared with those during the present interglacial period is not unique to the Emei mustache toad.…”