Phylogeography of the Tibetan hamster Cricetulus kamensis in response to uplift and environmental change in the Qinghai–Tibet Plateau

Abstract

Aim The evolutionary process of an organism provides valuable data toward an understanding of the Earth evolution history. To investigate the relationship between the uplift of the Qinghai–Tibet Plateau (QTP) and mammalian evolution since the late Cenozoic, the geographic distribution of genetic variations in the Tibetan hamster Cricetulus kamensis was investigated using phylogeographical methods. In particular, population divergence, demographic history, genetic variation, and the prediction of species distribution area were investigated. Location The Qinghai–Tibet Plateau. Methods A total of 53 specimens, representing 13 geographic populations, were collected from the QTP. The phylogeographical pattern and demographic history of C. kamensis were analyzed, and the probable factors in the QTP uplift and the Quaternary glacial periods were inferred from one nuclear and four mitochondrial genes. Furthermore, the species distribution model (SDM) was used to predict changes in potentially suitable habitats since the last Interglacial. Results Phylogenetic analysis demonstrated that two major genetic differentiations of the C. kamensis population occurred during the Early Pleistocene that were influenced by the Qing‐Zang tectonic movement from the Middle Pliocene to the Early Pleistocene. Genetic distance between two major clades indicated low genetic divergence. Demographic history analysis showed that the C. kamensis population was affected by the Quaternary glacial period. SDM analysis indicated that C. kamensis was endemic to the QTP and the suitable habitat was affected by climate change, especially during the Last Glacial Maximum (LGM). Main conclusion Our results indicated that the QTP uplift led to the population divergence of C. kamensis, and vicariance well accounted for the geographic distribution of genetic variation in C. kamensis as a result of genetic divergence and lack of gene flow. The genetic distance shows that C. alticola may be a subspecies of C. kamensis. Demographic history analysis suggests that the QTP was affected by the last glacial period. SDM analysis supports that almost the entire QTP is covered by a huge ice sheet during the LGM.

Karyotypic and molecular evidence supports the endemic Tibetan hamsters as a separate divergent lineage of Cricetinae

“…All these sequences belong to clade A as determined in ref. 3 , which we believe to correspond to true U. kamensis occurring in eastern Tibet and Nanshan.…”

“…8 ), as Cricetulus members. Recent nuclear and mitochondrial data are consistent with the view that U. kamensis and U. alticola are distinct, albeit closely related species 2 ; however, this treatment is opposed by Ding and Liao 3 , who advocate the monotypy of the genus.…”

“…The Kam hamster Urocricetus kamensis (Satunin, 1903 [imprint 1902]) is a member of the lineage commonly known as Tibetan hamsters, which is one of the few rodent taxa endemic to the Qinghai-Tibet plateau where it is found at altitudes up to 5200 m above the sea level 1 . Over the past century, the classification of Tibetan hamsters based on morphological characteristics has been controversial 2 , 3 . Superficial similarity with another group of small hamsters affiliated with the genus Cricetulus Milne-Edwards, 1867 (e.g.…”

“…1 , 7 ; for more details see ref. 3 ). Nonetheless, in most checklists, only U. kamensis and U. alticola (Thomas, 1917) have been regarded as valid species (e.g., ref.…”

The East Asian Winter Monsoon Acts as a Major Selective Factor in the Intraspecific Differentiation of Drought-Tolerant Nitraria tangutorum in Northwest China

“…It is widely believed that the range of a large proportion of alpine species contracted under glacial oscillations, and that this phenomenon accelerated the process of genetic divergence. This premise has been documented in many species of plants [ 16 , 19 , 39 , 48 , 49 ] and animals [ 50 , 51 , 52 ]. Two bioclimate factors, ‘precipitation’ and ‘temperature’, were greatly reduced during the LGM [ 53 ], and have been identified as the major factors determining suitable distribution ranges for N. tangutorum ( Supplementary Table S4 ).…”