Evolutionary history and underlying adaptation of alpine plants on the Qinghai–Tibet Plateau

Abstract

As the highest and largest plateau in the world, the Qinghai-Tibet Plateau, with its numerous endemic species, is one of the important alpine biodiversity hotspots. Only recently have the evolutionary histories and underlying adaptations of these alpine plants become clear, through research mostly based on testable experiments and analyses. In this issue, we collected a total of 13 papers related to such aims. In addition, we selected a few published papers to highlight the major findings in the recent past. We also outlined the outlook and direction of future research.

Evolutionary history of Orinus thoroldii (Poaceae), endemic to the western Qinghai-Tibetan Plateau in China

“…In such situations, independent genetic lineages appeared in different plateau regions due to isolations among developed ice sheets. However, although earlier investigations focused on species that populate the eastern, central and northern portions of the QTP, few involved plants were found in the western part of that plateau (Qiu et al, 2011;Liu et al, 2012Liu et al, , 2014.…”

“…Furthermore, because the QTP was most sensitive and vulnerable to the Pleistocene global climate (Zhang, 1983;Raymo and Ruddiman, 1992;Zhan, 2005), growth, reproduction, and survival of existing species have depended greatly upon exposure to suitable temperatures (Zheng, 1996;Ni, 2000;Thompson et al, 2000). Therefore, it is a very favorable area to study the evolutionary histories of plants in response to previous climate change (Bawa et al, 2010;Liu et al, 2012Liu et al, , 2014.…”

Gene Flow Results in High Genetic Similarity between Sibiraea (Rosaceae) Species in the Qinghai-Tibetan Plateau

“…Mountains in the QTP with the potential to act as barriers to movement can result in genetic structures ranging from panmixia (Lessios et al, 2003) to complete separation (Baums et al, 2012). Therefore, species on the QTP likely experienced an evolution history different from other areas of the world (Liu et al, 2014; Wen et al, 2014). …”

Molecular identification and allopatric divergence of the white pine species in China based on the cytoplasmic DNA variation

“…We did not calibrate these divergences due to the lack of the reliable fossils and mutation rate. However, numerous studies of species diversification for other genera suggested the rapid uplifts of the Qinghai-Tibet Plateau since the Miocene and the subsequent climate change should have caused habitat fragmentation across China, which had probably triggered allopatric speciation in numerous genera occurred there (Liu et al, 2002(Liu et al, , 2006(Liu et al, , 2012b(Liu et al, , 2014bXu et al, 2010;Liu et al, 2013). In addition, all detected mitotypes or chlorotypes should have produced before the last glaciation maximum (LGM, around 18e21 Ka BP) of the Quaternary.…”

“…However, discrimination power for species identification based on sequence variations will change dependent on the geographic isolations and possible speciation ages. In addition to test this hypothesis, our range-wide sampling and two large population genetic datasets based on cytoplasmic DNA variation undoubtedly will aid to understand the interspecific relationship of these species and their response to the historical climate changes (Liu et al, 2012b(Liu et al, , 2014bHao et al, 2015).…”