scholarly journals Demographic history and genomic response to environmental changes in a rapid radiation of wild rats

Author(s):  
Deyan Ge ◽  
Anderson Feijó ◽  
Zhixin Wen ◽  
Alexei V Abramov ◽  
Liang Lu ◽  
...  

Abstract For organisms to survive and prosper in a harsh environment, particularly under rapid climate change, poses tremendous challenges. Recent studies have highlighted the continued loss of megafauna in terrestrial ecosystems and the subsequent surge of small mammals, such as rodents, bats, lagomorphs, and insectivores. However, the ecological partitioning of these animals will likely lead to large variation in their responses to environmental change. In the present study, we investigated the evolutionary history and genetic adaptations of white-bellied rats (Niviventer Marshall, 1976), which are widespread in the natural terrestrial ecosystems in Asia but also known as important zoonotic pathogen vectors and transmitters. The southeastern Qinghai-Tibet Plateau (QHTP) was inferred as the origin center of this genus, with parallel diversification in temperate and tropical niches. Demographic history analyses from mitochondrial and nuclear sequences of Niviventer demonstrated population size increases and range expansion for species in Southeast Asia, and habitat generalists elsewhere. Unexpectedly, population increases were seen in N. eha, which inhabits the highest elevation among Niviventer species. Genome scans of nuclear exons revealed that among the congeneric species, N. eha has the largest number of positively selected genes. Protein functions of these genes are mainly related to olfaction, taste and tumor suppression. Extensive genetic modification presents a major strategy in response to global changes in these alpine species.

2010 ◽  
Vol 60 (4) ◽  
pp. 449-465
Author(s):  
Wen Longying ◽  
Zhang Lixun ◽  
An Bei ◽  
Luo Huaxing ◽  
Liu Naifa ◽  
...  

AbstractWe have used phylogeographic methods to investigate the genetic structure and population history of the endangered Himalayan snowcock (Tetraogallus himalayensis) in northwestern China. The mitochondrial cytochrome b gene was sequenced of 102 individuals sampled throughout the distribution range. In total, we found 26 different haplotypes defined by 28 polymorphic sites. Phylogenetic analyses indicated that the samples were divided into two major haplogroups corresponding to one western and one eastern clade. The divergence time between these major clades was estimated to be approximately one million years. An analysis of molecular variance showed that 40% of the total genetic variability was found within local populations, 12% among populations within regional groups and 48% among groups. An analysis of the demographic history of the populations suggested that major expansions have occurred in the Himalayan snowcock populations and these correlate mainly with the first and the second largest glaciations during the Pleistocene. In addition, the data indicate that there was a population expansion of the Tianshan population during the uplift of the Qinghai-Tibet Plateau, approximately 2 million years ago.


2020 ◽  
Author(s):  
Wenjie Wan ◽  
Geoffrey Michael Gadd ◽  
Yuyi Yang ◽  
Wenke Yuan ◽  
Jidong Gu ◽  
...  

Abstract Background: Disentangling the biogeographic patterns of rare and abundant microbial sub-communities is essential in order to understand the generation and maintenance of microbial diversity with respect to the functions they provide. However, little is known about ecological assembly processes and environmental adaptation of rare and abundant microbial sub-communities across large spatial-scale wetlands. Using Illumina sequencing, we investigated the taxonomic and phylogenetic β-diversity of rare and abundant bacterial and fungal sub-communities in Qinghai-Tibet Plateau wetland soils. Additionally, we determined environmental breadths and phylogenetic signals of ecological preferences of rare and abundant microbial sub-communities, and investigated community assembly processes of microbial taxa. Results: We found that both taxonomic and phylogenetic similarities of rare and abundant microbial sub-communities attenuated with geographical distance. Based on threshold indicator taxa analysis and Blomberg’s K statistic, abundant microbial taxa exhibited broader environmental thresholds and stronger phylogenetic signals for ecological traits than rare microbial taxa. The strong correlations between community compositional dissimilarity and phylogenetic distance of rare microbial sub-communities also revealed that rare taxa may be more sensitive to environmental changes. In addition, the rare microbial sub-communities exhibited closer phylogenetic clustering compared with abundant microbial sub-communities. The null model analysis revealed that dispersal limitation belonging to stochastic process dominated ecological assembly of abundant bacterial sub-community, and rare and abundant fungal sub-communities; variable selection belonging to deterministic process governed community assembly of rare bacterial taxa. Neutral model analysis and variation partitioning analysis further confirmed that abundant microbial sub-communities were less environmentally constrained. Soil ammonia nitrogen was the crucial factor in mediating the balance between stochasticity and determinism of both rare and abundant microbial sub-communities, as reflected by distinct differences in stochastic process with higher ammonia nitrogen content.Conclusions: Abundant microbial sub-communities may have better environmental adaptation potential and are less dispersed by environmental changes compared with rare microbial sub-communities. Our findings extend knowledge of the adaptation of rare and abundant microbial taxa to ongoing environmental change and could facilitate prediction of biodiversity loss caused by global climate change and increasing human activity in wetlands of the Qinghai-Tibet Plateau.


2021 ◽  
Author(s):  
Ailin Zhang ◽  
Shixin Wu ◽  
Fanjiang Zeng ◽  
Yong Jiang ◽  
Ruzhen Wang ◽  
...  

Abstract Purpose: In grassland ecosystems, plant functional group (PFG) is an important bridge connecting individual plant to community system. Grassland ecosystem is the main ecosystem type on the Qinghai-Tibet Plateau, so the change of community structure of grassland vegetation.Methods: The Altun Mountains in the northern part of the Qinghai-Tibet Plateau were used as the study area to investigate the PFGs of a high-altitude (> 3700m) grassland in desert areas and their response to temperature and moisture.Results: The main functional groups were forbs and grasses, and the importance values (IV) accounted for more than 50%. Plant species diversity of the community was influenced by the functional groups of legumes IV, and the increase of legumes would promote the increase of plant community diversity. The C, N, P of plant communities were mainly influenced by forbs and grasses, and the relationship between forbs and C, N, P was opposite to that of grasses. There was a positive correlation between forbs and soil TP; a negative correlation between grasses and soil TP; a positive correlation between legumes with soil SOC and TN; and a positive correlation between sedge and soil SOC. However, under the influence of different hydrothermal conditions, forbs and grasses as dominant functional groups had stronger correlation with community and soil nutrients. Conclusions: This indicated that the PFGs with the largest proportion in the community had the greatest influence on the community. This provides a basis for the study of alpine grassland community development and ecosystem function under alpine grassland.


2021 ◽  
Vol 13 (18) ◽  
pp. 10402
Author(s):  
Shao Sun ◽  
Qiang Zhang ◽  
Yuanxin Xu ◽  
Ruyue Yuan

Recent decades have witnessed accelerated climate changes across the Qinghai-Tibet Plateau (QTP) and elevated socioeconomic exposure to meteorological hazards. The QTP is called the “the third pole”, exerting remarkable impact on environmental changes in its surrounding regions. While few reports are available for addressing multi-hazard risks over the QTP, we develop an integrated indicator system involving multiple meteorological hazards, i.e., droughts, rainstorms, snowstorms and hailstorms, investigating the spatiotemporal patterns of major hazards over the QTP. The hazard zones of droughts and rainstorms are identified in the southern Gangdise Mountains, the South Tibet Valley, the eastern Nyenchen-Tanglha Mountains, the Hengduan Mountains and West Sichuan Basin. Snowstorm hazard zones distribute in the Himalayas, the Bayan Har Mountains and the central Nyenchen-Tanglha Mountains, while hailstorm hazard zones cluster in central part of the QTP. Since the 21st century, intensified rainstorms are detectable in the densely populated cities of Xining and Lhasa and their adjacent areas, while amplified droughts are observed in grain production areas of the South Tibet Valley and the Hengduan Mountains. Snowstorm hazards show large interannual variations and an increase in pastoral areas, although the overall trend is declining slightly. The frequency of hailstorms gradually decreases in human settlements due to thermal and landscape effects. Mapping meteorological hazards regionalization could help to understand climate risks in the QTP, and provide scientific reference for human adaptation to climate changes in highly sensitive areas.


2019 ◽  
Vol 20 (6) ◽  
pp. 1289-1301 ◽  
Author(s):  
Jingjing Xu ◽  
Xinya Song ◽  
Markus Ruhsam ◽  
Tingxuan Liu ◽  
Jialiang Li ◽  
...  

2021 ◽  
Author(s):  
Xu Zhang ◽  
Jacob B. Landis ◽  
Yanxia Sun ◽  
Huajie Zhang ◽  
Tao Feng ◽  
...  

AbstractThe Qinghai-Tibet Plateau (QTP) encompasses areas with a remarkably high degree of biodiversity, harboring exceptional species-rich radiations. How these radiations formed by interacting with geology, climate and ecology remains seldom examined.We investigate the roles of abiotic (environmental) and biotic (species-intrinsic) factors in driving radiating diversification of Saussurea (Asteraceae) by deploying a number of time-dependent, paleoenvironment-dependent and trait-dependent models, as well as ecological distribution data.We show that three main clades of Saussurea begin to diversify in the Miocene almost simultaneously, with increasing diversification rates toward the present and negative dependence to paleotemperature. Acceleration in diversification rates are correlated with adaptive traits, as well climate lability, niche breadth and species range.We conclude that fluctuation of paleoclimate along with complex QTP environments provided opportunities for increased diversification rates of Saussurea with diverse adaptive traits, highlighting the importance of combinations of clade-specific traits and ecological niches in driving rapid radiation.


2021 ◽  
Author(s):  
guo xiali ◽  
Valentina Buttò ◽  
Yann Surget-Groba ◽  
Jian-Guo Huang ◽  
Sylvain Delagrange ◽  
...  

Abstract Global changes affect the growing conditions of terrestrial ecosystems, mismatching the phenological adaptation of plants to local climates at mid and high latitudes. Their long lifespan and slow reproductive cycles prevent trees from tracking the quick shift in their usual climatic conditions, thus endangering the survival of local populations. In this study, we explored the phenological plasticity and adaptive potential of bud burst in sugar maple (Acer saccharum Marsh.) seedlings from 30 Canadian origins with contrasting climates planted in two common gardens near and at the northern boundary of the species range. Bud development and leafing occurred in April-May, with complete bud burst lasting between 21 and 29 days. On average, bud swelling differed by 12 days between common gardens. However, this difference decreased to 4 days for complete leafing. Both factors site and seed origin affected bud burst, which represented the phenological plasticity and adaptation of sugar maple, respectively. Overall, the former (7.4–88.3%) contributed more than the latter (9.2–25.5%) to the variance in bud burst, despite the wide climatic range among the provenance origins compared with that at the two common gardens. Adaptation to local conditions provide the genetic tools for the survival of species across wide climatic ranges. Plasticity enables physiological responses of individuals to quick environmental changes. Our study demonstrated the major role of plasticity in bud phenology, and revealed the importance of investing resources in mechanisms dealing with the climatic challenges due to inter-annual variations in weather events.


2014 ◽  
Vol 60 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Fumin Lei ◽  
Yanhua Qu ◽  
Gang Song

Abstract The Qinghai-Tibet Plateau (QTP) is well known for being of great importance in the evolution of montane species due to its unique geological history and landform configuration, climate complexity, and diversified habitats. The effect of environmental changes since the Quaternary on species diversification, population genetic structure, and demography under environmental change can be studied using phylogenetic and phylogeographical approaches. Birds are the most well-studied group of all terrestrial vertebrates with regard to their response to climatic changes over time. Herein, we briefly review the species diversification of birds in response to the uplift of the QTP, focusing on summarizing the different phylogeographical patterns of birds on the Plateau, its southeastern margin, and the Eastern Himalayas and the reasons underlying these patterns. Speciation was found to be closely related to the uplift of the QTP, with different patterns of intraspecific processes: (1) no divergence within a single refuge was identified in a restricted semi-continuous area of the eastern margin of the Plateau; (2) two divergent lineages with separated refugia were located at the south-eastern and north-eastern margins of the plateau; and (3) multiple divergent lineages within subregions were found in the Eastern Himalayas. Glacial movements and induced climate change are considered to be key factors in shaping these different patterns. The species distributed mainly in the heavily ice-covered platform regions of the Plateau experienced population expansion following the retreat of the extensive glaciations, whereas the species distributed on the ice-free edges of the plateau maintained their population size at a stable level. Demographic stresses on the edge species might have been mitigated by the milder climate in comparison to their platform-distributed counterparts. Various behavioral and ecological characteristics, including dispersal capacity, habitat preference, and elevation specificity, along with evolutionary history might have helped to shape these different phylogeographical patterns.


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