scholarly journals Phylogeography of the desert scorpion Mesobuthus mongolicus illuminates a route out of Central Asia and Junggar Basin as a corridor for faunal exchange between Central and East Asia

2021 ◽  
Author(s):  
Cheng-Min Shi ◽  
Xue-Shu Zhang ◽  
Lin Liu ◽  
De-Xing Zhang
Keyword(s):  
East Asia ◽  
Central Asia ◽  
Climate Changes ◽  
Ecological Niche Modeling ◽  
Mitochondrial Gene ◽  
Biological Evolution ◽  
Population Expansion ◽  
Junggar Basin ◽  
Molecular Dating ◽  
Ancestral Population

A comprehensive understanding of the ecological, evolutionary and genetic consequences of climate changes requires integration of information from different geographic regions and ecosystems. However, a clear knowledge gap exists in arid biota of Asian drylands, where climate change and biological evolution demonstrate high regional specificity. We report here our phylogeographic study on the desert scorpion Mesobuthus mongolicus, attempting to narrow the gap. Range wide samples for one mitochondrial gene and three nuclear loci were subjected to phylogenetic inferences, molecular dating, Bayesian phylogeographic and demographic reconstructions, and population genetic analyses. Ecological niche modeling was employed to generate models of potential distribution range at present and during the last glacial maximum (LGM). Our results revealed that M. mongolicus represents a single coherent lineage that diverged with its most closely related lineage from Central Asia about 1.36 Ma and underwent radiation ever since. Bayesian phylogeographic reconstruction suggested the ancestral population of M. mongolicus dispersed gradually eastward through the Junngar Basin to the Gobi region during the late Pleistocene, strengthening the view that the Junggar Basin has constituted an important corridor for faunal exchange between Central Asian and East Asia. We found that the desert scorpion underwent demographic expansion while experiencing range contraction during the LGM. Development of sandy deserts in northwest China incurred by Eurasian aridification might have opened up substantial empty niches that sustained population expansion during the LGM. Our results suggested that organisms' ecological adaptations have acted as an important determinant for their phylogeographic and demographic responses to past climate changes.

scholarly journals Intraspecific mitochondrial gene variation can be as low as that of nuclear rRNA

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 339 ◽  
Author(s):  
Tshifhiwa G. Matumba ◽  
Jody Oliver ◽  
Nigel P. Barker ◽  
Christopher D. McQuaid ◽  
Peter R. Teske
Keyword(s):  
Dna Barcoding ◽  
Dna Sequences ◽  
Sequence Data ◽  
Mitochondrial Gene ◽  
Population Expansion ◽  
Species Level ◽  
Molecular Dating ◽  
Coi Gene ◽  
28S Rrna ◽  
Mtdna Sequence

Background: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality. Methods: DNA sequences were generated for the mtDNA COI gene and the nuclear 28S rRNA of two closely related rocky shore snails, and species-level variation was compared. Nuclear rRNA is not usually used to study intraspecific variation in species that are not spatially structured, presumably because this marker is assumed to evolve so slowly that it is more suitable for phylogenetics.  Results: Even though high inter-specific divergence reflected the faster evolutionary rate of COI, intraspecific genetic variation was similar for both markers. As a result, estimates of population expansion times based on mismatch distributions differed between the two markers by millions of years. Conclusions: Assuming that 28S evolution is more clock-like, these findings can be explained by variation-reducing purifying selection in mtDNA at the species level, and an elevated divergence rate caused by diversifying selection between the two species. Although these two selective forces together make mtDNA suitable as a marker for species identifications by means of DNA barcoding because they create a ‘barcoding gap’, estimates of demographic change based on this marker can be expected to be highly unreliable. Our study contributes to the growing evidence that the utility of mtDNA sequence data beyond DNA barcoding is limited.

scholarly journals Purifying selection can reduce intraspecific mitochondrial gene variation to that of nuclear rRNA

2020 ◽  
Author(s):  
Tshifhiwa G. Matumba ◽  
Jody Oliver ◽  
Nigel P. Barker ◽  
Christopher D. McQuaid ◽  
Peter R. Teske
Keyword(s):  
Mitochondrial Dna ◽  
Dna Barcoding ◽  
Dna Sequences ◽  
Mitochondrial Gene ◽  
Population Expansion ◽  
Purifying Selection ◽  
Species Level ◽  
Molecular Dating ◽  
Coi Gene ◽  
28S Rrna

AbstractMitochondrial DNA (mtDNA) has long been used to date the divergence between species, and to explore the time when species’ effective population sizes changed. The idea that mitochondrial DNA is useful for molecular dating rests on the premise that its evolution is neutral. This premise was questionable to begin with, and even though it has long been challenged, the evidence against clock-like evolution of mtDNA is usually ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality. DNA sequences were generated for the mtDNA COI gene and the nuclear 28S rRNA of two closely related and widely distributed rocky shore snails whose geographical ranges are defined by different thermal preferences. To our knowledge, this is the first study to use nuclear rRNA sequence for studying species-level genealogies instead of phylogenetics, presumably because this marker is considered to be uninformative at this taxonomic level. Even though the COI gene evolves at least an order of magnitude faster, which was reflected in high inter-specific divergence, intraspecific genetic variation was similar for both markers. As a result, estimates of population expansion times based on mismatch distributions were completely different for the two markers. Assuming that 28S evolves effectively clock-like, these findings likely illustrate variation-reducing purifying selection in mtDNA at the species level, and an elevated divergence rate caused by divergent selection between the two species. Although these two selective forces together make mtDNA suitable as a DNA barcoding marker because they create a ‘barcoding gap’, estimates of demographic change can be expected to be highly unreliable. Our study contributes to the growing evidence that the utility of mtDNA beyond DNA barcoding is limited.

scholarly journals Molecular Biogeography of Tribe Thermopsideae (Leguminosae): A Madrean-Tethyan Disjunction Pattern with an African Origin of Core Genistoides

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Ming-Li Zhang ◽  
Jian-Feng Huang ◽  
Stewart C. Sanderson ◽  
Ping Yan ◽  
Yu-Hu Wu ◽  
...  
Keyword(s):  
North America ◽  
East Asia ◽  
Central Asia ◽  
Sequence Data ◽  
Distribution Patterns ◽  
Molecular Dating ◽  
Biogeographical Distribution ◽  
Central Asian ◽  
Xizang Plateau ◽  
Molecular Biogeography

Thermopsideae has 45 species and exhibits a series of interesting biogeographical distribution patterns, such as Madrean-Tethyan disjunction and East Asia-North America disjunction, with a center of endemism in the Qinghai-Xizang Plateau (QTP) and Central Asia. Phylogenetic analysis in this paper employed maximum likelihood using ITS,rps16,psbA-trnH, andtrnL-F sequence data; biogeographical approaches included BEAST molecular dating and Bayesian dispersal and vicariance analysis (S-DIVA). The results indicate that the core genistoides most likely originated in Africa during the Eocene to Oligocene, ca. 55-30 Ma, and dispersed eastward to Central Asia at ca. 33.47 Ma. The origin of Thermopsideae is inferred as Central Asian and dated to ca. 28.81 Ma.Ammopiptanthusis revealed to be a relic. Birth of the ancestor of Thermopsideae coincided with shrinkage of the Paratethys Sea at ca. 30 Ma in the Oligocene. The Himalayan motion of QTP uplift of ca. 20 Ma most likely drove the diversification between Central Asia and North America. Divergences in East Asia, Central Asia, the Mediterranean, and so forth, within Eurasia, except forAmmopiptanthus, are shown to be dispersals from the QTP. The onset of adaptive radiation at the center of the tribe, with diversification of most species inThermopsisandPiptanthusat ca. 4-0.85 Ma in Tibet and adjacent regions, seems to have resulted from intense northern QTP uplift during the latter Miocene to Pleistocene.

scholarly journals Intraspecific mitochondrial gene variation can be as low as that of nuclear rRNA

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 339 ◽  
Author(s):  
Tshifhiwa G. Matumba ◽  
Jody Oliver ◽  
Nigel P. Barker ◽  
Christopher D. McQuaid ◽  
Peter R. Teske
Keyword(s):  
Dna Barcoding ◽  
Dna Sequences ◽  
Sequence Data ◽  
Mitochondrial Gene ◽  
Population Expansion ◽  
Species Level ◽  
Molecular Dating ◽  
Coi Gene ◽  
28S Rrna ◽  
Mtdna Sequence

Background: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality. Methods: DNA sequences were generated for the mtDNA COI gene and the nuclear 28S rRNA of two closely related rocky shore snails, and species-level variation was compared. To our knowledge, this is the first study to use nuclear rRNA at this taxonomic level, presumably because this marker is assumed to evolve so slowly that it is only suitable for phylogenetics.   Results: Even though high inter-specific divergence reflected the faster evolutionary rate of COI, intraspecific genetic variation was similar for both markers. As a result, estimates of population expansion times based on mismatch distributions differed between the two markers by millions of years. Conclusions: Assuming that 28S evolves effectively clock-like, these findings can be explained by variation-reducing purifying selection in mtDNA at the species level, and an elevated divergence rate caused by diversifying selection between the two species. Although these two selective forces together make mtDNA suitable as a marker for species identifications by means of DNA barcoding because they create a ‘barcoding gap’, estimates of demographic change based on this marker can be expected to be highly unreliable. Our study contributes to the growing evidence that the utility of mtDNA sequence data beyond DNA barcoding is limited.

English in Asia, Asian Englishes, and the issue of proficiency

English Today ◽  
2008 ◽  
Vol 24 (2) ◽  
pp. 3-12 ◽  
Author(s):  
Kingsley Bolton
Keyword(s):  
Middle East ◽  
Southeast Asia ◽  
East Asia ◽  
South Asia ◽  
Central Asia ◽  
English Learning ◽  
Outer Circle ◽  
Asian Region ◽  
The World ◽  
Basic Issue

ABSTRACTThe contemporary visibility and importance of English throughout the Asian region coupled with the emergence and development of distinct varieties of Asian Englishes have played an important part in the global story of English in recent years. Across Asia, the numbers of people having at least a functional command of the language have grown exponentially over the last four decades, and current changes in the sociolinguistic realities of the region are often so rapid that it is difficult for academic commentators to keep pace. One basic issue in the telling of this story is the question of what it is we mean by the term ‘Asia’, itself a word of contested etymology, whose geographical reference has ranged in application from the Middle East to Central Asia, and from the Indian sub-continent to Japan and Korea. In this article, my discussion will focus on the countries of South Asia, Southeast Asia, and East Asia, as it is in these regions that we find not only the greatest concentration of ‘outer-circle’ English-using societies but also a number of the most populous English-learning and English-knowing nations in the world.

Integration in post-Soviet Central Asia

2020 ◽  
Author(s):  
Ivan Zuenko
Keyword(s):  
International Relations ◽  
East Asia ◽  
Central Asia ◽  
Political Ties ◽  
Active Search ◽  
Eurasian Economic Union ◽  
One Belt One Road ◽  
Economic Union ◽  
Soviet Central Asia

The 2010s became the time of active search for new forms of integration in the wide Eurasian space between Europe and East Asia. The most well-known is China’s One Belt One Road (OBOR) initiative and the Eurasian Economic Union (EAEU). A 7000-kilometre border between China and the EAEU was formed in 2015, which became a crucial factor in the cooperation of China and Post-Soviet Central Asia. Many regard the EAEU as just a Moscow geopolitical project and underestimated its real impacts on economic and political ties in Eurasia, particularly in post-Soviet Central Asia. This chapter examines the EAEU as a factor of international relations in the global discussion about the OBOR initiative.

The PMIP3 Simulated Climate Changes over Arid Central Asia during the Mid‐Holocene and Last Glacial Maximum

2020 ◽  
Vol 94 (3) ◽  
pp. 725-742
Author(s):  
Hongna XU ◽  
Tao WANG ◽  
Huijun WANG ◽  
Jiapeng MIAO ◽  
Jianhui CHEN ◽  
...  
Keyword(s):  
Central Asia ◽  
Last Glacial Maximum ◽  
Climate Changes ◽  
Glacial Maximum ◽  
Arid Central Asia ◽  
Last Glacial ◽  
Simulated Climate

scholarly journals Evidence of ancient DNA reveals the first European lineage in Iron Age Central China

2007 ◽  
Vol 274 (1618) ◽  
pp. 1597-1602 ◽  
Author(s):  
C.Z Xie ◽  
C.X Li ◽  
Y.Q Cui ◽  
Q.C Zhang ◽  
Y.Q Fu ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
East Asia ◽  
Central Asia ◽  
Iron Age ◽  
Ancient Dna ◽  
Human Remains ◽  
Central China ◽  
Population Movement ◽  
Ancient China

Various studies on ancient DNA have attempted to reconstruct population movement in Asia, with much interest focused on determining the arrival of European lineages in ancient East Asia. Here, we discuss our analysis of the mitochondrial DNA of human remains excavated from the Yu Hong tomb in Taiyuan, China, dated 1400 years ago. The burial style of this tomb is characteristic of Central Asia at that time. Our analysis shows that Yu Hong belonged to the haplogroup U5, one of the oldest western Eurasian-specific haplogroups, while his wife can be classified as haplogroup G, the type prevalent in East Asia. Our findings show that this man with European lineage arrived in Taiyuan approximately 1400 years ago, and most probably married a local woman. Haplogroup U5 was the first west Eurasian-specific lineage to be found in the central part of ancient China, and Taiyuan may be the easternmost location of the discovered remains of European lineage in ancient China.

Sign in / Sign up

Export Citation Format

Share Document