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Sequestration of CO2 in the unmineable coal seams is not only one of the most ideal options for reducing greenhouse gas effects, but also the only way for the coal industry to reduce CO2 emissions and achieve low carbonization sustainable development. However, the key unresolved issues regarding the CO2 geo-sequestration in coal seams is: “how long does CO2 injected into a coal seam remain in the seam?”. In this regard, on the basis of clarifying the hysteresis law of CO2 desorption in coals, this paper reveals the mechanism of supercritical CO2 desorption hysteresis, establishes a quantitative model for the geological storage of CO2, and explores the use of desorption hysteresis to achieve a long-term safe storage of CO2 in coal seams. The study results shows that the degree of desorption hysteresis of supercritical CO2 in coal is greater than that of subcritical CO2, and a stable hysteresis characteristic similar to a “parallel line” in the supercritical phase is formed between the adsorption and desorption isotherm. The fundamental reason for the desorption hysteresis is that the micro and nano sized pores in coal form curved surfaces due to their hydrophilicity, which generate strong capillary pressure following the Laplace’s equation, absorb liquid water, truncate and fix the supercritical CO2 fluid, and ultimately form CO2 residual trapping. For example, the cylindrical inorganic pores with a diameter of 40–10 nm in coal can generate a capillary pressure of 7.30–29.12 MPa, which is sufficient to block supercritical CO2. Taking the desorption isotherm of Jiulishan coal as an example, using the quantitative model for the geological storage of CO2 established in this study, it has been estimated that the total trapping capacity of the No.21 coal seam at depths of 900–1 500 m is stable at 35–37 m3/t. Among them, the adsorption trapping capacity accounts for about 80%, residual trapping capacity accounts for about 15%, and structural trapping capacity only accounts for 5%. Desorption hysteresis suggests that some measures should be taken to increase the proportion of CO2 residual trapping in coal seams as much as possible, the reason is that the residual CO2 sealed by capillary blockage is safer and has no risk of leakage compared to the free and adsorbed CO2 sealed by surrounding rock. The physical parameters such as ash content, moisture content, pore size, and morphology of coal seams are the main factors affecting the residual trapping efficiency.

Abstract Background The underrepresentation of human genomic resources from Southern Chinese populations limited their health equality in the precision medicine era and complete understanding of their genetic formation, admixture, and adaptive features. Besides, linguistical and genetic evidence supported the controversial hypothesis of their origin processes. One hotspot case was from the Chinese Guangxi Pinghua Han people (GPH), whose language was significantly similar to Southern Chinese dialects but whose uniparental gene pool was phylogenetically associated with the indigenous Tai-Kadai (TK) people. Here, we analyzed genome-wide SNP data in 619 people from four language families and 56 geographically different populations, in which 261 people from 21 geographically distinct populations were first reported here. Results We identified significant population stratification among ethnolinguistically diverse Guangxi populations, suggesting their differentiated genetic origin and admixture processes. GPH shared more alleles related to Zhuang than Southern Han Chinese but received more northern ancestry relative to Zhuang. Admixture models and estimates of genetic distances showed that GPH had a close genetic relationship with geographically close TK compared to Northern Han Chinese, supporting their admixture origin hypothesis. Further admixture time and demographic history reconstruction supported GPH was formed via admixture between Northern Han Chinese and Southern TK people. We identified robust signatures associated with lipid metabolisms, such as fatty acid desaturases (FADS) and medically relevant loci associated with Mendelian disorder (GJB2) and complex diseases. We also explored the shared and unique selection signatures of ethnically different but linguistically related Guangxi lineages and found some shared signals related to immune and malaria resistance. Conclusions Our genetic analysis illuminated the language-related fine-scale genetic structure and provided robust genetic evidence to support the admixture hypothesis that can explain the pattern of observed genetic diversity and formation of GPH. This work presented one comprehensive analysis focused on the population history and demographical adaptative process, which provided genetic evidence for personal health management and disease risk prediction models from Guangxi people. Further large-scale whole-genome sequencing projects would provide the entire landscape of southern Chinese genomic diversity and their contributions to human health and disease traits.

Abstract Background The underrepresentation of Hmong-Mien (HM) people in Asian genomic studies has hindered our comprehensive understanding of the full landscape of their evolutionary history and complex trait architecture. South China is a multi-ethnic region and indigenously settled by ethnolinguistically diverse HM, Austroasiatic (AA), Tai-Kadai (TK), Austronesian (AN), and Sino-Tibetan (ST) people, which is regarded as East Asia’s initial cradle of biodiversity. However, previous fragmented genetic studies have only presented a fraction of the landscape of genetic diversity in this region, especially the lack of haplotype-based genomic resources. The deep characterization of demographic history and natural-selection-relevant genetic architecture of HM people was necessary. Results We reported one HM-specific genomic resource and comprehensively explored the fine-scale genetic structure and adaptative features inferred from the genome-wide SNP data of 440 HM individuals from 33 ethnolinguistic populations, including previously unreported She. We identified solid genetic differentiation between HM people and Han Chinese at 7.64‒15.86 years ago (kya) and split events between southern Chinese inland (Miao/Yao) and coastal (She) HM people in the middle Bronze Age period and the latter obtained more gene flow from Ancient Northern East Asians. Multiple admixture models further confirmed that extensive gene flow from surrounding ST, TK, and AN people entangled in forming the gene pool of Chinese coastal HM people. Genetic findings of isolated shared unique ancestral components based on the sharing alleles and haplotypes deconstructed that HM people from the Yungui Plateau carried the breadth of previously unknown genomic diversity. We identified a direct and recent genetic connection between Chinese inland and Southeast Asian HM people as they shared the most extended identity-by-descent fragments, supporting the long-distance migration hypothesis. Uniparental phylogenetic topology and network-based phylogenetic relationship reconstruction found ancient uniparental founding lineages in southwestern HM people. Finally, the population-specific biological adaptation study identified the shared and differentiated natural selection signatures among inland and coastal HM people associated with physical features and immune functions. The allele frequency spectrum of cancer susceptibility alleles and pharmacogenomic genes showed significant differences between HM and northern Chinese people. Conclusions Our extensive genetic evidence combined with the historical documents supported the view that ancient HM people originated from the Yungui regions associated with ancient “Three-Miao tribes” descended from the ancient Daxi-Qujialing-Shijiahe people. Then, some have recently migrated rapidly to Southeast Asia, and some have migrated eastward and mixed respectively with Southeast Asian indigenes, Liangzhu-related coastal ancient populations, and incoming southward ST people. Generally, complex population migration, admixture, and adaptation history contributed to the complicated patterns of population structure of geographically diverse HM people.

Pathogen‒host adaptative interactions and complex population demographical processes, including admixture, drift, and Darwen selection, have considerably shaped the Neolithic-to-Modern Western Eurasian population structure and genetic susceptibility to modern human diseases. However, the genetic footprints of evolutionary events in East Asia remain unknown due to the underrepresentation of genomic diversity and the design of large-scale population studies. We reported one aggregated database of genome-wide SNP variations from 796 Tai-Kadai (TK) genomes, including that of Bouyei first reported here, to explore the genetic history, population structure, and biological adaptative features of TK people from southern China and Southeast Asia. We found geography-related population substructure among TK people using the state-of-the-art population genetic structure reconstruction techniques based on the allele frequency spectrum and haplotype-resolved phased fragments. We found that the northern TK people from Guizhou harbored one TK-dominant ancestry maximized in the Bouyei people, and the southern TK people from Thailand were more influenced by Southeast Asians and indigenous people. We reconstructed fitted admixture models and demographic graphs, which showed that TK people received gene flow from ancient southern rice farmer-related lineages related to the Hmong-Mien and Austroasiatic people and from northern millet farmers associated with the Sino-Tibetan people. Biological adaptation focused on our identified unique TK lineages related to Bouyei, which showed many adaptive signatures conferring Malaria resistance and low-rate lipid metabolism. Further gene enrichment, the allele frequency distribution of derived alleles, and their correlation with the incidence of Malaria further confirmed that CR1 played an essential role in the resistance of Malaria in the ancient ''Baiyue'' tribes.

ABSTRACTIdentification and the time since deposition (TsD) estimation of body fluid stains from a crime scene could provide valuable information for solving the cases and are always difficult for forensics. Microbial characteristics were considered as a promising biomarker to address the issues. However, changes in the microbiota may damage the specific characteristics of body fluids. Correspondingly, incorrect body fluid identification may result in inaccurate TsD estimation. The mutual influence is not well understood and limited the codetection. In the current study, saliva, semen, vaginal secretion, and menstrual blood samples were exposed to indoor conditions and collected at eight time points (from fresh to 30 days). High-throughput sequencing based on the 16S rRNA gene was performed to characterize the microbial communities. The results showed that a longer TsD could decrease the discrimination of different body fluid stains. However, the accuracies of identification still reached a quite high value even without knowing the TsD. Correspondingly, the mean absolute error (MAE) of TsD estimation significantly increased without distinguishing the types of body fluids. The predictive TsD of menstrual blood reached a quite low MAE (1.54 ± 0.39 d). In comparison, those of saliva (6.57 ± 1.17 d), semen (6.48 ± 1.33 d), and vaginal secretion (5.35 ± 1.11 d) needed to be further improved. The great effect of individual differences on these stains limited the TsD estimation accuracy. Overall, microbial characteristics allow for codetection of body fluid identification and TsD estimation, and body fluids should be identified before estimating TsD in microbiome-based stain analyses.IMPORTANCEEmerged evidences suggest microbial characteristics could be considered a promising tool for identification and time since deposition (TsD) estimation of body fluid stains. However, the two issues should be studied together due to a potential mutual influence. The current study provides the first evidence to understand the mutual influence and determines an optimal process for codetection of identification and TsD estimation for unknown stains for forensics. In addition, we involved aged stains into our study for identification of body fluid stains, rather than only using fresh stains like previous studies. This increased the predictive accuracy. We have preliminary verified that individual differences in microbiotas limited the predictive accuracy of TsD estimation for saliva, semen, and vaginal secretion. Microbial characteristics could provide an accurate TsD estimation for menstrual blood. Our study benefits the comprehensive understanding of microbiome-based stain analyses as an essential addition to previous studies.

Recent advances in next-generation sequencing technologies and improvements in bioinformatics have expanded the scope of microbiome analysis as a forensic tool. Microbiome research is concerned with the study of the compositional profile and diversity of microbial flora as well as the interactions between microbes, hosts, and the environment. It has opened up many new possibilities for forensic analysis. In this review, we discuss various applications of microbiome in forensics, including identification of individuals, geolocation inference, and post-mortem interval (PMI) estimation.

Background: In forensic investigations, accurate estimation of the postmortem interval (PMI) is an important task, but also an ongoing challenge. Especially in cases where the cadaver has been specially treated, for example, by boiling, the determination of PMI becomes extremely difficult. Previous studies have shown that the succession of the microbial community after decomposition of the cadaver can be used to infer PMI. However, the feasibility of determining the PMI of boiled cadavers has not yet been demonstrated. Aims and Objectives: The main objective of this study was to test whether we can infer PMI of boiled cadavers based on the succession of microbial communities. Materials and Methods: SD rats were killed by cervical dislocation. Subsequently, the rat cadavers were divided into the case (boiled cadavers) and control (unboiled cadavers) groups. Rectal samples were collected from the rats for 45 days and at nine time points. High-throughput sequencing of the 16S rRNA gene was performed to characterize the microbial community in the rectum. Results: The results showed that the composition and relative abundance of bacterial communities at the phylum level were significantly different between the case and control groups. The alpha diversity of the microbial community showed a decreasing trend with the decomposition process. Principal coordinate analysis showed that the case and control groups had obvious patterns along the succession of microbial communities. The rectal microbial communities showed a significant linear trend in the time course of decomposition. A random forest model was used to infer PMI. The goodness-of-fit (R2) of the model was 68.00% and 84.00%, and the mean absolute errors were 2.05 and 1.48 days within 45 days of decomposition for the case and control groups, respectively. Conclusions: Our results suggest that microbial community succession could be a potential method to infer PMI of boiled cadavers.

The field of forensic DNA typing, often referred to as “DNA fingerprinting,” has evolved and expanded considerably since its beginnings in the mid-1980s. Originally, forensic DNA typing was primarily used for individual identification and criminal investigations, but it has evolved into a versatile discipline with a wide range of applications. This article addresses the growing scope of forensic genetics, which includes advances in DNA sequencing technologies, mixture analysis, body fluid identification, phenotypic profiling, forensic genealogy, microbiological analysis, exploration of novel markers, and ethical and legal considerations. These developments have enabled the analysis of difficult samples and provided comprehensive insights into the origins of biological evidence. In an ever-evolving landscape, forensic genetics continues to shape the future of forensic science by providing new tools and techniques that help deliver justice in an increasingly complex world.

Prolonged inactivity and disuse conditions, such as those experienced during spaceflight and prolonged bedrest, are frequently accompanied by detrimental effects on the motor system, including skeletal muscle atrophy and bone loss, which greatly increase the risk of osteoporosis and fractures. Moreover, the decrease in glucose and lipid utilization in skeletal muscles, a consequence of muscle atrophy, also contributes to the development of metabolic syndrome. Clarifying the mechanisms involved in disuse-induced musculoskeletal deterioration is important, providing therapeutic targets and a scientific foundation for the treatment of musculoskeletal disorders under disuse conditions. Skeletal muscle, as a powerful endocrine organ, participates in the regulation of physiological and biochemical functions of local or distal tissues and organs, including itself, in endocrine, autocrine, or paracrine manners. As a motor organ adjacent to muscle, bone tissue exhibits a relative lag in degenerative changes compared to skeletal muscle under disuse conditions. Based on this phenomenon, roles and mechanisms involved in the communication between skeletal muscle and bone, especially from muscle to bone, under disuse conditions have attracted widespread attention. In this review, we summarize the roles and regulatory mechanisms of muscle-derived myokines and extracellular vesicles (EVs) in the occurrence of muscle atrophy and bone loss under disuse conditions, as well as discuss future perspectives based on existing research.

Understanding the coal seam gas occurrence law is the premise and foundation of gas disaster prevention and production planning. The tectonic control law and zoning division of gas occurrence in Sichuan Province have been discussed, based on the gradual tectonic control theory for gas occurrence, combined with coal mine gas-geology data and a geological survey in Sichuan Province. The obtained results indicate that the generation, migration, and preservation of gas are controlled by the formation and development, cracking, subduction collision, and intracontinental orogeny of the upper Yangtze block. The gas occurrence and distribution characteristics in Sichuan Province are significant. Gas occurrence of Late Permian coal seams is significantly higher than that of Late Triassic coal seams, as 85.7% of the outburst mines in the Sichuan Province are distributed into the Late Permian coal seams. The Late Permian coal seams in the Xuyong-Junlian superimposed fold belt and Huayingshan detachment fold belt are high gas occurrence zones. These zones had been under strong tectonic compression for several years, thereby resulting in interlayer sliding, formation of stratified tectonic coal, and high degree of coal metamorphism and high gas content, which represent the fundamental reasons why 84.3% of outburst mines in Sichuan Province are located in these two regions. According to the tectonic control law and characteristics of coal seam gas occurrence in Sichuan Province, the gas occurrence zones of coal seam in Sichuan Province were divided into three high gas and outburst zones, three high gas zones and one low gas zone; in addition, their tectonic control characteristics and gas occurrence characteristics were analysed.

Abstract X-chromosome short tandem repeat (X-STR) markers are a powerful complementary system used for paternity and forensic casework. This study presents the development and validation of a new highly efficient multiplex-fluorescent-labeled 19 X-STR typing system, including DXS10079, DXS101, DXS10135, DXS10162, DXS6795, DXS6800, DXS6803, DXS6807, DXS6809, DXS6810, DXS7133, DXS7423, DXS981, DXS9902, DXS9907, GATA165B12, GATA172D05, GATA31E08 and HPRTB along with sex-typing locus, amelogenin. The system was validated according to guidelines issued by the Scientific Working Group on DNA Analysis Methods. Allele frequency and forensic parameters were investigated from 1085 (494 males and 591 females) unrelated Beijing Han individuals, the combined power of discrimination by the 19 X-STR loci in females and males, as well as the combined mean exclusion chance in trios and duos, were 0.999999999999999995, 0.99999999995, 0.9999999995, and 0.9999996, respectively. The results demonstrate that this multiplex system is robust and reliable, and considered to be a powerful tool for forensic application.

The geological structure is complex in the plate margin zone, and the occurrence of coal bed methane (CBM) is nonuniform with an obvious zoning phenomenon. It plays an important role to reveal the spatial distribution of CBM and its influence factors in plate margin zone for CBM exploitation and gas disaster prevention in coal mines. Based on the data of gas emission during mining, CBM content, and gas pressure in the Pingdingshan Coalfield, lying on the south edge of North China plate, the distribution characteristics of CBM and its influence factors using theories of CBM (gas) geology and statistical analysis method are investigated. The research area is divided into four CBM occurrence belts. There are its own CBM occurrence feature and control structural type in each CBM belt. Likou syncline is the structure that controls the overall distribution of CBM. NW-trending fold-fault belt, Guodishan fault, and Jiaxian fault are the structures that control the CBM occurrence in CBM belt IV, CBM belt II, and CBM belt I, respectively. And the difference in structural types is the main factor of CBM zoning.

Abstract Y chromosome Short tandem repeats (Y-STRs) analysis has been widely used in forensic identification, kinship testing, and population evolution. An accurate understanding of haplotype and mutation rate will benefit these applications. In this work, we analyzed 1123 male samples from Northern Chinese Han population which including 578 DNA-confirmed father-son pairs at 22 Y-STRs loci. A total of 537 haplotypes were observed and the overall haplotype diversity was calculated as 1.0000 ± 0.0001. Except that only two haplotypes were observed twice, all the rest of the 535 were unique. Furthermore, totally 47 mutations were observed during 13,872 paternal meiosis. The mutation rate for each locus estimates ranged from 0.0 to 15.6 × 10−3 with an average mutation rate 3.4 × 10−3 (95% CI 2.5–4.5 × 10−3). Among the 22 loci, DYS449, DYS389 II and DYS458 are the most prone to mutations. This study adds to the growing data on Y-STR haplotype diversity and mutation rates and could be very useful for population and forensic genetics.

China is a multinational country composed of 56 ethnic groups of which the Han Chinese accounts for 91.60%. Qinghai Province is located in the northeastern part of the Qinghai–Tibet Plateau, has an area of 72.12 km2, and is the fourth largest province in China. In the present study, we investigated the genetic polymorphisms of 20 short tandem repeat (STR) loci in a Qinghai Han population, as well as its genetic relationships with other populations. A total of 273 alleles were identified in 2 000 individuals at 20 loci, and the allelic frequency ranged from 0.000 2 to 0.532 7. The 20 STR loci showed a relatively high polymorphic rate in the studied group. Observed and expected heterozygosities ranged 0.613 0–0.907 5 and 0.614 8–0.920 0, respectively. The combined power of discrimination, and the probability of exclusion in duo and trio cases were 0.999 999 999 999 999 999 999 999 34, 0.999 996 0 and 0.999 999 996 5, respectively. Analyses of interpopulation differentiation revealed that the most significant differences were found between the Qinghai Han and Malaysian, while no significant differences were found between the Qinghai Han and Han people from Shaanxi and Jiangsu. The results of principal component analysis, multidimensional scaling analysis and phylogenetic reconstructions also suggested the close relationships between the Qinghai Han and other two Han populations. The present results, therefore, indicated that these 20 STR loci could be used for paternity testing and individual identification in forensic applications, and may also provide information for the studies of genetic relationships between Qinghai Han and other groups.

Background: Investigation of allele and genotype frequencies of microsatellite loci in various populations is an essential pre-requisite in forensic application. Aim: The present study obtained population genetic data and forensic parameters of 39 autosomal Short Tandem Repeats (STRs) loci from a Chinese Li ethnic group and estimated the genetic relationships between Li and other reference populations. Subjects and methods: Thirty-nine STR loci, which include D19S433, D5S818, D21S11, D18S51, D6S1043, D3S1358, D13S317, D7S820, D16S539, CSF1PO, Penta D, D2S441, vWA, D8S1179, TPOX, Penta E, TH01, D12S391, D2S1338, FGA, D6S477, D18S535, D19S253, D15S659, D11S2368, D20S470, D1S1656, D22-GATA198B05, D8S1132, D4S2366, D21S1270, D13S325, D9S925, D3S3045, D14S608, D10S1435, D7S3048, D17S1290 and D5S2500, were amplified in two multiplex DNA-STR fluorescence detection systems for 189 unrelated healthy individuals of the Chinese Li ethnic group. The allele frequency distribution and several parameters commonly used in forensic science were statistically analysed. Results: A total of 378 alleles were observed with corresponding allelic frequencies ranging from 0.0026–0.5899. The power of discrimination and power of exclusion ranged from 0.7569–0.9672 and 0.2513–0.7355, respectively. The power of exclusion (PE) ranged from 0.2580–0.7943 for trio paternity cases and 0.1693–0.5940 for duo paternity cases. The polymorphism information content (PIC) ranged from 0.5001–0.8611. The cumulative match probability across these 39 loci was 2.4242 × 10−38. Conclusion: The results indicate that 39 STR loci are polymorphic among the Li ethnic group in Hainan Island in the South China Sea. This set of polymorphic STR loci provide highly polymorphic information and forensic efficiency for forensic individual identification and paternity testing, as well as basic population data for population genetics and anthropological research.

Objective: In a paternity case, the D12S391 locus was reported as a mismatch. To confirm the existence of mutations and mutations come from father or mother. Methods: STR and next-generation sequencing technology were used to validate the sequence. Results: NGS showed the loss of one adenine between the 19.3 allele of the child and allele 20 of the mother. Conclusion: The NGS can be applied in the paternity to validate the mutation.

Next-generation sequencing (NGS) technology, with its high-throughput capacity and low cost, has developed rapidly in recent years and become an important analytical tool for many genomics researchers. New opportunities in the research domain of the forensic studies emerge by harnessing the power of NGS technology, which can be applied to simultaneously analyzing multiple loci of forensic interest in different genetic contexts, such as autosomes, mitochondrial and sex chromosomes. Furthermore, NGS technology can also have potential applications in many other aspects of research. These include DNA database construction, ancestry and phenotypic inference, monozygotic twin studies, body fluid and species identification, and forensic animal, plant and microbiological analyses. Here we review the application of NGS technology in the field of forensic science with the aim of providing a reference for future forensics studies and practice.

Myeloid leukemias are highly diverse diseases and have been shown to be associated with microRNA (miRNA) expression aberrations. The present study involved an in-depth miRNome analysis of two human acute myeloid leukemia (AML) cell lines, HL-60 and THP-1, and one human chronic myeloid leukemia (CML) cell line, K562, via massively parallel signature sequencing. mRNA expression profiles of these cell lines that were established previously in our lab facilitated an integrative analysis of miRNA and mRNA expression patterns. miRNA expression profiling followed by differential expression analysis and target prediction suggested numerous miRNA signatures in AML and CML cell lines. Some miRNAs may act as either tumor suppressors or oncomiRs in AML and CML by targeting key genes in AML and CML pathways. Expression patterns of cell type-specific miRNAs could partially reflect the characteristics of K562, HL-60 and THP-1 cell lines, such as actin filament-based processes, responsiveness to stimulus and phagocytic activity. miRNAs may also regulate myeloid differentiation, since they usually suppress differentiation regulators. Our study provides a resource to further investigate the employment of miRNAs in human leukemia subtyping, leukemogenesis and myeloid development. In addition, the distinctive miRNA signatures may be potential candidates for the clinical diagnosis, prognosis and treatment of myeloid leukemias.

Whole-Genome Bisulfite Sequencing (WGBS) and genome-wide Reduced Representation Bisulfite Sequencing (RRBS) are widely used to study DNA methylation. However, data analysis is complicated, lengthy, and hampered by a lack of seamless analytical pipelines. To address these issues, we developed a convenient, stable, and efficient web service called Web Service for Bisulfite Sequencing Data Analysis (WBSA) to analyze bisulfate sequencing data. WBSA focuses on not only CpG methylation, which is the most common biochemical modification in eukaryotic DNA, but also non-CG methylation, which have been observed in plants, iPS cells, oocytes, neurons and stem cells of human. WBSA comprises three main modules as follows: WGBS data analysis, RRBS data analysis, and differentially methylated region (DMR) identification. The WGBS and RRBS modules execute read mapping, methylation site identification, annotation, and advanced analysis, whereas the DMR module identifies actual DMRs and annotates their correlations to genes. WBSA can be accessed and used without charge either online or local version. WBSA also includes the executables of the Portable Batch System (PBS) and standalone versions that can be downloaded from the website together with the installation instructions. WBSA is available at no charge for academic users at http://wbsa.big.ac.cn.

Since their arrival in the Tibetan Plateau during the Neolithic Age, Tibetans have been well-adapted to extreme environmental conditions and possess genetic variation that reflect their living environment and migratory history. To investigate the origin of Tibetans and the genetic basis of adaptation in a rigorous environment, we genotyped 30 Tibetan individuals with more than one million SNP markers. Our findings suggested that Tibetans, together with the Yi people, were descendants of Tibeto-Burmans who diverged from ancient settlers of East Asia. The valleys of the Hengduan Mountain range may be a major migration route. We also identified a set of positively-selected genes that belong to functional classes of the embryonic, female gonad, and blood vessel developments, as well as response to hypoxia. Most of these genes were highly correlated with population-specific and beneficial phenotypes, such as high infant survival rate and the absence of chronic mountain sickness.