Fine-Scale Genetic Profile and Admixture History of Two Hmong-Mien-Speaking Miao Tribes from Southwest China Inferred from Genome-Wide Data

As the dominant indigenous minority in Southern China, Hmong-Mien speaking Miao people were thought to be the descendants of Neolithic Yangtze rice farmers. However, the fine-scale population structure and genetic profile of the Miao populations remains unclear due to the limited Miao samples from Southern China and Southeast Asia. Here, we genotyped 19 individuals from the two largest Miao tribes in Guizhou province (Southwest China) via SNP chips and co-analyzed with published available modern and ancient East Asians. We observed that studied Guizhou Miao displayed a closer genomic affinity with present-day and Neolithic-to-Iron Age Southern East Asians than with most Northern East Asians. The genetic substructure within Miao groups was driven by different levels of genetic interaction with other ethnolinguistic groups: Hunan Miao (central China) harbored higher proportions of Northern East Asians-related ancestry; Guizhou Miao (Southwest China) and Vietnam Miao (mainland Southeast Asia) received the additional gene flow mainly from surrounding Tai-Kadai speaking-related ancestry. Besides, there were more complex admixture events between newly studied Guizhou Xijiang Miao and surrounding populations compared with studied Guizhou Congjiang Miao. The qpAdm model further demonstrated that the primary ancestry of Hunan Miao, studied Guizhou Miao and Vietnam Miao derived from ancient Southern East Asian (SEA)-related ancestry (represented by coastal Early Neolithic SEA Liangdao2) with the additional gene flow from ancient northern East Asian-related ancestry (represented by spatiotemporally inland Yellow River farmers), with slightly different proportions. Conclusively, our genomic evidence revealed the complex and distinct demographic history of different Miao tribes

Ancient human genome-wide data from a 3000-year interval in the Caucasus corresponds with eco-geographic regions

该文章报道了高加索地区3000年间的古代族群的遗传结构与生态地理区域的相对应关系，更详尽解析了距今5000多年前的青铜时代早中期以颜那亚（Yamnaya）文化为代表的欧亚草原人群的形成历史。【Abstract】Archaeogenetic studies have described the formation of Eurasian ‘steppe ancestry’ as a mixture of Eastern and Caucasus hunter-gatherers. However, it remains unclear when and where this ancestry arose and whether it was related to a horizon of cultural innovations in the 4th millennium BCE that subsequently facilitated the advance of pastoral societies in Eurasia. Here we generated genome-wide SNP data from 45 prehistoric individuals along a 3000-year temporal transect in the North Caucasus. We observe a genetic separation between the groups of the Caucasus and those of the adjacent steppe. The northern Caucasus groups are genetically similar to contemporaneous populations south of it, suggesting human movement across the mountain range during the Bronze Age. The steppe groups from Yamnaya and subsequent pastoralist cultures show evidence for previously undetected farmer-related ancestry from different contact zones, while Steppe Maykop individuals harbour additional Upper Palaeolithic Siberian and Native American related ancestry.This work was funded by the Max Planck Society, the German Archaeological Institute (DAI; grant no. ERA.Net RUS, BFDJ16011), and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement n° 771234 PALEoRIDER). C.-C.W. was funded by Nanqiang Outstanding Young Talents Program of Xiamen University (X2123302), the Fundamental Research Funds for the Central Universities (ZK1144) and National Natural Science Foundation of China (31801040). E.B. and O.B. were funded by the Russian state task research for RCMG and VIGG

The Impact of Employer Attitude to Green Commuting Plans on Reducing Car Driving: A Mixed Method Analysis

Reducing car trips and promoting green commuting modes are generally considered important solutions to reduce the increase of energy consumption and transportation CO2 emissions. One potential solution for alleviating transportation CO2 emissions has been to identify a role for the employer through green commuter programs. This paper offers an approach to assess the effects of employer attitudes towards green commuting plans on commuter mode choice and the intermediary role car ownership plays in the mode choice decision process. A mixed method which extends the traditional discrete choice model by incorporating latent variables and mediating variables with a structure equation model was used to better understand the commuter mode choice behaviour. The empirical data were selected from Washington-Baltimore Regional Household Travel Survey in 2007-2008, including all the trips from home to workplace during the morning hours. The model parameters were estimated using the simultaneous estimation approach and the integrated model turns out to be superior to the traditional multinomial logit (MNL) model accounting for the impact of employer attitudes towards green commuting. The direct and indirect effects of socio-demographic attributes and employer attitudes towards green commuting were estimated. Through the structural equation modelling with mediating variable, this approach confirmed the intermediary nature of car ownership in the choice process. The results found in this paper provide helpful information for transportation and planning policymakers to test the transportation and planning policies effects and encourage green commuting reducing transportation CO2 emissions.</p

Evaluating the Y chromosomal timescale in human demographic and lineage dating

Y chromosome is a superb tool for inferring human evolution and recent demographic history from a paternal perspective. However, Y chromosomal substitution rates obtained using different modes of calibration vary considerably, and have produced disparate reconstructions of human history. Here, we discuss how substitution rate and date estimates are affected by the choice of different calibration points. We argue that most Y chromosomal substitution rates calculated to date have shortcomings, including a reliance on the ambiguous human-chimpanzee divergence time, insufficient sampling of deep-rooting pedigrees, and using inappropriate founding migrations, although the rates obtained from a single pedigree or calibrated with the peopling of the Americas seem plausible. We highlight the need for using more deep-rooting pedigrees and ancient genomes with reliable dates to improve the rate estimation