Exploring the key deteriorative microorganisms on ancient ivories unearthed from the Sanxingdui Ruins site during temporary cold storage.

Introduction: The ancient ivories unearthed from the Sanxingdui Ruins site are valuable cultural relics, however, the microbial biodeterioration on ivories during temporary cold storage poses a great threat to their later long-term preservation. Methods: Here, the combination of high-throughput sequencing and biochemical assays was applied for the in-depth investigation of the key deteriorative microorganisms colonizing on the ivories and the tracing of their origin, as well as the assessment of the ethanol disinfection impact on the microbial communities on ivories. Results: It was observed that the surfaces of ivories were scattered by the fungal patches of white, dark grey, and hedge green colors during cold storage. The high-throughput sequencing results showed that the genera Mortierella (38.51%), Ilyonectria (14.43%), Penicillium (1.15%), and Aspergillus (1.09%) were the dominant fungi, while Pseudomonas (22.63%), Sphingopyxis (3.06%), and Perlucidibaca (2.92%) were the dominant bacteria on ivories. The isolated Aspergillus A-2 resulted in the highest amount of calcium releasing from the degradation of hydroxyapatite (HAP), the main component of ivory, by the organic acids produced, including oxalic acid and citric acid. The fast expectation-maximization for microbial source tracking (FEAST) analysis revealed that the majority of the fungi (57.45%) and bacteria (71.84%) colonizing on the ivories were derived from the soils surrounding ivories in the sacrifice pits, indicating soils as the primary source for the spoilage microbes growing on ivories. The dominant strains could degrade cellulose, the key components of wet cotton towels commonly applied on ivories for moisture maintenance, aiding the spoilage microbes colonizing on ivories. Notably, the ivory disinfection with 75% ethanol during the cleansing significantly decreased the relative abundance of the dominant genera of Ilyonectria, Aspergillus, and Pseudomonas, with Mortierella becoming the dominant one on ivories. Discussion: Together, the fungi, particularly Aspergillus and Penicillium, played a significant role in the microbial biodeterioration of unearthed ancient ivories by producing the organic acids. These results may improve the control of the microbial biodeterioration and develop more efficient strategies for the long-time conservation of unearthed ancient ivories and other cultural relics.

Ancient genomes reveal millet farming-related demic diffusion from the Yellow River into southwest China.

The study of southwest China is vital for understanding the dispersal and development of farming because of the coexistence of millet and rice in this region since the Neolithic period.1,2 However, the process of the Neolithic transition in southwest China is largely unknown, mainly due to the lack of ancient DNA from the Neolithic period. Here, we report genome-wide data from 11 human samples from the Gaoshan and Haimenkou sites with mixed farming of millet and rice dating to between 4,500 and 3,000 years before present in southwest China. The two ancient groups derived approximately 90% of their ancestry from the Neolithic Yellow River farmers, suggesting a demic diffusion of millet farming to southwest China. We inferred their remaining ancestry to be derived from a Hòabìnhian-related hunter-gatherer lineage. We did not detect rice farmer-related ancestry in the two ancient groups, which indicates that they likely adopted rice farming without genetic assimilation. We, however, observed rice farmer-related ancestry in the formation of some present-day Tibeto-Burman populations. Our results suggested the occurrence of both demic and cultural diffusion in the development of Neolithic mixed farming in some parts of southwest China.

Paleoproteomic evidence reveals dairying supported prehistoric occupation of the highland Tibetan Plateau.

The extreme environments of the Tibetan Plateau offer considerable challenges to human survival, demanding novel adaptations. While the role of biological and agricultural adaptations in enabling early human colonization of the plateau has been widely discussed, the contribution of pastoralism is less well understood, especially the dairy pastoralism that has historically been central to Tibetan diets. Here, we analyze ancient proteins from the dental calculus (n = 40) of all human individuals with sufficient calculus preservation from the interior plateau. Our paleoproteomic results demonstrate that dairy pastoralism began on the highland plateau by ~3500 years ago. Patterns of milk protein recovery point to the importance of dairy for individuals who lived in agriculturally poor regions above 3700 m above sea level. Our study suggests that dairy was a critical cultural adaptation that supported expansion of early pastoralists into the region's vast, non-arable highlands, opening the Tibetan Plateau up to widespread, permanent human occupation.

Human genetic history on the Tibetan Plateau in the past 5100 years.

Using genome-wide data of 89 ancient individuals dated to 5100 to 100 years before the present (B.P.) from 29 sites across the Tibetan Plateau, we found plateau-specific ancestry across plateau populations, with substantial genetic structure indicating high differentiation before 2500 B.P. Northeastern plateau populations rapidly showed admixture associated with millet farmers by 4700 B.P. in the Gonghe Basin. High genetic similarity on the southern and southwestern plateau showed population expansion along the Yarlung Tsangpo River since 3400 years ago. Central and southeastern plateau populations revealed extensive genetic admixture within the plateau historically, with substantial ancestry related to that found in southern and southwestern plateau populations. Over the past ~700 years, substantial gene flow from lowland East Asia further shaped the genetic landscape of present-day plateau populations. The high-altitude adaptive EPAS1 allele was found in plateau populations as early as in a 5100-year-old individual and showed a sharp increase over the past 2800 years.

Maternal genetic history of ancient Tibetans over the past 4,000 years.

The settlement of the Tibetan Plateau epitomizes human adaptation to a high-altitude environment that poses great challenges to human activity. Here, we reconstruct a 4,000-year maternal genetic history of Tibetans using 128 ancient mitochondrial genome data from 37 sites in Tibet. The phylogeny of haplotypes M9a1a, M9a1b, D4g2, G2a'c, and D4i show that ancient Tibetans shared the most recent common ancestor (TMRCA) with ancient Middle and Upper Yellow River populations around the Early and Middle Holocene. In addition, the connections between Tibetans and Northeastern Asians varied over the past 4,000 years, with a stronger matrilineal connection between the two during 4,000-3,000 BP, and a weakened connection after 3,000 BP, that were coincident with climate change, followed by a reinforced connection after the Tubo period (1,400-1,100 BP). Besides, an over 4,000-year matrilineal continuity was observed in some of the maternal lineages. We also found the maternal genetic structure of ancient Tibetans was correlated to the geography and interactions between ancient Tibetans and ancient Nepal and Pakistan populations. Overall, the maternal genetic history of Tibetans can be characterized as a long-term matrilineal continuity with frequent internal and external population interactions that were dynamically shaped by geography, climate changes, as well as historical events.

Genomic history and forensic characteristics of Sherpa highlanders on the Tibetan Plateau inferred from high-resolution InDel panel and genome-wide SNPs.

Sherpa people, one of the high-altitude hypoxic adaptive populations, mainly reside in Nepal and the southern Tibet Autonomous Region. The genetic origin and detailed evolutionary profiles of Sherpas remain to be further explored and comprehensively characterized. Here we analyzed the newly-generated InDel genotype data from 628 Dingjie Sherpas by merging with 4222 worldwide InDel profiles and collected genome-wide SNP data (approximately 600K SNPs) from 1612 individuals in 191 modern and ancient populations to explore and reconstruct the fine-scale genetic structure of Sherpas and their relationships with nearby modern and ancient East Asians based on the shared alleles and haplotypes. The forensic parameters of 57 autosomal InDels (A-InDels) included in our used new-generation InDel amplification system showed that this focused InDel panel is informative and polymorphic in Dingjie Sherpas, suggesting that it can be used as the supplementary tool for forensic personal identification and parentage testing in Dingjie Sherpas. Descriptive findings from the PCA, ADMIXTURE, and TreeMix-based phylogenies suggested that studied Nepal Sherpas showed excess allele sharing with neighboring Tibeto-Burman Tibetans. Furthermore, patterns of allele sharing in f-statistics demonstrated that Nepal Sherpas had a different evolutionary history compared with their neighbors from Nepal (Newar and Gurung) but showed genetic similarity with 2700-year-old Chokhopani and modern Tibet Tibetans. QpAdm/qpGraph-based admixture sources and models further showed that Sherpas, core Tibetans, and Chokhopani formed one clade, which could be fitted as having the main ancestry from late Neolithic Qijia millet farmers and other deep ancestries from early Asians. Chromosome painting profiles and shared IBD fragments inferred from fineSTRUCTURE and ChromoPainter not only confirmed the abovementioned genomic affinity patterns but also revealed the fine-scale genetic microstructures among Sino-Tibetan speakers. Finally, natural-selection signals revealed via iHS, nSL and iHH12 showed natural selection signatures associated with disease susceptibility in Sherpas. Generally, we provided the comprehensive landscape of admixture and evolutionary history of Sherpa people based on the shared alleles and haplotypes from the InDel-based genotype data and high-density genome-wide SNP data. The more detailed genetic landscape of Sherpa people should be further confirmed and characterized via ancient genomes or single-molecule real-time sequencing technology.

An early Holocene human skull from Zhaoguo cave, Southwestern China.

OBJECTIVES: In this study, we describe a newly excavated early Holocene human cranium from Guizhou, Southwestern China, namely the Zhaoguo M1 (ZG 1). We aim to evaluate its morphological resemblance with Late Pleistocene human, and Northern and Southern China Neolithic populations. We also aim to infer its position in the process of East Asian population regionalization. MATERIALS AND METHODS: The ZG 1 skull is almost complete, only missing parts of the right parietal and the basicranium around the foramen magnum. Comparative samples include Late Pleistocene humans and Neolithic populations from Northern and Southern China. Univariate and multivariate analyses are carried out in the study. RESULTS: ZG 1 has a dolichocephalic cranium, wide zygomatic breadth, moderate glabella and supraobtial projection, marked canine fossa, and thin cranial vault. The nasal floor, maximum cranial breadth position, and frontal arc proportion are all congruent with modern human. Statistical analysis suggests that ZG 1's measurements are most similar to those of Southern China Neolithic specimens, with some closer to Late Pleistocene humans. CONCLUSION: ZG 1 shows a clear affinity with Southern China Neolithic populations, providing further support that regionalization of morphological variability patterns between Northern and Southern Neolithic populations could have originated at least 10,000 years ago.

Dietary shifts and diversities of individual life histories reveal cultural dynamics and interplay of millets and rice in the Chengdu Plain, China during the Late Neolithic (2500-2000 cal. BC).

OBJECTIVES: We undertook a more comprehensive analyses than our previous study (Yi et al., International Journal of Osteoarchaeology, 2018, 28, 636-644) at the Gaoshan site (~2500-2000 cal. BC) to expand our understanding of the different roles of rice and millets to human subsistence strategies, diachronic shift of human diets, diversity of human life histories and cultural influence (dental ablation) to human population. MATERIALS AND METHODS: Carbon and nitrogen isotopic analyses of human (ribs and long bones, n = 68) and animal (n = 15) bones as well as carbonized seeds from rice and millets (n = 8) were undertaken. Human bones were directly AMS-14 C dated. In addition, sequential sampling of 16 individuals with varied age and sex and cultural contexts for isotopic analysis was also conducted. RESULTS: The calibrated dating results (n = 27) indicate that there existed two periods of occupation at the site, ~2500-2200 BC and ~2200-1900 BC. Moderate high δ15 N values were found in the crops. Isotopic data from bone collagen suggest that the humans mainly relied on C3 -based animal protein and were supplemented by C4 -based foods. This isotopic pattern is also seen in pigs. Significant difference of human δ13 C values (Mann-Whitney U test, p < 0.05) between the two periods was observed. Compared to the bones, the isotopic data of human dentine serial sections show a much wider variability and higher δ13 C values. DISCUSSION: The crops (millets and rice) were probably manured. Human individuals subsisted on rice/millet agriculture and pigs in general. In combination with the radiocarbon dates, the increase of C3 (rice) consumption by the humans was found from the early (2500-2200 cal. BC) to late (2200-2000 cal. BC) periods, indicating the intensification of rice agriculture through time. However, four categories of human life histories during childhood are identified given different isotopic profiles of dentine sections, demonstrating that C3 (rice) and C4 (millets)-based foods played different roles in human lives. Even though, there were similar weaning practices among the human populations. It is surprising that human individuals with dental ablation, cultural characteristic in the Middle and Lower Yangtze River Valley, consumed more millets during childhood in the early period than those without dental ablation in the late period. Our study here provides novel insights into cultural dynamics and the interplay between rice and millets in rice-millet agricultural system during the Late Neolithic in Southwest China.

Genetic substructure and admixture of Mongolians and Kazakhs inferred from genome-wide array genotyping.

BACKGROUND: Mongolian populations are widely distributed geographically, showing abundant ethnic diversity with geographic and tribal differences. AIM: To infer the genetic substructure, admixture and ancient genetic sources of Mongolians together with Kazakhs. SUBJECTS AND METHODS: We genotyped more than 690,000 genome-wide SNPs from 33 Mongolian and Chinese Kazakh individuals and compared these with both ancient and present-day Eurasian populations using Principal Component Analysis (PCA), ADMIXTURE, Refine-IBD, f statistics, qpWave and qpAdm. RESULTS: We found genetic substructures within Mongolians corresponding to Ölöd, Chahar, and Inner Mongolian clusters, which was consistent with tribe classifications. Mongolian and Kazakh groups derived about 6-40% of West Eurasian related ancestry, most likely from Bronze Age Steppe populations. The East Asian related ancestry in Mongolian and Kazakh groups was well represented by the Neolithic DevilsCave related nomadic lineage, comprising 42-64% of studied groups. We also detected 10-51% of Han Chinese related ancestry in Mongolian and Kazakh groups, especially in Inner Mongolians. The average admixture times for Inner Mongolian, Mongolian_Chahar, Mongolian_Ölöd and Chinese Kazakh were about 1381, 626, 635 and 632 years ago, respectively, with Han and French as the sources. CONCLUSION: The DevilsCave related ancestry was once widespread westwards covering a wide geographical range from Far East Russia to the Mongolia Plateau. The formation of present-day Mongolic and Turkic-speaking populations has also received genetic influence from agricultural expansion.

The upper limb skeleton and behavioral lateralization of modern humans from Zhaoguo Cave, southwestern China.

OBJECTIVES: Aims of the study are to initially describe and comparatively evaluate the morphology of the new Zhaoguo M1 upper limb remains, and contextualize upper limb functional adaptations among those of other worldwide Upper Paleolithic (UP) humans to make inferences about subsistence-related activity patterns in southwestern China at the Pleistocene-Holocene boundary. MATERIALS AND METHODS: The preserved Zhaoguo M1 skeletal remains include paired humeri, ulnae, and radii, among others. These specimens were scanned using micro-computed tomography to evaluate internal structural properties, while external osteometric dimensions of the Zhaoguo M1 upper limb elements also were acquired. Both sets of measurements were compared to published data on Neandertals, and Middle and Upper Paleolithic modern humans. RESULTS: The upper limb elements of Zhaoguo M1 display a suite of characteristics that generally resemble those of other contemporary Late UP (LUP) modern humans, while robusticity indices generally fall within the upper range of LUP variation. The Zhaoguo M1 upper limb elements display fewer traits resembling those of late archaic humans. The Zhaoguo M1 individual exhibits diaphyseal asymmetry in several upper limb elements suggesting left hand dominance. When evaluating the full range of magnitudes of humeral bilateral asymmetry in the comparative sample, Zhaoguo M1 falls at the lower end overall, but yet is relatively higher than contemporary LUP modern humans specifically from East Eurasia. DISCUSSION: The Zhaoguo M1 individual suggests typical LUP modern human upper limb morphology persisted in southwest China until the end of the last glacial period. Upper limb bone asymmetry of Zhaoguo M1 also indicates that behavioral activities attributed to a hunter-gatherer tradition apparently extended through the Pleistocene-Holocene transition in this region.

Ancient mitogenomes show plateau populations from last 5200 years partially contributed to present-day Tibetans.

The clarification of the genetic origins of present-day Tibetans requires an understanding of their past relationships with the ancient populations of the Tibetan Plateau. Here we successfully sequenced 67 complete mitochondrial DNA genomes of 5200 to 300-year-old humans from the plateau. Apart from identifying two ancient plateau lineages (haplogroups D4j1b and M9a1a1c1b1a) that suggest some ancestors of Tibetans came from low-altitude areas 4750 to 2775 years ago and that some were involved in an expansion of people moving between high-altitude areas 2125 to 1100 years ago, we found limited evidence of recent matrilineal continuity on the plateau. Furthermore, deep learning of the ancient data incorporated into simulation models with an accuracy of 97% supports that present-day Tibetan matrilineal ancestry received partial contribution rather than complete continuity from the plateau populations of the last 5200 years.

Ancient DNA Evidence from China Reveals the Expansion of Pacific Dogs.

The ancestral homeland of Australian dingoes and Pacific dogs is proposed to be in South China. However, the location and timing of their dispersal and relationship to dog domestication is unclear. Here, we sequenced 7,000- to 2,000-year-old complete mitochondrial DNA (mtDNA) genomes of 27 ancient canids (one gray wolf and 26 domestic dogs) from the Yellow River and Yangtze River basins (YYRB). These are the first complete ancient mtDNA of Chinese dogs from the cradle of early Chinese civilization. We found that most ancient dogs (18/26) belong to the haplogroup A1b lineage that is found in high frequency in present-day Australian dingoes and precolonial Pacific Island dogs but low frequency in present-day China. Particularly, a 7,000-year-old dog from the Tianluoshan site in Zhejiang province possesses a haplotype basal to the entire haplogroup A1b lineage. We propose that A1b lineage dogs were once widely distributed in the YYRB area. Following their dispersal to South China, and then into Southeast Asia, New Guinea and remote Oceania, they were largely replaced by dogs belonging to other lineages in the last 2,000 years in present-day China, especially North China.