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Williams MP, Flegontov P, Maier R, Huber CD. Testing times: disentangling admixture histories in recent and complex demographies using ancient DNA. Genetics 2024; 228:iyae110. [PMID: 39013011 PMCID: PMC11373510 DOI: 10.1093/genetics/iyae110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 04/08/2024] [Accepted: 06/11/2024] [Indexed: 07/18/2024] Open
Abstract
Our knowledge of human evolutionary history has been greatly advanced by paleogenomics. Since the 2020s, the study of ancient DNA has increasingly focused on reconstructing the recent past. However, the accuracy of paleogenomic methods in resolving questions of historical and archaeological importance amidst the increased demographic complexity and decreased genetic differentiation remains an open question. We evaluated the performance and behavior of two commonly used methods, qpAdm and the f3-statistic, on admixture inference under a diversity of demographic models and data conditions. We performed two complementary simulation approaches-firstly exploring a wide demographic parameter space under four simple demographic models of varying complexities and configurations using branch-length data from two chromosomes-and secondly, we analyzed a model of Eurasian history composed of 59 populations using whole-genome data modified with ancient DNA conditions such as SNP ascertainment, data missingness, and pseudohaploidization. We observe that population differentiation is the primary factor driving qpAdm performance. Notably, while complex gene flow histories influence which models are classified as plausible, they do not reduce overall performance. Under conditions reflective of the historical period, qpAdm most frequently identifies the true model as plausible among a small candidate set of closely related populations. To increase the utility for resolving fine-scaled hypotheses, we provide a heuristic for further distinguishing between candidate models that incorporates qpAdm model P-values and f3-statistics. Finally, we demonstrate a significant performance increase for qpAdm using whole-genome branch-length f2-statistics, highlighting the potential for improved demographic inference that could be achieved with future advancements in f-statistic estimations.
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Affiliation(s)
- Matthew P Williams
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Pavel Flegontov
- Department of Biology and Ecology, University of Ostrava, Ostrava 701 03, Czechia
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Robert Maier
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Christian D Huber
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
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Flegontova O, Işıldak U, Yüncü E, Williams MP, Huber CD, Kočí J, Vyazov LA, Changmai P, Flegontov P. Performance of qpAdm -based screens for genetic admixture on admixture-graph-shaped histories and stepping-stone landscapes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.25.538339. [PMID: 37904998 PMCID: PMC10614728 DOI: 10.1101/2023.04.25.538339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
qpAdm is a statistical tool that is often used in exploratory archaeogenetic studies for finding optimal admixture models of population history. Despite its popularity, qpAdm remains untested on histories in the form of admixture graphs of random topology or stepping-stone landscapes. We analyzed data from such simulations and found that while for admixture-graph-shaped histories there exist simple solutions (temporal stratification) for minimizing false findings of gene flow, in the case of stepping-stone landscapes the method generates results that do not appear suspect but are misleading: feasible qpAdm models are either accurate but simplistic in the context of landscapes, or highly inaccurate in the case of multi-component models. This is largely is due to two reasons: 1) because of complex migration networks that violate the assumptions of the method, there is poor correlation between qpAdm p -values and model optimality in many sections of the parameter space; 2) admixture fraction estimates between 0 and 1 are largely restricted to symmetric source configurations around targets, hence popular [0, 1] model plausibility criteria confound analyses of landscape-type demographies, unless their interpretations are explicitly spatial. For many species/regions/periods archaeogenetic sampling is very sparse and may be random with respect to population density of ancient individuals. In this situation only a specific combination of landscape properties and feasibility criteria allows to efficiently reject highly asymmetric non-optimal models most abundant in random deme sets. This problem may obscure useful signal (rare optimal models) and might be responsible for some claims about rapid long-distance migrations in the literature.
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Yu Y, Yang X, Liu D, Du P, Meng H, Huang Z, Xiong J, Ding Y, Ren X, Allen E, Wang H, Han S, Jin L, Wang CC, Wen S. Ancient genomic analysis of a Chinese hereditary elite from the Northern and Southern Dynasties. J Genet Genomics 2024:S1673-8527(24)00184-X. [PMID: 39009302 DOI: 10.1016/j.jgg.2024.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 07/01/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024]
Abstract
China's Northern and Southern Dynasties period (3rd-6th centuries AD) marked a significant era of ethnic integration in northern China. However, previous ancient DNA studies have primarily focused on northern ethnic groups, with limited research on the genetic formation of the hereditary elite family, especially considering their abundant archaeological record and clear material identity. In this study, we obtained the ancient genome of a hereditary elite family, Gao Bin (, 503-572 AD), at 0.6473-fold coverage with 475132 single-nucleotide polymorphisms (SNPs) on the 1240k panel. His mitochondrial haplogroup belonged to Z4 and Y-haplogroup to O1a1a2b-F2444*. The genetic profile of Gao Bin was most similar to that of the northern Han Chinese. He could be modelled as deriving all his ancestry from Late Neolithic to Iron Age Yellow River farmers without influence from Northeast Asia, Korea, or the Mongolian Plateau. Our study sheds light on the genetic formation of hereditary elite families in the context of the Southern and Northern Dynasties ethnic integration.
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Affiliation(s)
- Yao Yu
- Institute of Archaeological Science, Fudan University, Shanghai 200433, China; Department of History, Fudan University, Shanghai 200433, China
| | - Xiaomin Yang
- Department of Anthropology and Ethnology, Institute of Anthropology, Fujian Provincial Key Laboratory of Philosophy and Social Sciences in Bioanthropology, School of Sociology and Anthropology, Xiamen University, Xiamen, Fujian 361005, China
| | - Daiyun Liu
- Shaanxi Academy of Archaeology, Xi'an, Shaanxi 710054, China
| | - Panxin Du
- Ministry of Education Key Laboratory of Contemporary Anthropology, Department of Anthropology and Human Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China; State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai 200433, China
| | - Hailiang Meng
- Ministry of Education Key Laboratory of Contemporary Anthropology, Department of Anthropology and Human Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Zixiao Huang
- Department of History, Fudan University, Shanghai 200433, China
| | - Jianxue Xiong
- Institute of Archaeological Science, Fudan University, Shanghai 200433, China
| | - Yi Ding
- Institute of Archaeological Science, Fudan University, Shanghai 200433, China
| | - Xiaoying Ren
- Institute of Archaeological Science, Fudan University, Shanghai 200433, China
| | - Edward Allen
- Institute of Archaeological Science, Fudan University, Shanghai 200433, China
| | - Hui Wang
- Center for the Belt and Road Archaeology and Ancient Civilizations, Shanghai 200433, China
| | - Sheng Han
- Department of History, Fudan University, Shanghai 200433, China
| | - Li Jin
- Ministry of Education Key Laboratory of Contemporary Anthropology, Department of Anthropology and Human Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China.
| | - Chuan-Chao Wang
- Department of Anthropology and Ethnology, Institute of Anthropology, Fujian Provincial Key Laboratory of Philosophy and Social Sciences in Bioanthropology, School of Sociology and Anthropology, Xiamen University, Xiamen, Fujian 361005, China; State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; Institute of Artificial Intelligence, Xiamen University, Xiamen, Fujian 361005, China.
| | - Shaoqing Wen
- Institute of Archaeological Science, Fudan University, Shanghai 200433, China; Ministry of Education Key Laboratory of Contemporary Anthropology, Department of Anthropology and Human Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China; Center for the Belt and Road Archaeology and Ancient Civilizations, Shanghai 200433, China; MOE Laboratory for National Development and Intelligent Governance, Fudan University, Shanghai 200433, China.
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Williams MP, Flegontov P, Maier R, Huber CD. Testing Times: Challenges in Disentangling Admixture Histories in Recent and Complex Demographies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.13.566841. [PMID: 38014190 PMCID: PMC10680674 DOI: 10.1101/2023.11.13.566841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Paleogenomics has expanded our knowledge of human evolutionary history. Since the 2020s, the study of ancient DNA has increased its focus on reconstructing the recent past. However, the accuracy of paleogenomic methods in answering questions of historical and archaeological importance amidst the increased demographic complexity and decreased genetic differentiation within the historical period remains an open question. We used two simulation approaches to evaluate the limitations and behavior of commonly used methods, qpAdm and the f3-statistic, on admixture inference. The first is based on branch-length data simulated from four simple demographic models of varying complexities and configurations. The second, an analysis of Eurasian history composed of 59 populations using whole-genome data modified with ancient DNA conditions such as SNP ascertainment, data missingness, and pseudo-haploidization. We show that under conditions resembling historical populations, qpAdm can identify a small candidate set of true sources and populations closely related to them. However, in typical ancient DNA conditions, qpAdm is unable to further distinguish between them, limiting its utility for resolving fine-scaled hypotheses. Notably, we find that complex gene-flow histories generally lead to improvements in the performance of qpAdm and observe no bias in the estimation of admixture weights. We offer a heuristic for admixture inference that incorporates admixture weight estimate and P-values of qpAdm models, and f3-statistics to enhance the power to distinguish between multiple plausible candidates. Finally, we highlight the future potential of qpAdm through whole-genome branch-length f2-statistics, demonstrating the improved demographic inference that could be achieved with advancements in f-statistic estimations.
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Affiliation(s)
- Matthew P. Williams
- Pennsylvania State University, Department of Biology, University Park, PA 16802, USA
| | - Pavel Flegontov
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Robert Maier
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Christian D. Huber
- Pennsylvania State University, Department of Biology, University Park, PA 16802, USA
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Ávila-Arcos MC, Raghavan M, Schlebusch C. Going local with ancient DNA: A review of human histories from regional perspectives. Science 2023; 382:53-58. [PMID: 37797024 DOI: 10.1126/science.adh8140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 09/05/2023] [Indexed: 10/07/2023]
Abstract
Ancient DNA (aDNA) has added a wealth of information about our species' history, including insights on genetic origins, migrations and gene flow, genetic admixture, and health and disease. Much early work has focused on continental-level questions, leaving many regional questions, especially those relevant to the Global South, comparatively underexplored. A few success stories of aDNA studies from smaller laboratories involve more local aspects of human histories and health in the Americas, Africa, Asia, and Oceania. In this Review, we cover some of these contributions by synthesizing finer-scale questions of importance to the archaeogenetics field, as well as to Indigenous and Descendant communities. We further highlight the potential of aDNA to uncover past histories in regions where colonialism has neglected the oral histories of oppressed peoples.
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Affiliation(s)
- María C Ávila-Arcos
- International Laboratory for Human Genome Research, Universidad Nacional Autónoma de México, Querétaro, Mexico
| | - Maanasa Raghavan
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Carina Schlebusch
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
- SciLifeLab, Uppsala, Sweden
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