1
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Wong Y, Ignatieva A, Koskela J, Gorjanc G, Wohns AW, Kelleher J. A general and efficient representation of ancestral recombination graphs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.03.565466. [PMID: 37961279 PMCID: PMC10635123 DOI: 10.1101/2023.11.03.565466] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
As a result of recombination, adjacent nucleotides can have different paths of genetic inheritance and therefore the genealogical trees for a sample of DNA sequences vary along the genome. The structure capturing the details of these intricately interwoven paths of inheritance is referred to as an ancestral recombination graph (ARG). Classical formalisms have focused on mapping coalescence and recombination events to the nodes in an ARG. This approach is out of step with modern developments, which do not represent genetic inheritance in terms of these events or explicitly infer them. We present a simple formalism that defines an ARG in terms of specific genomes and their intervals of genetic inheritance, and show how it generalises these classical treatments and encompasses the outputs of recent methods. We discuss nuances arising from this more general structure, and argue that it forms an appropriate basis for a software standard in this rapidly growing field.
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Affiliation(s)
- Yan Wong
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, UK
| | - Anastasia Ignatieva
- School of Mathematics and Statistics, University of Glasgow, UK
- Department of Statistics, University of Oxford, UK
| | - Jere Koskela
- School of Mathematics, Statistics and Physics, Newcastle University, UK
- Department of Statistics, University of Warwick, UK
| | - Gregor Gorjanc
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK
| | - Anthony W. Wohns
- Broad Institute of MIT and Harvard, Cambridge, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, USA
| | - Jerome Kelleher
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, UK
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2
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Brandt DYC, Huber CD, Chiang CWK, Ortega-Del Vecchyo D. The Promise of Inferring the Past Using the Ancestral Recombination Graph. Genome Biol Evol 2024; 16:evae005. [PMID: 38242694 PMCID: PMC10834162 DOI: 10.1093/gbe/evae005] [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: 05/31/2023] [Revised: 12/11/2023] [Accepted: 12/17/2023] [Indexed: 01/21/2024] Open
Abstract
The ancestral recombination graph (ARG) is a structure that represents the history of coalescent and recombination events connecting a set of sequences (Hudson RR. In: Futuyma D, Antonovics J, editors. Gene genealogies and the coalescent process. In: Oxford Surveys in Evolutionary Biology; 1991. p. 1 to 44.). The full ARG can be represented as a set of genealogical trees at every locus in the genome, annotated with recombination events that change the topology of the trees between adjacent loci and the mutations that occurred along the branches of those trees (Griffiths RC, Marjoram P. An ancestral recombination graph. In: Donnelly P, Tavare S, editors. Progress in population genetics and human evolution. Springer; 1997. p. 257 to 270.). Valuable insights can be gained into past evolutionary processes, such as demographic events or the influence of natural selection, by studying the ARG. It is regarded as the "holy grail" of population genetics (Hubisz M, Siepel A. Inference of ancestral recombination graphs using ARGweaver. In: Dutheil JY, editors. Statistical population genomics. New York, NY: Springer US; 2020. p. 231-266.) since it encodes the processes that generate all patterns of allelic and haplotypic variation from which all commonly used summary statistics in population genetic research (e.g. heterozygosity and linkage disequilibrium) can be derived. Many previous evolutionary inferences relied on summary statistics extracted from the genotype matrix. Evolutionary inferences using the ARG represent a significant advancement as the ARG is a representation of the evolutionary history of a sample that shows the past history of recombination, coalescence, and mutation events across a particular sequence. This representation in theory contains as much information, if not more, than the combination of all independent summary statistics that could be derived from the genotype matrix. Consistent with this idea, some of the first ARG-based analyses have proven to be more powerful than summary statistic-based analyses (Speidel L, Forest M, Shi S, Myers SR. A method for genome-wide genealogy estimation for thousands of samples. Nat Genet. 2019:51(9):1321 to 1329.; Stern AJ, Wilton PR, Nielsen R. An approximate full-likelihood method for inferring selection and allele frequency trajectories from DNA sequence data. PLoS Genet. 2019:15(9):e1008384.; Hubisz MJ, Williams AL, Siepel A. Mapping gene flow between ancient hominins through demography-aware inference of the ancestral recombination graph. PLoS Genet. 2020:16(8):e1008895.; Fan C, Mancuso N, Chiang CWK. A genealogical estimate of genetic relationships. Am J Hum Genet. 2022:109(5):812-824.; Fan C, Cahoon JL, Dinh BL, Ortega-Del Vecchyo D, Huber C, Edge MD, Mancuso N, Chiang CWK. A likelihood-based framework for demographic inference from genealogical trees. bioRxiv. 2023.10.10.561787. 2023.; Hejase HA, Mo Z, Campagna L, Siepel A. A deep-learning approach for inference of selective sweeps from the ancestral recombination graph. Mol Biol Evol. 2022:39(1):msab332.; Link V, Schraiber JG, Fan C, Dinh B, Mancuso N, Chiang CWK, Edge MD. Tree-based QTL mapping with expected local genetic relatedness matrices. bioRxiv. 2023.04.07.536093. 2023.; Zhang BC, Biddanda A, Gunnarsson ÁF, Cooper F, Palamara PF. Biobank-scale inference of ancestral recombination graphs enables genealogical analysis of complex traits. Nat Genet. 2023:55(5):768-776.). As such, there has been significant interest in the field to investigate 2 main problems related to the ARG: (i) How can we estimate the ARG based on genomic data, and (ii) how can we extract information of past evolutionary processes from the ARG? In this perspective, we highlight 3 topics that pertain to these main issues: The development of computational innovations that enable the estimation of the ARG; remaining challenges in estimating the ARG; and methodological advances for deducing evolutionary forces and mechanisms using the ARG. This perspective serves to introduce the readers to the types of questions that can be explored using the ARG and to highlight some of the most pressing issues that must be addressed in order to make ARG-based inference an indispensable tool for evolutionary research.
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Affiliation(s)
- Débora Y C Brandt
- Department of Genetics Evolution and Environment, University College London, London, UK
| | - Christian D Huber
- Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Charleston W K Chiang
- Center for Genetic Epidemiology, Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Diego Ortega-Del Vecchyo
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma De México, Querétaro, Querétaro, Mexico
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3
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Peyrégne S, Slon V, Kelso J. More than a decade of genetic research on the Denisovans. Nat Rev Genet 2024; 25:83-103. [PMID: 37723347 DOI: 10.1038/s41576-023-00643-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2023] [Indexed: 09/20/2023]
Abstract
Denisovans, a group of now extinct humans who lived in Eastern Eurasia in the Middle and Late Pleistocene, were first identified from DNA sequences just over a decade ago. Only ten fragmentary remains from two sites have been attributed to Denisovans based entirely on molecular information. Nevertheless, there has been great interest in using genetic data to understand Denisovans and their place in human history. From the reconstruction of a single high-quality genome, it has been possible to infer their population history, including events of admixture with other human groups. Additionally, the identification of Denisovan DNA in the genomes of present-day individuals has provided insights into the timing and routes of dispersal of ancient modern humans into Asia and Oceania, as well as the contributions of archaic DNA to the physiology of present-day people. In this Review, we synthesize more than a decade of research on Denisovans, reconcile controversies and summarize insights into their population history and phenotype. We also highlight how our growing knowledge about Denisovans has provided insights into our own evolutionary history.
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Affiliation(s)
- Stéphane Peyrégne
- Department of Evolutionary Genetics, Max-Planck-Institute for Evolutionary Anthropology, Leipzig, Germany.
| | - Viviane Slon
- Department of Evolutionary Genetics, Max-Planck-Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Anatomy and Anthropology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Dan David Center for Human Evolution and Biohistory Research, Tel Aviv University, Tel Aviv, Israel
| | - Janet Kelso
- Department of Evolutionary Genetics, Max-Planck-Institute for Evolutionary Anthropology, Leipzig, Germany.
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4
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Lewanski AL, Grundler MC, Bradburd GS. The era of the ARG: An introduction to ancestral recombination graphs and their significance in empirical evolutionary genomics. PLoS Genet 2024; 20:e1011110. [PMID: 38236805 PMCID: PMC10796009 DOI: 10.1371/journal.pgen.1011110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2024] Open
Abstract
In the presence of recombination, the evolutionary relationships between a set of sampled genomes cannot be described by a single genealogical tree. Instead, the genomes are related by a complex, interwoven collection of genealogies formalized in a structure called an ancestral recombination graph (ARG). An ARG extensively encodes the ancestry of the genome(s) and thus is replete with valuable information for addressing diverse questions in evolutionary biology. Despite its potential utility, technological and methodological limitations, along with a lack of approachable literature, have severely restricted awareness and application of ARGs in evolution research. Excitingly, recent progress in ARG reconstruction and simulation have made ARG-based approaches feasible for many questions and systems. In this review, we provide an accessible introduction and exploration of ARGs, survey recent methodological breakthroughs, and describe the potential for ARGs to further existing goals and open avenues of inquiry that were previously inaccessible in evolutionary genomics. Through this discussion, we aim to more widely disseminate the promise of ARGs in evolutionary genomics and encourage the broader development and adoption of ARG-based inference.
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Affiliation(s)
- Alexander L. Lewanski
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, United States of America
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, United States of America
- Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, Michigan, United States of America
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Michael C. Grundler
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Gideon S. Bradburd
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, United States of America
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
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5
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Wroblewski TH, Witt KE, Lee SB, Malhi RS, Peede D, Huerta-Sánchez E, Villanea FA, Claw KG. Pharmacogenetic Variation in Neanderthals and Denisovans and Implications for Human Health and Response to Medications. Genome Biol Evol 2023; 15:evad222. [PMID: 38051947 PMCID: PMC10727477 DOI: 10.1093/gbe/evad222] [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: 04/03/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 12/07/2023] Open
Abstract
Modern humans carry both Neanderthal and Denisovan (archaic) genome elements that are part of the human gene pool and affect the life and health of living individuals. The impact of archaic DNA may be particularly evident in pharmacogenes-genes responsible for the processing of exogenous substances such as food, pollutants, and medications-as these can relate to changing environmental effects, and beneficial variants may have been retained as modern humans encountered new environments. However, the health implications and contribution of archaic ancestry in pharmacogenes of modern humans remain understudied. Here, we explore 11 key cytochrome P450 genes (CYP450) involved in 75% of all drug metabolizing reactions in three Neanderthal and one Denisovan individuals and examine archaic introgression in modern human populations. We infer the metabolizing efficiency of these 11 CYP450 genes in archaic individuals and find important predicted phenotypic differences relative to modern human variants. We identify several single nucleotide variants shared between archaic and modern humans in each gene, including some potentially function-altering mutations in archaic CYP450 genes, which may result in altered metabolism in living people carrying these variants. We also identified several variants in the archaic CYP450 genes that are novel and unique to archaic humans as well as one gene, CYP2B6, that shows evidence for a gene duplication found only in Neanderthals and modern Africans. Finally, we highlight CYP2A6, CYP2C9, and CYP2J2, genes which show evidence for archaic introgression into modern humans and posit evolutionary hypotheses that explain their allele frequencies in modern populations.
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Affiliation(s)
- Tadeusz H Wroblewski
- Department of Biomedical Informatics, Colorado Center for Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Kelsey E Witt
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, South Carolina, USA
| | - Seung-been Lee
- Precision Medicine Institute, Macrogen Inc., Seoul, Republic of Korea
| | - Ripan S Malhi
- Department of Anthropology and Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Illinois, USA
| | - David Peede
- Department of Ecology, Evolution, and Organismal Biology and Center for Computational and Molecular Biology, Brown University, Providence, Rhode Island, USA
- Institute at Brown for Environment and Society, Brown University, Providence, Rhode Island, USA
| | - Emilia Huerta-Sánchez
- Department of Ecology, Evolution, and Organismal Biology and Center for Computational and Molecular Biology, Brown University, Providence, Rhode Island, USA
| | | | - Katrina G Claw
- Department of Biomedical Informatics, Colorado Center for Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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6
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Ragsdale AP. Human evolution: Neanderthal footprints in African genomes. Curr Biol 2023; 33:R1197-R1200. [PMID: 37989099 DOI: 10.1016/j.cub.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Human and Neanderthal populations met and mixed on multiple occasions over evolutionary time, resulting in the exchange of genetic material. New genomic analyses of diverse African populations reveal a history of bidirectional gene flow and selection acting on introgressed alleles.
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Affiliation(s)
- Aaron P Ragsdale
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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7
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Harris DN, Platt A, Hansen MEB, Fan S, McQuillan MA, Nyambo T, Mpoloka SW, Mokone GG, Belay G, Fokunang C, Njamnshi AK, Tishkoff SA. Diverse African genomes reveal selection on ancient modern human introgressions in Neanderthals. Curr Biol 2023; 33:4905-4916.e5. [PMID: 37837965 PMCID: PMC10841429 DOI: 10.1016/j.cub.2023.09.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/18/2023] [Accepted: 09/26/2023] [Indexed: 10/16/2023]
Abstract
Comparisons of Neanderthal genomes to anatomically modern human (AMH) genomes show a history of Neanderthal-to-AMH introgression stemming from interbreeding after the migration of AMHs from Africa to Eurasia. All non-sub-Saharan African AMHs have genomic regions genetically similar to Neanderthals that descend from this introgression. Regions of the genome with Neanderthal similarities have also been identified in sub-Saharan African populations, but their origins have been unclear. To better understand how these regions are distributed across sub-Saharan Africa, the source of their origin, and what their distribution within the genome tells us about early AMH and Neanderthal evolution, we analyzed a dataset of high-coverage, whole-genome sequences from 180 individuals from 12 diverse sub-Saharan African populations. In sub-Saharan African populations with non-sub-Saharan African ancestry, as much as 1% of their genomes can be attributed to Neanderthal sequence introduced by recent migration, and subsequent admixture, of AMH populations originating from the Levant and North Africa. However, most Neanderthal homologous regions in sub-Saharan African populations originate from migration of AMH populations from Africa to Eurasia ∼250 kya, and subsequent admixture with Neanderthals, resulting in ∼6% AMH ancestry in Neanderthals. These results indicate that there have been multiple migration events of AMHs out of Africa and that Neanderthal and AMH gene flow has been bi-directional. Observing that genomic regions where AMHs show a depletion of Neanderthal introgression are also regions where Neanderthal genomes show a depletion of AMH introgression points to deleterious interactions between introgressed variants and background genomes in both groups-a hallmark of incipient speciation.
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Affiliation(s)
- Daniel N Harris
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexander Platt
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew E B Hansen
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shaohua Fan
- State Key Laboratory of Genetic Engineering, Human Phenome Institute, Zhangjiang Fudan International Innovation Center, School of Life Science, Fudan University, Shanghai 200438, China
| | - Michael A McQuillan
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Thomas Nyambo
- Department of Biochemistry and Molecular Biology, Hubert Kairuki Memorial University, Dar es Salaam, Tanzania
| | - Sununguko Wata Mpoloka
- Department of Biological Sciences, Faculty of Science, University of Botswana, Private Bag UB 0022, Gaborone, Botswana
| | - Gaonyadiwe George Mokone
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Private Bag UB 0022, Gaborone, Botswana
| | - Gurja Belay
- Department of Microbial Cellular and Molecular Biology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Charles Fokunang
- Department of Pharmacotoxicology and Pharmacokinetics, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Alfred K Njamnshi
- Brain Research Africa Initiative (BRAIN), P.O. Box 25625, Yaoundé, Cameroon; Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon
| | - Sarah A Tishkoff
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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8
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Rasmussen DA, Guo F. Espalier: Efficient Tree Reconciliation and Ancestral Recombination Graphs Reconstruction Using Maximum Agreement Forests. Syst Biol 2023; 72:1154-1170. [PMID: 37458753 PMCID: PMC10627558 DOI: 10.1093/sysbio/syad040] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 06/26/2023] [Accepted: 06/30/2023] [Indexed: 11/08/2023] Open
Abstract
In the presence of recombination individuals may inherit different regions of their genome from different ancestors, resulting in a mosaic of phylogenetic histories across their genome. Ancestral recombination graphs (ARGs) can capture how phylogenetic relationships vary across the genome due to recombination, but reconstructing ARGs from genomic sequence data is notoriously difficult. Here, we present a method for reconciling discordant phylogenetic trees and reconstructing ARGs using maximum agreement forests (MAFs). Given two discordant trees, a MAF identifies the smallest possible set of topologically concordant subtrees present in both trees. We show how discordant trees can be reconciled through their MAF in a way that retains discordances strongly supported by sequence data while eliminating conflicts likely attributable to phylogenetic noise. We further show how MAFs and our reconciliation approach can be combined to select a path of local trees across the genome that maximizes the likelihood of the genomic sequence data, minimizes discordance between neighboring local trees, and identifies the recombination events necessary to explain remaining discordances to obtain a fully connected ARG. While heuristic, our ARG reconstruction approach is often as accurate as more exact methods while being much more computationally efficient. Moreover, important demographic parameters such as recombination rates can be accurately estimated from reconstructed ARGs. Finally, we apply our approach to plant infecting RNA viruses in the genus Potyvirus to demonstrate how true recombination events can be disentangled from phylogenetic noise using our ARG reconstruction methods.
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Affiliation(s)
- David A Rasmussen
- Department of Entomology and Plant Pathology, North Carolina State University, Campus Box 7613, Raleigh, NC 27695, USA
- Bioinformatics Research Center, North Carolina State University, Campus Box 7566, Raleigh, NC 27695, USA
| | - Fangfang Guo
- Department of Entomology and Plant Pathology, North Carolina State University, Campus Box 7613, Raleigh, NC 27695, USA
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9
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Lewanski AL, Grundler MC, Bradburd GS. The era of the ARG: an empiricist's guide to ancestral recombination graphs. ARXIV 2023:arXiv:2310.12070v1. [PMID: 37904740 PMCID: PMC10614969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
In the presence of recombination, the evolutionary relationships between a set of sampled genomes cannot be described by a single genealogical tree. Instead, the genomes are related by a complex, interwoven collection of genealogies formalized in a structure called an ancestral recombination graph (ARG). An ARG extensively encodes the ancestry of the genome(s) and thus is replete with valuable information for addressing diverse questions in evolutionary biology. Despite its potential utility, technological and methodological limitations, along with a lack of approachable literature, have severely restricted awareness and application of ARGs in empirical evolution research. Excitingly, recent progress in ARG reconstruction and simulation have made ARG-based approaches feasible for many questions and systems. In this review, we provide an accessible introduction and exploration of ARGs, survey recent methodological breakthroughs, and describe the potential for ARGs to further existing goals and open avenues of inquiry that were previously inaccessible in evolutionary genomics. Through this discussion, we aim to more widely disseminate the promise of ARGs in evolutionary genomics and encourage the broader development and adoption of ARG-based inference.
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Affiliation(s)
- Alexander L Lewanski
- Department of Integrative Biology, Michigan State University, East Lansing, MI, US
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, US
- Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI, US
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, US
| | - Michael C Grundler
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, US
| | - Gideon S Bradburd
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, US
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, US
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10
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Villanea FA, Peede D, Kaufman EJ, Añorve-Garibay V, Witt KE, Villa-Islas V, Zeloni R, Marnetto D, Moorjani P, Jay F, Valdmanis PN, Ávila-Arcos MC, Huerta-Sánchez E. The MUC19 gene in Denisovans, Neanderthals, and Modern Humans: An Evolutionary History of Recurrent Introgression and Natural Selection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.25.559202. [PMID: 37808839 PMCID: PMC10557577 DOI: 10.1101/2023.09.25.559202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
All humans carry a small fraction of archaic ancestry across the genome, the legacy of gene flow from Neanderthals, Denisovans, and other hominids into the ancestors of modern humans. While the effects of Neanderthal ancestry on human fitness and health have been explored more thoroughly, there are fewer examples of adaptive introgression of Denisovan variants. Here, we study the gene MUC19, for which some modern humans carry a Denisovan-like haplotype. MUC19 is a mucin, a glycoprotein that forms gels with various biological functions, from lubrication to immunity. We find the diagnostic variants for the Denisovan-like MUC19 haplotype at high frequencies in admixed Latin American individuals among global population, and at highest frequency in 23 ancient Indigenous American individuals, all predating population admixture with Europeans and Africans. We find that some Neanderthals--Vindija and Chagyrskaya--carry the Denisovan-like MUC19 haplotype, and that it was likely introgressed into human populations through Neanderthal introgression rather than Denisovan introgression. Finally, we find that the Denisovan-like MUC19 haplotype carries a higher copy number of a 30 base-pair variable number tandem repeat relative to the Human-like haplotype, and that copy numbers of this repeat are exceedingly high in American populations. Our results suggest that the Denisovan-like MUC19 haplotype served as the raw genetic material for positive selection as American populations adapted to novel environments during their movement from Beringia into North and then South America.
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Affiliation(s)
| | - David Peede
- Department of Ecology, Evolution, and Organismal Biology, Brown University
- Center for Computational Molecular Biology, Brown University
- Institute at Brown for Environment and Society, Brown University
| | - Eli J Kaufman
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine
| | - Valeria Añorve-Garibay
- Center for Computational Molecular Biology, Brown University
- International Laboratory for Human Genome Research, Universidad Nacional Autónoma de México
| | - Kelsey E Witt
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University
| | - Viridiana Villa-Islas
- International Laboratory for Human Genome Research, Universidad Nacional Autónoma de México
| | - Roberta Zeloni
- Department of Neurosciences "Rita Levi Montalcini", University of Turin
| | - Davide Marnetto
- Department of Neurosciences "Rita Levi Montalcini", University of Turin
| | - Priya Moorjani
- Department of Molecular and Cell Biology, University of California, Berkeley
- Center for Computational Biology, University of California, Berkeley
| | - Flora Jay
- Université Paris-Saclay, CNRS, INRIA, Laboratoire Interdisciplinaire des Sciences du Numérique, 91400, Orsay, France
| | - Paul N Valdmanis
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine
| | - María C Ávila-Arcos
- International Laboratory for Human Genome Research, Universidad Nacional Autónoma de México
| | - Emilia Huerta-Sánchez
- Department of Ecology, Evolution, and Organismal Biology, Brown University
- Center for Computational Molecular Biology, Brown University
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11
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Roca-Umbert A, Garcia-Calleja J, Vogel-González M, Fierro-Villegas A, Ill-Raga G, Herrera-Fernández V, Bosnjak A, Muntané G, Gutiérrez E, Campelo F, Vicente R, Bosch E. Human genetic adaptation related to cellular zinc homeostasis. PLoS Genet 2023; 19:e1010950. [PMID: 37747921 PMCID: PMC10553801 DOI: 10.1371/journal.pgen.1010950] [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: 02/28/2023] [Revised: 10/05/2023] [Accepted: 08/31/2023] [Indexed: 09/27/2023] Open
Abstract
SLC30A9 encodes a ubiquitously zinc transporter (ZnT9) and has been consistently suggested as a candidate for positive selection in humans. However, no direct adaptive molecular phenotype has been demonstrated. Our results provide evidence for directional selection operating in two major complementary haplotypes in Africa and East Asia. These haplotypes are associated with differential gene expression but also differ in the Met50Val substitution (rs1047626) in ZnT9, which we show is found in homozygosis in the Denisovan genome and displays accompanying signatures suggestive of archaic introgression. Although we found no significant differences in systemic zinc content between individuals with different rs1047626 genotypes, we demonstrate that the expression of the derived isoform (ZnT9 50Val) in HEK293 cells shows a gain of function when compared with the ancestral (ZnT9 50Met) variant. Notably, the ZnT9 50Val variant was found associated with differences in zinc handling by the mitochondria and endoplasmic reticulum, with an impact on mitochondrial metabolism. Given the essential role of the mitochondria in skeletal muscle and since the derived allele at rs1047626 is known to be associated with greater susceptibility to several neuropsychiatric traits, we propose that adaptation to cold may have driven this selection event, while also impacting predisposition to neuropsychiatric disorders in modern humans.
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Affiliation(s)
- Ana Roca-Umbert
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
| | - Jorge Garcia-Calleja
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
| | - Marina Vogel-González
- Laboratory of Molecular Physiology, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, Barcelona, Spain
| | - Alejandro Fierro-Villegas
- Laboratory of Molecular Physiology, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, Barcelona, Spain
| | - Gerard Ill-Raga
- Laboratory of Molecular Physiology, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, Barcelona, Spain
| | - Víctor Herrera-Fernández
- Laboratory of Molecular Physiology, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, Barcelona, Spain
| | - Anja Bosnjak
- Laboratory of Molecular Physiology, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, Barcelona, Spain
| | - Gerard Muntané
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
- Hospital Universitari Institut Pere Mata, IISPV, Universitat Rovira i Virgili, Reus, Spain
- Centro de Investigación Biomédica en Red de Salud Mental, Instituto de Salud Carlos III, Madrid, Spain
| | - Esteban Gutiérrez
- Laboratory of Molecular Physiology, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, Barcelona, Spain
| | - Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Rubén Vicente
- Laboratory of Molecular Physiology, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, Barcelona, Spain
| | - Elena Bosch
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Salud Mental, Instituto de Salud Carlos III, Madrid, Spain
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12
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Flegontov P, Işıldak U, Maier R, Yüncü E, Changmai P, Reich D. Modeling of African population history using f-statistics is biased when applying all previously proposed SNP ascertainment schemes. PLoS Genet 2023; 19:e1010931. [PMID: 37676865 PMCID: PMC10508636 DOI: 10.1371/journal.pgen.1010931] [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: 01/22/2023] [Revised: 09/19/2023] [Accepted: 08/21/2023] [Indexed: 09/09/2023] Open
Abstract
f-statistics have emerged as a first line of analysis for making inferences about demographic history from genome-wide data. Not only are they guaranteed to allow robust tests of the fits of proposed models of population history to data when analyzing full genome sequencing data-that is, all single nucleotide polymorphisms (SNPs) in the individuals being analyzed-but they are also guaranteed to allow robust tests of models for SNPs ascertained as polymorphic in a population that is an outgroup in a phylogenetic sense to all groups being analyzed. True "outgroup ascertainment" is in practice impossible in humans because our species has arisen from a substructured ancestral population that does not descend from a homogeneous ancestral population going back many hundreds of thousands of years into the past. However, initial studies suggested that non-outgroup-ascertainment schemes might produce robust enough results using f-statistics, and that motivated widespread fitting of models to data using non-outgroup-ascertained SNP panels such as the "Affymetrix Human Origins array" which has been genotyped on thousands of modern individuals from hundreds of populations, or the "1240k" in-solution enrichment reagent which has been the source of about 70% of published genome-wide data for ancient humans. In this study, we show that while analyses of population history using such panels work well for studies of relationships among non-African populations and one African outgroup, when co-modeling more than one sub-Saharan African and/or archaic human groups (Neanderthals and Denisovans), fitting of f-statistics to such SNP sets is expected to frequently lead to false rejection of true demographic histories, and failure to reject incorrect models. Analyzing panels of SNPs polymorphic in archaic humans, which has been suggested as a solution for the ascertainment problem, has limited statistical power and retains important biases. However, by carrying out simulations of diverse demographic histories, we show that bias in inferences based on f-statistics can be minimized by ascertaining on variants common in a union of diverse African groups; such ascertainment retains high statistical power while allowing co-analysis of archaic and modern groups.
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Affiliation(s)
- Pavel Flegontov
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
- Kalmyk Research Center of the Russian Academy of Sciences, Elista, Russia
| | - Ulaş Işıldak
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - Robert Maier
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Eren Yüncü
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - Piya Changmai
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - David Reich
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
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13
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Salehi Nowbandegani P, Wohns AW, Ballard JL, Lander ES, Bloemendal A, Neale BM, O'Connor LJ. Extremely sparse models of linkage disequilibrium in ancestrally diverse association studies. Nat Genet 2023; 55:1494-1502. [PMID: 37640881 DOI: 10.1038/s41588-023-01487-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 07/24/2023] [Indexed: 08/31/2023]
Abstract
Linkage disequilibrium (LD) is the correlation among nearby genetic variants. In genetic association studies, LD is often modeled using large correlation matrices, but this approach is inefficient, especially in ancestrally diverse studies. In the present study, we introduce LD graphical models (LDGMs), which are an extremely sparse and efficient representation of LD. LDGMs are derived from genome-wide genealogies; statistical relationships among alleles in the LDGM correspond to genealogical relationships among haplotypes. We published LDGMs and ancestry-specific LDGM precision matrices for 18 million common variants (minor allele frequency >1%) in five ancestry groups, validated their accuracy and demonstrated order-of-magnitude improvements in runtime for commonly used LD matrix computations. We implemented an extremely fast multiancestry polygenic prediction method, BLUPx-ldgm, which performs better than a similar method based on the reference LD correlation matrix. LDGMs will enable sophisticated methods that scale to ancestrally diverse genetic association data across millions of variants and individuals.
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Affiliation(s)
- Pouria Salehi Nowbandegani
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA.
| | - Anthony Wilder Wohns
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA.
- Stanford University School of Medicine, Stanford, CA, USA.
| | - Jenna L Ballard
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Graduate Group in Genomics and Computational Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Eric S Lander
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biology, MIT, Cambridge, MA, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Alex Bloemendal
- Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- The Novo Nordisk Foundation Center for Genomic Mechanisms of Disease, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Benjamin M Neale
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- The Novo Nordisk Foundation Center for Genomic Mechanisms of Disease, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Luke J O'Connor
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA.
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14
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Ragsdale AP, Thornton KR. Multiple Sources of Uncertainty Confound Inference of Historical Human Generation Times. Mol Biol Evol 2023; 40:msad160. [PMID: 37450583 PMCID: PMC10404577 DOI: 10.1093/molbev/msad160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023] Open
Abstract
Wang et al. (2023) recently proposed an approach to infer the history of human generation intervals from changes in mutation profiles over time. As the relative proportions of different mutation types depend on the ages of parents, binning variants by the time they arose allows for the inference of changes in average paternal and maternal generation intervals. Applying this approach to published allele age estimates, Wang et al. (2023) inferred long-lasting sex differences in average generation times and surprisingly found that ancestral generation times of West African populations remained substantially higher than those of Eurasian populations extending tens of thousands of generations into the past. Here, we argue that the results and interpretations in Wang et al. (2023) are primarily driven by noise and biases in input data and a lack of validation using independent approaches for estimating allele ages. With the recent development of methods to reconstruct genome-wide gene genealogies, coalescence times, and allele ages, we caution that downstream analyses may be strongly influenced by uncharacterized biases in their output.
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Affiliation(s)
- Aaron P Ragsdale
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Kevin R Thornton
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
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15
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Chevy ET, Huerta-Sánchez E, Ramachandran S. Integrating sex-bias into studies of archaic introgression on chromosome X. PLoS Genet 2023; 19:e1010399. [PMID: 37578977 PMCID: PMC10449224 DOI: 10.1371/journal.pgen.1010399] [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: 08/29/2022] [Revised: 08/24/2023] [Accepted: 07/10/2023] [Indexed: 08/16/2023] Open
Abstract
Evidence of interbreeding between archaic hominins and humans comes from methods that infer the locations of segments of archaic haplotypes, or 'archaic coverage' using the genomes of people living today. As more estimates of archaic coverage have emerged, it has become clear that most of this coverage is found on the autosomes- very little is retained on chromosome X. Here, we summarize published estimates of archaic coverage on autosomes and chromosome X from extant human samples. We find on average 7 times more archaic coverage on autosomes than chromosome X, and identify broad continental patterns in this ratio: greatest in European samples, and least in South Asian samples. We also perform extensive simulation studies to investigate how the amount of archaic coverage, lengths of coverage, and rates of purging of archaic coverage are affected by sex-bias caused by an unequal sex ratio within the archaic introgressors. Our results generally confirm that, with increasing male sex-bias, less archaic coverage is retained on chromosome X. Ours is the first study to explicitly model such sex-bias and its potential role in creating the dearth of archaic coverage on chromosome X.
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Affiliation(s)
- Elizabeth T. Chevy
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
| | - Emilia Huerta-Sánchez
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, Rhode Island, United States of America
| | - Sohini Ramachandran
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, Rhode Island, United States of America
- Data Science Initiative, Brown University, Providence, Rhode Island, United States of America
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16
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Skov L, Coll Macià M, Lucotte EA, Cavassim MIA, Castellano D, Schierup MH, Munch K. Extraordinary selection on the human X chromosome associated with archaic admixture. CELL GENOMICS 2023; 3:100274. [PMID: 36950386 PMCID: PMC10025451 DOI: 10.1016/j.xgen.2023.100274] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 09/15/2022] [Accepted: 01/26/2023] [Indexed: 03/04/2023]
Abstract
The X chromosome in non-African humans shows less diversity and less Neanderthal introgression than expected from neutral evolution. Analyzing 162 human male X chromosomes worldwide, we identified fourteen chromosomal regions where nearly identical haplotypes spanning several hundred kilobases are found at high frequencies in non-Africans. Genetic drift alone cannot explain the existence of these haplotypes, which must have been associated with strong positive selection in partial selective sweeps. Moreover, the swept haplotypes are entirely devoid of archaic ancestry as opposed to the non-swept haplotypes in the same genomic regions. The ancient Ust'-Ishim male dated at 45,000 before the present (BP) also carries the swept haplotypes, implying that selection on the haplotypes must have occurred between 45,000 and 55,000 years ago. Finally, we find that the chromosomal positions of sweeps overlap previously reported hotspots of selective sweeps in great ape evolution, suggesting a mechanism of selection unique to X chromosomes.
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Affiliation(s)
- Laurits Skov
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-5800, USA
| | - Moisès Coll Macià
- Bioinformatics Research Centre, Aarhus University, 8000 Aarhus, Denmark
| | - Elise Anne Lucotte
- Ecologie Systématique Evolution, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | | | - David Castellano
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA
| | | | - Kasper Munch
- Bioinformatics Research Centre, Aarhus University, 8000 Aarhus, Denmark
- Corresponding author
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17
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Shipilina D, Pal A, Stankowski S, Chan YF, Barton NH. On the origin and structure of haplotype blocks. Mol Ecol 2023; 32:1441-1457. [PMID: 36433653 PMCID: PMC10946714 DOI: 10.1111/mec.16793] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022]
Abstract
The term "haplotype block" is commonly used in the developing field of haplotype-based inference methods. We argue that the term should be defined based on the structure of the Ancestral Recombination Graph (ARG), which contains complete information on the ancestry of a sample. We use simulated examples to demonstrate key features of the relationship between haplotype blocks and ancestral structure, emphasizing the stochasticity of the processes that generate them. Even the simplest cases of neutrality or of a "hard" selective sweep produce a rich structure, often missed by commonly used statistics. We highlight a number of novel methods for inferring haplotype structure, based on the full ARG, or on a sequence of trees, and illustrate how they can be used to define haplotype blocks using an empirical data set. While the advent of new, computationally efficient methods makes it possible to apply these concepts broadly, they (and additional new methods) could benefit from adding features to explore haplotype blocks, as we define them. Understanding and applying the concept of the haplotype block will be essential to fully exploit long and linked-read sequencing technologies.
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Affiliation(s)
- Daria Shipilina
- Evolutionary Biology Program, Department of Ecology and Genetics (IEG), Uppsala University, Uppsala, Sweden
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- Swedish Collegium for Advanced Study, Uppsala, Sweden
| | - Arka Pal
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Sean Stankowski
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | | | - Nicholas H Barton
- Institute of Science and Technology Austria, Klosterneuburg, Austria
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18
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Flegontov P, Işıldak U, Maier R, Yüncü E, Changmai P, Reich D. Modeling of African population history using f -statistics can be highly biased and is not addressed by previously suggested SNP ascertainment schemes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.22.525077. [PMID: 36711923 PMCID: PMC9882349 DOI: 10.1101/2023.01.22.525077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
f -statistics have emerged as a first line of analysis for making inferences about demographic history from genome-wide data. These statistics can provide strong evidence for either admixture or cladality, which can be robust to substantial rates of errors or missing data. f -statistics are guaranteed to be unbiased under "SNP ascertainment" (analyzing non-randomly chosen subsets of single nucleotide polymorphisms) only if it relies on a population that is an outgroup for all groups analyzed. However, ascertainment on a true outgroup that is not co-analyzed with other populations is often impractical and uncommon in the literature. In this study focused on practical rather than theoretical aspects of SNP ascertainment, we show that many non-outgroup ascertainment schemes lead to false rejection of true demographic histories, as well as to failure to reject incorrect models. But the bias introduced by common ascertainments such as the 1240K panel is mostly limited to situations when more than one sub-Saharan African and/or archaic human groups (Neanderthals and Denisovans) or non-human outgroups are co-modelled, for example, f 4 -statistics involving one non-African group, two African groups, and one archaic group. Analyzing panels of SNPs polymorphic in archaic humans, which has been suggested as a solution for the ascertainment problem, cannot fix all these problems since for some classes of f -statistics it is not a clean outgroup ascertainment, and in other cases it demonstrates relatively low power to reject incorrect demographic models since it provides a relatively small number of variants common in anatomically modern humans. And due to the paucity of high-coverage archaic genomes, archaic individuals used for ascertainment often act as sole representatives of the respective groups in an analysis, and we show that this approach is highly problematic. By carrying out large numbers of simulations of diverse demographic histories, we find that bias in inferences based on f -statistics introduced by non-outgroup ascertainment can be minimized if the derived allele frequency spectrum in the population used for ascertainment approaches the spectrum that existed at the root of all groups being co-analyzed. Ascertaining on sites with variants common in a diverse group of African individuals provides a good approximation to such a set of SNPs, addressing the great majority of biases and also retaining high statistical power for studying population history. Such a "pan-African" ascertainment, although not completely problem-free, allows unbiased exploration of demographic models for the widest set of archaic and modern human populations, as compared to the other ascertainment schemes we explored.
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Affiliation(s)
- Pavel Flegontov
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
- Kalmyk Research Center of the Russian Academy of Sciences, Elista, Russia
| | - Ulaş Işıldak
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - Robert Maier
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Eren Yüncü
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - Piya Changmai
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - David Reich
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
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19
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Reilly PF, Tjahjadi A, Miller SL, Akey JM, Tucci S. The contribution of Neanderthal introgression to modern human traits. Curr Biol 2022; 32:R970-R983. [PMID: 36167050 PMCID: PMC9741939 DOI: 10.1016/j.cub.2022.08.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neanderthals, our closest extinct relatives, lived in western Eurasia from 400,000 years ago until they went extinct around 40,000 years ago. DNA retrieved from ancient specimens revealed that Neanderthals mated with modern human contemporaries. As a consequence, introgressed Neanderthal DNA survives scattered across the human genome such that 1-4% of the genome of present-day people outside Africa are inherited from Neanderthal ancestors. Patterns of Neanderthal introgressed genomic sequences suggest that Neanderthal alleles had distinct fates in the modern human genetic background. Some Neanderthal alleles facilitated human adaptation to new environments such as novel climate conditions, UV exposure levels and pathogens, while others had deleterious consequences. Here, we review the body of work on Neanderthal introgression over the past decade. We describe how evolutionary forces shaped the genomic landscape of Neanderthal introgression and highlight the impact of introgressed alleles on human biology and phenotypic variation.
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Affiliation(s)
| | - Audrey Tjahjadi
- Department of Anthropology, Yale University, New Haven, CT, USA
| | | | - Joshua M Akey
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
| | - Serena Tucci
- Department of Anthropology, Yale University, New Haven, CT, USA; Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA.
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20
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Recombination-aware phylogeographic inference using the structured coalescent with ancestral recombination. PLoS Comput Biol 2022; 18:e1010422. [PMID: 35984849 PMCID: PMC9447913 DOI: 10.1371/journal.pcbi.1010422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 09/06/2022] [Accepted: 07/21/2022] [Indexed: 11/19/2022] Open
Abstract
Movement of individuals between populations or demes is often restricted, especially between geographically isolated populations. The structured coalescent provides an elegant theoretical framework for describing how movement between populations shapes the genealogical history of sampled individuals and thereby structures genetic variation within and between populations. However, in the presence of recombination an individual may inherit different regions of their genome from different parents, resulting in a mosaic of genealogical histories across the genome, which can be represented by an Ancestral Recombination Graph (ARG). In this case, different genomic regions may have different ancestral histories and so different histories of movement between populations. Recombination therefore poses an additional challenge to phylogeographic methods that aim to reconstruct the movement of individuals from genealogies, although also a potential benefit in that different loci may contain additional information about movement. Here, we introduce the Structured Coalescent with Ancestral Recombination (SCAR) model, which builds on recent approximations to the structured coalescent by incorporating recombination into the ancestry of sampled individuals. The SCAR model allows us to infer how the migration history of sampled individuals varies across the genome from ARGs, and improves estimation of key population genetic parameters such as population sizes, recombination rates and migration rates. Using the SCAR model, we explore the potential and limitations of phylogeographic inference using full ARGs. We then apply the SCAR to lineages of the recombining fungus Aspergillus flavus sampled across the United States to explore patterns of recombination and migration across the genome. Phylogeographic methods are widely used to reconstruct the historical movement of individuals between different populations. When applied to infectious pathogens, these methods are often used to reconstruct the origin or source of novel pathogen lineages. Most existing phylogeographic methods reconstruct movement based on a single phylogenetic tree, which is assumed to reflect the genetic ancestry of all sampled individuals. However in populations undergoing recombination, genetic material can be exchanged between lineages such that individuals may inherit different regions of their genome from different ancestors. In this case, phylogenetic relationships among individuals can only be captured by a reticulated network rather than any single tree. Ancestral Recombination Graphs (ARGs) provide one way of capturing these reticulate relationships and we develop new models that allow for demographic inference of historical population sizes, recombination rates and migration rates between subpopulations from ARGs. By accounting for recombination, our models not only allow for accurate demographic inference, but can take full advantage of the additional information contained in ARGs about how ancestry varies across genomes to more precisely reconstruct the movement of genetic material between populations.
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21
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Peyrégne S, Kelso J, Peter BM, Pääbo S. The evolutionary history of human spindle genes includes back-and-forth gene flow with Neandertals. eLife 2022; 11:75464. [PMID: 35816093 PMCID: PMC9273211 DOI: 10.7554/elife.75464] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 06/14/2022] [Indexed: 12/13/2022] Open
Abstract
Proteins associated with the spindle apparatus, a cytoskeletal structure that ensures the proper segregation of chromosomes during cell division, experienced an unusual number of amino acid substitutions in modern humans after the split from the ancestors of Neandertals and Denisovans. Here, we analyze the history of these substitutions and show that some of the genes in which they occur may have been targets of positive selection. We also find that the two changes in the kinetochore scaffold 1 (KNL1) protein, previously believed to be specific to modern humans, were present in some Neandertals. We show that the KNL1 gene of these Neandertals shared a common ancestor with present-day Africans about 200,000 years ago due to gene flow from the ancestors (or relatives) of modern humans into Neandertals. Subsequently, some non-Africans inherited this modern human-like gene variant from Neandertals, but none inherited the ancestral gene variants. These results add to the growing evidence of early contacts between modern humans and archaic groups in Eurasia and illustrate the intricate relationships among these groups.
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Affiliation(s)
- Stéphane Peyrégne
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Janet Kelso
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Benjamin M Peter
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Svante Pääbo
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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22
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Temporal mapping of derived high-frequency gene variants supports the mosaic nature of the evolution of Homo sapiens. Sci Rep 2022; 12:9937. [PMID: 35705575 PMCID: PMC9200848 DOI: 10.1038/s41598-022-13589-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/25/2022] [Indexed: 11/25/2022] Open
Abstract
Large-scale estimations of the time of emergence of variants are essential to examine hypotheses concerning human evolution with precision. Using an open repository of genetic variant age estimations, we offer here a temporal evaluation of various evolutionarily relevant datasets, such as Homo sapiens-specific variants, high-frequency variants found in genetic windows under positive selection, introgressed variants from extinct human species, as well as putative regulatory variants specific to various brain regions. We find a recurrent bimodal distribution of high-frequency variants, but also evidence for specific enrichments of gene categories in distinct time windows, pointing to different periods of phenotypic changes, resulting in a mosaic. With a temporal classification of genetic mutations in hand, we then applied a machine learning tool to predict what genes have changed more in certain time windows, and which tissues these genes may have impacted more. Overall, we provide a fine-grained temporal mapping of derived variants in Homo sapiens that helps to illuminate the intricate evolutionary history of our species.
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23
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Abstract
The polar bear (Ursus maritimus) has become a symbol of the threat to biodiversity from climate change. Understanding polar bear evolutionary history may provide insights into apex carnivore responses and prospects during periods of extreme environmental perturbations. In recent years, genomic studies have examined bear speciation and population history, including evidence for ancient admixture between polar bears and brown bears (Ursus arctos). Here, we extend our earlier studies of a 130,000- to 115,000-y-old polar bear from the Svalbard Archipelago using a 10× coverage genome sequence and 10 new genomes of polar and brown bears from contemporary zones of overlap in northern Alaska. We demonstrate a dramatic decline in effective population size for this ancient polar bear’s lineage, followed by a modest increase just before its demise. A slightly higher genetic diversity in the ancient polar bear suggests a severe genetic erosion over a prolonged bottleneck in modern polar bears. Statistical fitting of data to alternative admixture graph scenarios favors at least one ancient introgression event from brown bears into the ancestor of polar bears, possibly dating back over 150,000 y. Gene flow was likely bidirectional, but allelic transfer from brown into polar bear is the strongest detected signal, which contrasts with other published work. These findings may have implications for our understanding of climate change impacts: Polar bears, a specialist Arctic lineage, may not only have undergone severe genetic bottlenecks but also been the recipient of generalist, boreal genetic variants from brown bears during critical phases of Northern Hemisphere glacial oscillations.
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Y. C. Brandt D, Wei X, Deng Y, Vaughn AH, Nielsen R. Evaluation of methods for estimating coalescence times using ancestral recombination graphs. Genetics 2022; 221:iyac044. [PMID: 35333304 PMCID: PMC9071567 DOI: 10.1093/genetics/iyac044] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 03/08/2022] [Indexed: 11/12/2022] Open
Abstract
The ancestral recombination graph is a structure that describes the joint genealogies of sampled DNA sequences along the genome. Recent computational methods have made impressive progress toward scalably estimating whole-genome genealogies. In addition to inferring the ancestral recombination graph, some of these methods can also provide ancestral recombination graphs sampled from a defined posterior distribution. Obtaining good samples of ancestral recombination graphs is crucial for quantifying statistical uncertainty and for estimating population genetic parameters such as effective population size, mutation rate, and allele age. Here, we use standard neutral coalescent simulations to benchmark the estimates of pairwise coalescence times from 3 popular ancestral recombination graph inference programs: ARGweaver, Relate, and tsinfer+tsdate. We compare (1) the true coalescence times to the inferred times at each locus; (2) the distribution of coalescence times across all loci to the expected exponential distribution; (3) whether the sampled coalescence times have the properties expected of a valid posterior distribution. We find that inferred coalescence times at each locus are most accurate in ARGweaver, and often more accurate in Relate than in tsinfer+tsdate. However, all 3 methods tend to overestimate small coalescence times and underestimate large ones. Lastly, the posterior distribution of ARGweaver is closer to the expected posterior distribution than Relate's, but this higher accuracy comes at a substantial trade-off in scalability. The best choice of method will depend on the number and length of input sequences and on the goal of downstream analyses, and we provide guidelines for the best practices.
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Affiliation(s)
- Débora Y. C. Brandt
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Xinzhu Wei
- Department of Computational Biology, Cornell University, Ithaca, NY 14850, USA
| | - Yun Deng
- Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Andrew H Vaughn
- Center for Computational Biology, University of California, Berkeley, CA 94720, USA
| | - Rasmus Nielsen
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Center for Computational Biology, University of California, Berkeley, CA 94720, USA
- Department of Statistics, University of California Berkeley, Berkeley, CA 94720, USA
- GLOBE Institute, University of Copenhagen, Copenhagen K 1350, Denmark
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25
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Estimating bonobo ( Pan paniscus) and chimpanzee ( Pan troglodytes) evolutionary history from nucleotide site patterns. Proc Natl Acad Sci U S A 2022; 119:e2200858119. [PMID: 35452306 PMCID: PMC9170072 DOI: 10.1073/pnas.2200858119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
There is genomic evidence of widespread admixture in deep time between many closely related species, including humans. Our closest living relatives, bonobos and chimpanzees, may also exhibit such patterns. However, assessing the exact degree of interbreeding remains challenging because previous studies have resulted in multiple inconsistent demographic models. We use an approach that addresses these gaps by analyzing all lineages, simultaneously estimating parameters, and comparing previously models. We find evidence of considerable introgression from western into eastern chimpanzees. We also show more breeding females than males and evidence of male-biased dispersal in western chimpanzees. These findings highlight the extent of admixture in bonobo and chimpanzee evolutionary history and are consistent with substantial differences between past and present chimpanzee biogeography. Admixture appears increasingly ubiquitous in the evolutionary history of various taxa, including humans. Such gene flow likely also occurred among our closest living relatives: bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). However, our understanding of their evolutionary history has been limited by studies that do not consider all Pan lineages or do not analyze all lineages simultaneously, resulting in conflicting demographic models. Here, we investigate this gap in knowledge using nucleotide site patterns calculated from whole-genome sequences from the autosomes of 71 bonobos and chimpanzees, representing all five extant Pan lineages. We estimated demographic parameters and compared all previously proposed demographic models for this clade. We further considered sex bias in Pan evolutionary history by analyzing the site patterns from the X chromosome. We show that 1) 21% of autosomal DNA in eastern chimpanzees derives from western chimpanzee introgression and that 2) all four chimpanzee lineages share a common ancestor about 987,000 y ago, much earlier than previous estimates. In addition, we suggest that 3) there was male reproductive skew throughout Pan evolutionary history and find evidence of 4) male-biased dispersal from western to eastern chimpanzees. Collectively, these results offer insight into bonobo and chimpanzee evolutionary history and suggest considerable differences between current and historic chimpanzee biogeography.
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26
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Wohns AW, Wong Y, Jeffery B, Akbari A, Mallick S, Pinhasi R, Patterson N, Reich D, Kelleher J, McVean G. A unified genealogy of modern and ancient genomes. Science 2022; 375:eabi8264. [PMID: 35201891 PMCID: PMC10027547 DOI: 10.1126/science.abi8264] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The sequencing of modern and ancient genomes from around the world has revolutionized our understanding of human history and evolution. However, the problem of how best to characterize ancestral relationships from the totality of human genomic variation remains unsolved. Here, we address this challenge with nonparametric methods that enable us to infer a unified genealogy of modern and ancient humans. This compact representation of multiple datasets explores the challenges of missing and erroneous data and uses ancient samples to constrain and date relationships. We demonstrate the power of the method to recover relationships between individuals and populations as well as to identify descendants of ancient samples. Finally, we introduce a simple nonparametric estimator of the geographical location of ancestors that recapitulates key events in human history.
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Affiliation(s)
- Anthony Wilder Wohns
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford; Oxford OX3 7LF, UK
| | - Yan Wong
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford; Oxford OX3 7LF, UK
| | - Ben Jeffery
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford; Oxford OX3 7LF, UK
| | - Ali Akbari
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Department of Human Evolutionary Biology, Harvard University; Cambridge, MA 02138, USA
- Department of Genetics, Harvard Medical School; Boston, MA 02115, USA
| | - Swapan Mallick
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Howard Hughes Medical Institute; Boston, MA 02115, USA
| | - Ron Pinhasi
- Department of Evolutionary Anthropology, University of Vienna; 1090 Vienna, Austria
| | - Nick Patterson
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Department of Human Evolutionary Biology, Harvard University; Cambridge, MA 02138, USA
- Howard Hughes Medical Institute; Boston, MA 02115, USA
- Department of Genetics, Harvard Medical School; Boston, MA 02115, USA
| | - David Reich
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Department of Human Evolutionary Biology, Harvard University; Cambridge, MA 02138, USA
- Howard Hughes Medical Institute; Boston, MA 02115, USA
- Department of Genetics, Harvard Medical School; Boston, MA 02115, USA
| | - Jerome Kelleher
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford; Oxford OX3 7LF, UK
| | - Gil McVean
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford; Oxford OX3 7LF, UK
- Corresponding author.
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27
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Slimak L, Zanolli C, Higham T, Frouin M, Schwenninger JL, Arnold LJ, Demuro M, Douka K, Mercier N, Guérin G, Valladas H, Yvorra P, Giraud Y, Seguin-Orlando A, Orlando L, Lewis JE, Muth X, Camus H, Vandevelde S, Buckley M, Mallol C, Stringer C, Metz L. Modern human incursion into Neanderthal territories 54,000 years ago at Mandrin, France. SCIENCE ADVANCES 2022; 8:eabj9496. [PMID: 35138885 PMCID: PMC8827661 DOI: 10.1126/sciadv.abj9496] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Determining the extent of overlap between modern humans and other hominins in Eurasia, such as Neanderthals and Denisovans, is fundamental to understanding the nature of their interactions and what led to the disappearance of archaic hominins. Apart from a possible sporadic pulse recorded in Greece during the Middle Pleistocene, the first settlements of modern humans in Europe have been constrained to ~45,000 to 43,000 years ago. Here, we report hominin fossils from Grotte Mandrin in France that reveal the earliest known presence of modern humans in Europe between 56,800 and 51,700 years ago. This early modern human incursion in the Rhône Valley is associated with technologies unknown in any industry of that age outside Africa or the Levant. Mandrin documents the first alternating occupation of Neanderthals and modern humans, with a modern human fossil and associated Neronian lithic industry found stratigraphically between layers containing Neanderthal remains associated with Mousterian industries.
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Affiliation(s)
- Ludovic Slimak
- CNRS, UMR 5608, TRACES, Université de Toulouse Jean Jaurès, 5 Allées Antonio Machado, 31058 Toulouse Cedex 9, France
- Corresponding author. (L.S.); (C.Z.)
| | - Clément Zanolli
- Université de Bordeaux, CNRS, MCC, PACEA, UMR 5199, 33600 Pessac, France
- Corresponding author. (L.S.); (C.Z.)
| | - Tom Higham
- Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY, UK
- Department of Evolutionary Anthropology, University of Vienna, University Biology Building, Djerassiplatz 1, A-1030 Vienna, Austria
| | - Marine Frouin
- Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY, UK
- Department of Geosciences, Stony Brook University, 255 Earth and Space Sciences Building, Stony Brook, NY 11794-2100, USA
- Turkana Basin Institute, Stony Brook University, Stony Brook, NY 11794-4364, USA
| | - Jean-Luc Schwenninger
- Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY, UK
| | - Lee J. Arnold
- School of Physical Sciences, Environment Institute, Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, North Terrace Campus, Adelaide, SA 5005, Australia
| | - Martina Demuro
- School of Physical Sciences, Environment Institute, Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, North Terrace Campus, Adelaide, SA 5005, Australia
| | - Katerina Douka
- Department of Evolutionary Anthropology, University of Vienna, University Biology Building, Djerassiplatz 1, A-1030 Vienna, Austria
- Department of Archaeology, Max Planck Institute for the Science of Human History, Kahlaische, Str. 10, 07745 Jena, Germany
| | - Norbert Mercier
- CNRS, UMR 5060, Institut de Recherche sur les Archéomatériaux and Centre de Recherche en Physique Appliquée à l’Archéologie (CRP2A), Maison de l’Archéologie, Université Bordeaux Montaigne, 33607 Pessac, France
| | - Gilles Guérin
- Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, UMR 8212 CEA CNRS UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | - Hélène Valladas
- Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, UMR 8212 CEA CNRS UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | - Pascale Yvorra
- Aix-Marseille Université, CNRS, Min. Culture, UMR 7269, LAMPEA, Maison Méditerranéenne des Sciences de l’Homme, BP 647, 5 rue du Château de l’Horloge, F-13094, Aix-en-Provence Cedex 2, France
| | - Yves Giraud
- Aix-Marseille Université, CNRS, Min. Culture, UMR 7269, LAMPEA, Maison Méditerranéenne des Sciences de l’Homme, BP 647, 5 rue du Château de l’Horloge, F-13094, Aix-en-Provence Cedex 2, France
| | | | - Ludovic Orlando
- CNRS, UMR 5288, CAGT, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Jason E. Lewis
- Turkana Basin Institute, Stony Brook University, Stony Brook, NY 11794-4364, USA
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794-4364, USA
| | | | - Hubert Camus
- PROTEE-EXPERT, 4 rue des Aspholdèles, 34750 Villeneuve-lès-Maguelone, France
| | - Ségolène Vandevelde
- Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, UMR 8212 CEA CNRS UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
- Université Paris 1–Panthéon-Sorbonne, Équipe Archéologies Environnementales, UMR 7041, ArScAn, Équipe Archéologies Environnementales, 21 allée de l’Université, 92023 Nanterre Cedex, France
| | - Mike Buckley
- Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Carolina Mallol
- Archaeological Micromorphology and Biomarkers Laboratory (AMBI Lab), Instituto Universitario de Bio-Orgánica Antonio González, Departamento de Geografía e Historia, UDI Prehistoria, Arqueología e Historia Antigua, Facultad de Geografía e Historia, Universidad de La Laguna, Tenerife, Spain
| | - Chris Stringer
- Centre for Human Evolution Research (CHER), Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK
| | - Laure Metz
- Aix-Marseille Université, CNRS, Min. Culture, UMR 7269, LAMPEA, Maison Méditerranéenne des Sciences de l’Homme, BP 647, 5 rue du Château de l’Horloge, F-13094, Aix-en-Provence Cedex 2, France
- College of Liberal Arts and Sciences, University of Connecticut, 215 Glenbrook Road, U-4098, Storrs, CT 06269-4098, USA
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28
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Simonin-Wilmer I, Orozco-del-Pino P, Bishop DT, Iles MM, Robles-Espinoza CD. An Overview of Strategies for Detecting Genotype-Phenotype Associations Across Ancestrally Diverse Populations. Front Genet 2021; 12:703901. [PMID: 34804113 PMCID: PMC8602802 DOI: 10.3389/fgene.2021.703901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 10/14/2021] [Indexed: 11/13/2022] Open
Abstract
Genome-wide association studies (GWAS) have been very successful at identifying genetic variants influencing a large number of traits. Although the great majority of these studies have been performed in European-descent individuals, it has been recognised that including populations with differing ancestries enhances the potential for identifying causal SNPs due to their differing patterns of linkage disequilibrium. However, when individuals from distinct ethnicities are included in a GWAS, it is necessary to implement a number of control steps to ensure that the identified associations are real genotype-phenotype relationships. In this Review, we discuss the analyses that are required when performing multi-ethnic studies, including methods for determining ancestry at the global and local level for sample exclusion, controlling for ancestry in association testing, and post-GWAS interrogation methods such as genomic control and meta-analysis. We hope that this overview provides a primer for those researchers interested in including distinct populations in their studies.
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Affiliation(s)
- Irving Simonin-Wilmer
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de México, Campus Juriquilla, Queretaro, Mexico
| | | | - D. Timothy Bishop
- Leeds Institute for Data Analytics and Leeds Institute of Medical Research at St. James’s, University of Leeds, Leeds, United Kingdom
| | - Mark M. Iles
- Leeds Institute for Data Analytics and Leeds Institute of Medical Research at St. James’s, University of Leeds, Leeds, United Kingdom
| | - Carla Daniela Robles-Espinoza
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de México, Campus Juriquilla, Queretaro, Mexico
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom
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29
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Li Y, Wu DD. Finding unknown species in the genomes of extant species. J Genet Genomics 2021; 48:867-871. [PMID: 34509382 DOI: 10.1016/j.jgg.2021.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/21/2021] [Accepted: 05/23/2021] [Indexed: 11/18/2022]
Abstract
Although many species have gone extinct, their genetic components might exist in extant species because of ancient hybridization. Via advances in genome sequencing and development of modern population genetics, one can find the legacy of unknown or extinct species in the context of available genomes from extant species. Such discovery can be used as a strategy to search for hidden species or fossils in conservation biology and archeology, gain novel insight into complex evolutionary history, and provide the new sources of genetic variation for breeding and trait improvement in agriculture.
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Affiliation(s)
- Yan Li
- State Key Laboratory for Conservation and Utilization of Bio-resource in Yunnan and School of Life Science & School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China.
| | - Dong-Dong Wu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
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30
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Beyer RM, Krapp M, Eriksson A, Manica A. Climatic windows for human migration out of Africa in the past 300,000 years. Nat Commun 2021; 12:4889. [PMID: 34429408 PMCID: PMC8384873 DOI: 10.1038/s41467-021-24779-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 07/02/2021] [Indexed: 11/17/2022] Open
Abstract
Whilst an African origin of modern humans is well established, the timings and routes of their expansions into Eurasia are the subject of heated debate, due to the scarcity of fossils and the lack of suitably old ancient DNA. Here, we use high-resolution palaeoclimate reconstructions to estimate how difficult it would have been for humans in terms of rainfall availability to leave the African continent in the past 300k years. We then combine these results with an anthropologically and ecologically motivated estimate of the minimum level of rainfall required by hunter-gatherers to survive, allowing us to reconstruct when, and along which geographic paths, expansions out of Africa would have been climatically feasible. The estimated timings and routes of potential contact with Eurasia are compatible with archaeological and genetic evidence of human expansions out of Africa, highlighting the key role of palaeoclimate variability for modern human dispersals.
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Affiliation(s)
- Robert M Beyer
- Department of Zoology, University of Cambridge, Cambridge, UK.
- Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, Potsdam, Germany.
| | - Mario Krapp
- Department of Zoology, University of Cambridge, Cambridge, UK
- GNS Science, Lower Hutt, New Zealand
| | - Anders Eriksson
- cGEM, cGEM, Institute of Genomics, University of Tartu, Tartu, Estonia
- Department of Medical and Molecular Genetics, King's College London, London, UK
| | - Andrea Manica
- Department of Zoology, University of Cambridge, Cambridge, UK.
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31
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Middle Pleistocene fire use: The first signal of widespread cultural diffusion in human evolution. Proc Natl Acad Sci U S A 2021; 118:2101108118. [PMID: 34301807 PMCID: PMC8346817 DOI: 10.1073/pnas.2101108118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Control of fire is one of the most important technological innovations within the evolution of humankind. The archaeological signal of fire use becomes very visible from around 400,000 y ago onward. Interestingly, this occurs at a geologically similar time over major parts of the Old World, in Africa, as well as in western Eurasia, and in different subpopulations of the wider hominin metapopulation. We interpret this spatiotemporal pattern as the result of cultural diffusion, and as representing the earliest clear-cut case of widespread cultural change resulting from diffusion in human evolution. This fire-use pattern is followed slightly later by a similar spatiotemporal distribution of Levallois technology, at the beginning of the African Middle Stone Age and the western Eurasian Middle Paleolithic. These archaeological data, as well as studies of ancient genomes, lead us to hypothesize that at the latest by 400,000 y ago, hominin subpopulations encountered one another often enough and were sufficiently tolerant toward one another to transmit ideas and techniques over large regions within relatively short time periods. Furthermore, it is likely that the large-scale social networks necessary to transmit complicated skills were also in place. Most importantly, this suggests a form of cultural behavior significantly more similar to that of extant Homo sapiens than to our great ape relatives.
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32
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Bourgeois Y, Fields P, Bento G, Ebert D. Balancing selection for pathogen resistance reveals an intercontinental signature of Red Queen coevolution. Mol Biol Evol 2021; 38:4918-4933. [PMID: 34289047 PMCID: PMC8557431 DOI: 10.1093/molbev/msab217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The link between long-term host–parasite coevolution and genetic diversity is key to understanding genetic epidemiology and the evolution of resistance. The model of Red Queen host–parasite coevolution posits that high genetic diversity is maintained when rare host resistance variants have a selective advantage, which is believed to be the mechanistic basis for the extraordinarily high levels of diversity at disease-related genes such as the major histocompatibility complex in jawed vertebrates and R-genes in plants. The parasites that drive long-term coevolution are, however, often elusive. Here we present evidence for long-term balancing selection at the phenotypic (variation in resistance) and genomic (resistance locus) level in a particular host–parasite system: the planktonic crustacean Daphnia magna and the bacterium Pasteuria ramosa. The host shows widespread polymorphisms for pathogen resistance regardless of geographic distance, even though there is a clear genome-wide pattern of isolation by distance at other sites. In the genomic region of a previously identified resistance supergene, we observed consistent molecular signals of balancing selection, including higher genetic diversity, older coalescence times, and lower differentiation between populations, which set this region apart from the rest of the genome. We propose that specific long-term coevolution by negative-frequency-dependent selection drives this elevated diversity at the host's resistance loci on an intercontinental scale and provide an example of a direct link between the host’s resistance to a virulent pathogen and the large-scale diversity of its underlying genes.
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Affiliation(s)
- Yann Bourgeois
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
| | - Peter Fields
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
| | - Gilberto Bento
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
| | - Dieter Ebert
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, 4051 Basel, Switzerland
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33
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Ahlquist KD, Bañuelos MM, Funk A, Lai J, Rong S, Villanea FA, Witt KE. Our Tangled Family Tree: New Genomic Methods Offer Insight into the Legacy of Archaic Admixture. Genome Biol Evol 2021; 13:evab115. [PMID: 34028527 PMCID: PMC8480178 DOI: 10.1093/gbe/evab115] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/07/2021] [Accepted: 05/22/2021] [Indexed: 11/30/2022] Open
Abstract
The archaic ancestry present in the human genome has captured the imagination of both scientists and the wider public in recent years. This excitement is the result of new studies pushing the envelope of what we can learn from the archaic genetic information that has survived for over 50,000 years in the human genome. Here, we review the most recent ten years of literature on the topic of archaic introgression, including the current state of knowledge on Neanderthal and Denisovan introgression, as well as introgression from other as-yet unidentified archaic populations. We focus this review on four topics: 1) a reimagining of human demographic history, including evidence for multiple admixture events between modern humans, Neanderthals, Denisovans, and other archaic populations; 2) state-of-the-art methods for detecting archaic ancestry in population-level genomic data; 3) how these novel methods can detect archaic introgression in modern African populations; and 4) the functional consequences of archaic gene variants, including how those variants were co-opted into novel function in modern human populations. The goal of this review is to provide a simple-to-access reference for the relevant methods and novel data, which has changed our understanding of the relationship between our species and its siblings. This body of literature reveals the large degree to which the genetic legacy of these extinct hominins has been integrated into the human populations of today.
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Affiliation(s)
- K D Ahlquist
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Mayra M Bañuelos
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Alyssa Funk
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Jiaying Lai
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
- Brown Center for Biomedical Informatics, Brown University, Providence, Rhode Island, USA
| | - Stephen Rong
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Fernando A Villanea
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
- Department of Anthropology, University of Colorado Boulder, Colorado, USA
| | - Kelsey E Witt
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, USA
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34
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Deng Y, Song YS, Nielsen R. The distribution of waiting distances in ancestral recombination graphs. Theor Popul Biol 2021; 141:34-43. [PMID: 34186053 DOI: 10.1016/j.tpb.2021.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 06/11/2021] [Accepted: 06/16/2021] [Indexed: 11/25/2022]
Abstract
The ancestral recombination graph (ARG) contains the full genealogical information of the sample, and many population genetic inference problems can be solved using inferred or sampled ARGs. In particular, the waiting distance between tree changes along the genome can be used to make inference about the distribution and evolution of recombination rates. To this end, we here derive an analytic expression for the distribution of waiting distances between tree changes under the sequentially Markovian coalescent model and obtain an accurate approximation to the distribution of waiting distances for topology changes. We use these results to show that some of the recently proposed methods for inferring sequences of trees along the genome provide strongly biased distributions of waiting distances. In addition, we provide a correction to an undercounting problem facing all available ARG inference methods, thereby facilitating the use of ARG inference methods to estimate temporal changes in the recombination rate.
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Affiliation(s)
- Yun Deng
- Center for Computational Biology, University of California, Berkeley, CA 94720, United States of America.
| | - Yun S Song
- Department of Statistics, University of California, Berkeley, CA 94720, United States of America; Computer Science Division, University of California, Berkeley, CA 94720, United States of America; Chan Zuckerberg Biohub, San Francisco, CA 94158, United States of America
| | - Rasmus Nielsen
- Department of Statistics, University of California, Berkeley, CA 94720, United States of America; Department of Integrative biology, University of California, Berkeley, CA 94720, United States of America.
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35
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Hershkovitz I, May H, Sarig R, Pokhojaev A, Grimaud-Hervé D, Bruner E, Fornai C, Quam R, Arsuaga JL, Krenn VA, Martinón-Torres M, de Castro JMB, Martín-Francés L, Slon V, Albessard-Ball L, Vialet A, Schüler T, Manzi G, Profico A, Di Vincenzo F, Weber GW, Zaidner Y. A Middle Pleistocene
Homo
from Nesher Ramla, Israel. Science 2021. [DOI: 10.1126/science.abh3169] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Israel Hershkovitz
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Shmunis Family Anthropology Institute, the Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hila May
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Shmunis Family Anthropology Institute, the Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rachel Sarig
- The Shmunis Family Anthropology Institute, the Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Oral Biology, the Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ariel Pokhojaev
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Shmunis Family Anthropology Institute, the Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Oral Biology, the Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dominique Grimaud-Hervé
- UMR7194, HNHP, Département Homme et Environnement, Muséum national d’Histoire naturelle, CNRS, UPVD, Paris, France
| | - Emiliano Bruner
- CENIEH (National Research Center on Human Evolution), Burgos, Spain
| | - Cinzia Fornai
- Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Rolf Quam
- Department of Anthropology, Binghamton University (SUNY), Binghamton, NY, USA
- Centro UCM-ISCIII de Evolución y Comportamiento Humanos, Madrid, Spain
- Division of Anthropology, American Museum of Natural History, New York, NY, USA
| | - Juan Luis Arsuaga
- Centro UCM-ISCIII de Evolución y Comportamiento Humanos, Madrid, Spain
- Departamento de Geodináica, Estratigrafía y Paleontología, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Viktoria A. Krenn
- Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Maria Martinón-Torres
- CENIEH (National Research Center on Human Evolution), Burgos, Spain
- Department of Anthropology, University College London, London, UK
| | - José María Bermúdez de Castro
- CENIEH (National Research Center on Human Evolution), Burgos, Spain
- Department of Anthropology, University College London, London, UK
| | - Laura Martín-Francés
- CENIEH (National Research Center on Human Evolution), Burgos, Spain
- Department of Anthropology, University College London, London, UK
| | - Viviane Slon
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Shmunis Family Anthropology Institute, the Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lou Albessard-Ball
- UMR7194, HNHP, Département Homme et Environnement, Muséum national d’Histoire naturelle, CNRS, UPVD, Paris, France
- PalaeoHub, Department of Archaeology, University of York, York, UK
| | - Amélie Vialet
- UMR7194, HNHP, Département Homme et Environnement, Muséum national d’Histoire naturelle, CNRS, UPVD, Paris, France
| | - Tim Schüler
- Thuringian State Office for the Preservation of Historical Monuments and Archaeology Weimar, Germany
| | - Giorgio Manzi
- Department of Environmental Biology, Sapienza University of Rome, Roma, Italy
| | - Antonio Profico
- PalaeoHub, Department of Archaeology, University of York, York, UK
- Department of Environmental Biology, Sapienza University of Rome, Roma, Italy
| | - Fabio Di Vincenzo
- Department of Environmental Biology, Sapienza University of Rome, Roma, Italy
| | - Gerhard W. Weber
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
- Core Facility for Micro-Computed Tomography, University of Vienna, Vienna, Austria
| | - Yossi Zaidner
- Institute of Archaeology, The Hebrew University of Jerusalem, Jerusalem, Israel
- Zinman Institute of Archaeology, University of Haifa, Haifa, Mount Carmel, Israel
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36
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Gower G, Picazo PI, Fumagalli M, Racimo F. Detecting adaptive introgression in human evolution using convolutional neural networks. eLife 2021; 10:64669. [PMID: 34032215 PMCID: PMC8192126 DOI: 10.7554/elife.64669] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 05/24/2021] [Indexed: 01/10/2023] Open
Abstract
Studies in a variety of species have shown evidence for positively selected variants introduced into a population via introgression from another, distantly related population—a process known as adaptive introgression. However, there are few explicit frameworks for jointly modelling introgression and positive selection, in order to detect these variants using genomic sequence data. Here, we develop an approach based on convolutional neural networks (CNNs). CNNs do not require the specification of an analytical model of allele frequency dynamics and have outperformed alternative methods for classification and parameter estimation tasks in various areas of population genetics. Thus, they are potentially well suited to the identification of adaptive introgression. Using simulations, we trained CNNs on genotype matrices derived from genomes sampled from the donor population, the recipient population and a related non-introgressed population, in order to distinguish regions of the genome evolving under adaptive introgression from those evolving neutrally or experiencing selective sweeps. Our CNN architecture exhibits 95% accuracy on simulated data, even when the genomes are unphased, and accuracy decreases only moderately in the presence of heterosis. As a proof of concept, we applied our trained CNNs to human genomic datasets—both phased and unphased—to detect candidates for adaptive introgression that shaped our evolutionary history.
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Affiliation(s)
- Graham Gower
- Lundbeck GeoGenetics Centre, Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pablo Iáñez Picazo
- Lundbeck GeoGenetics Centre, Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matteo Fumagalli
- Department of Life Sciences, Silwood Park Campus, Imperial College London, London, United Kingdom
| | - Fernando Racimo
- Lundbeck GeoGenetics Centre, Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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37
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Bourgeois YXC, Warren BH. An overview of current population genomics methods for the analysis of whole-genome resequencing data in eukaryotes. Mol Ecol 2021; 30:6036-6071. [PMID: 34009688 DOI: 10.1111/mec.15989] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/26/2021] [Accepted: 05/11/2021] [Indexed: 01/01/2023]
Abstract
Characterizing the population history of a species and identifying loci underlying local adaptation is crucial in functional ecology, evolutionary biology, conservation and agronomy. The constant improvement of high-throughput sequencing techniques has facilitated the production of whole genome data in a wide range of species. Population genomics now provides tools to better integrate selection into a historical framework, and take into account selection when reconstructing demographic history. However, this improvement has come with a profusion of analytical tools that can confuse and discourage users. Such confusion limits the amount of information effectively retrieved from complex genomic data sets, and impairs the diffusion of the most recent analytical tools into fields such as conservation biology. It may also lead to redundancy among methods. To address these isssues, we propose an overview of more than 100 state-of-the-art methods that can deal with whole genome data. We summarize the strategies they use to infer demographic history and selection, and discuss some of their limitations. A website listing these methods is available at www.methodspopgen.com.
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Affiliation(s)
| | - Ben H Warren
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, UA, CP 51, Paris, France
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38
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Widespread Denisovan ancestry in Island Southeast Asia but no evidence of substantial super-archaic hominin admixture. Nat Ecol Evol 2021; 5:616-624. [PMID: 33753899 DOI: 10.1038/s41559-021-01408-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 02/03/2021] [Indexed: 01/31/2023]
Abstract
The hominin fossil record of Island Southeast Asia (ISEA) indicates that at least two endemic 'super-archaic' species-Homo luzonensis and H. floresiensis-were present around the time anatomically modern humans arrived in the region >50,000 years ago. Intriguingly, contemporary human populations across ISEA carry distinct genomic traces of ancient interbreeding events with Denisovans-a separate hominin lineage that currently lacks a fossil record in ISEA. To query this apparent disparity between fossil and genetic evidence, we performed a comprehensive search for super-archaic introgression in >400 modern human genomes, including >200 from ISEA. Our results corroborate widespread Denisovan ancestry in ISEA populations, but fail to detect any substantial super-archaic admixture signals compatible with the endemic fossil record of ISEA. We discuss the implications of our findings for the understanding of hominin history in ISEA, including future research directions that might help to unlock more details about the prehistory of the enigmatic Denisovans.
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39
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Schwartz JH. Evolution, systematics, and the unnatural history of mitochondrial DNA. Mitochondrial DNA A DNA Mapp Seq Anal 2021; 32:126-151. [PMID: 33818247 DOI: 10.1080/24701394.2021.1899165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The tenets underlying the use of mtDNA in phylogenetic and systematic analyses are strict maternal inheritance, clonality, homoplasmy, and difference due to mutation: that is, there are species-specific mtDNA sequences and phylogenetic reconstruction is a matter of comparing these sequences and inferring closeness of relatedness from the degree of sequence similarity. Yet, how mtDNA behavior became so defined is mysterious. Even though early studies of fertilization demonstrated for most animals that not only the head, but the sperm's tail and mitochondria-bearing midpiece penetrate the egg, the opposite - only the head enters the egg - became fact, and mtDNA conceived as maternally transmitted. When midpiece/tail penetration was realized as true, the conceptions 'strict maternal inheritance', etc., and their application to evolutionary endeavors, did not change. Yet there is mounting evidence of paternal mtDNA transmission, paternal and maternal combination, intracellular recombination, and intra- and intercellular heteroplasmy. Clearly, these phenomena impact the systematic and phylogenetic analysis of mtDNA sequences.
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Affiliation(s)
- Jeffrey H Schwartz
- Department of Anthropology, University of Pittsburgh, Pittsburgh, PA, USA
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40
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Abstract
Throughout human history, large-scale migrations have facilitated the formation of populations with ancestry from multiple previously separated populations. This process leads to subsequent shuffling of genetic ancestry through recombination, producing variation in ancestry between populations, among individuals in a population, and along the genome within an individual. Recent methodological and empirical developments have elucidated the genomic signatures of this admixture process, bringing previously understudied admixed populations to the forefront of population and medical genetics. Under this theme, we present a collection of recent PLOS Genetics publications that exemplify recent progress in human genetic admixture studies, and we discuss potential areas for future work.
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Affiliation(s)
- Katharine L. Korunes
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, United States of America
| | - Amy Goldberg
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, United States of America
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41
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Bergström A, Stringer C, Hajdinjak M, Scerri EML, Skoglund P. Origins of modern human ancestry. Nature 2021; 590:229-237. [PMID: 33568824 DOI: 10.1038/s41586-021-03244-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/14/2020] [Indexed: 01/30/2023]
Abstract
New finds in the palaeoanthropological and genomic records have changed our view of the origins of modern human ancestry. Here we review our current understanding of how the ancestry of modern humans around the globe can be traced into the deep past, and which ancestors it passes through during our journey back in time. We identify three key phases that are surrounded by major questions, and which will be at the frontiers of future research. The most recent phase comprises the worldwide expansion of modern humans between 40 and 60 thousand years ago (ka) and their last known contacts with archaic groups such as Neanderthals and Denisovans. The second phase is associated with a broadly construed African origin of modern human diversity between 60 and 300 ka. The oldest phase comprises the complex separation of modern human ancestors from archaic human groups from 0.3 to 1 million years ago. We argue that no specific point in time can currently be identified at which modern human ancestry was confined to a limited birthplace, and that patterns of the first appearance of anatomical or behavioural traits that are used to define Homo sapiens are consistent with a range of evolutionary histories.
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Affiliation(s)
- Anders Bergström
- Ancient Genomics Laboratory, Francis Crick Institute, London, UK
| | - Chris Stringer
- Department of Earth Sciences, Natural History Museum, London, UK.
| | - Mateja Hajdinjak
- Ancient Genomics Laboratory, Francis Crick Institute, London, UK
| | - Eleanor M L Scerri
- Pan-African Evolution Research Group, Max Planck Institute for Science of Human History, Jena, Germany.,Department of Classics and Archaeology, University of Malta, Msida, Malta.,Institute of Prehistoric Archaeology, University of Cologne, Cologne, Germany
| | - Pontus Skoglund
- Ancient Genomics Laboratory, Francis Crick Institute, London, UK.
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42
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Árnason Ú, Hallström B. The reversal of human phylogeny: Homo left Africa as erectus, came back as sapiens sapiens. Hereditas 2020; 157:51. [PMID: 33341120 PMCID: PMC7749984 DOI: 10.1186/s41065-020-00163-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 11/27/2020] [Indexed: 11/25/2022] Open
Abstract
Background The molecular out of Africa hypothesis, OOAH, has been considered as an established fact amid population geneticists for some 25–30 years despite the early concern with it among phylogeneticists with experience beyond that of Homo. The palaeontological support for the hypothesis is also questionable, a circumstance that in the light of expanding Eurasian palaeontological knowledge has become accentuated through the last decades. Results The direction of evolution in the phylogenetic tree of modern humans (Homo sapiens sapiens, Hss) was established inter alia by applying progressive phylogenetic analysis to an mtDNA sampling that included a Eurasian, Lund, and the African Mbuti, San and Yoruba. The examination identified the African populations as paraphyletic, thereby compromising the OOAH. The finding, which was consistent with the out of Eurasia hypothesis, OOEH, was corroborated by the mtDNA introgression from Hss into Hsnn (Neanderthals) that demonstrated the temporal and physical Eurasian coexistence of the two lineages. The results are consistent with the palaeontologically established presence of H. erectus in Eurasia, a Eurasian divergence between H. sapiens and H. antecessor ≈ 850,000 YBP, an Hs divergence between Hss and Hsn (Neanderthals + Denisovans) ≈ 800,000 YBP, an mtDNA introgression from Hss into Hsnn* ≈ 500,000 YBP and an Eurasian divergence among the ancestors of extant Hss ≈ 250,000 YBP at the exodus of Mbuti/San into Africa. Conclusions The present study showed that Eurasia was not the receiver but the donor in Hss evolution. The findings that Homo left Africa as erectus and returned as sapiens sapiens constitute a change in the understanding of Hs evolution to one that conforms to the extensive Eurasian record of Hs palaeontology and archaeology.
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Affiliation(s)
- Úlfur Árnason
- Department of Brain Surgery, Faculty of Medicine, University of Lund, Lund, Sweden.
| | - Björn Hallström
- Center for Translational Genomics, Faculty of Medicine, University of Lund, Lund, Sweden
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43
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Petr M, Hajdinjak M, Fu Q, Essel E, Rougier H, Crevecoeur I, Semal P, Golovanova LV, Doronichev VB, Lalueza-Fox C, de la Rasilla M, Rosas A, Shunkov MV, Kozlikin MB, Derevianko AP, Vernot B, Meyer M, Kelso J. The evolutionary history of Neanderthal and Denisovan Y chromosomes. Science 2020; 369:1653-1656. [PMID: 32973032 DOI: 10.1126/science.abb6460] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/06/2020] [Indexed: 12/31/2022]
Abstract
Ancient DNA has provided new insights into many aspects of human history. However, we lack comprehensive studies of the Y chromosomes of Denisovans and Neanderthals because the majority of specimens that have been sequenced to sufficient coverage are female. Sequencing Y chromosomes from two Denisovans and three Neanderthals shows that the Y chromosomes of Denisovans split around 700 thousand years ago from a lineage shared by Neanderthals and modern human Y chromosomes, which diverged from each other around 370 thousand years ago. The phylogenetic relationships of archaic and modern human Y chromosomes differ from the population relationships inferred from the autosomal genomes and mirror mitochondrial DNA phylogenies, indicating replacement of both the mitochondrial and Y chromosomal gene pools in late Neanderthals. This replacement is plausible if the low effective population size of Neanderthals resulted in an increased genetic load in Neanderthals relative to modern humans.
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Affiliation(s)
- Martin Petr
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany.
| | - Mateja Hajdinjak
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany.,The Francis Crick Institute, NW1 1AT London, UK
| | - Qiaomei Fu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, IVPP, CAS, Beijing 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Elena Essel
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany
| | - Hélène Rougier
- Department of Anthropology, California State University, Northridge, Northridge, CA 91330-8244, USA
| | | | - Patrick Semal
- Royal Belgian Institute of Natural Sciences, 1000 Brussels, Belgium
| | | | | | - Carles Lalueza-Fox
- Institute of Evolutionary Biology, Consejo Superior de Investigaciones Científicas, Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Marco de la Rasilla
- Área de Prehistoria, Departamento de Historia, Universidad de Oviedo, 33011 Oviedo, Spain
| | - Antonio Rosas
- Departamento de Paleobiología, Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
| | - Michael V Shunkov
- Institute of Archaeology and Ethnography, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Maxim B Kozlikin
- Institute of Archaeology and Ethnography, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Anatoli P Derevianko
- Institute of Archaeology and Ethnography, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Benjamin Vernot
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany
| | - Matthias Meyer
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany
| | - Janet Kelso
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany.
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44
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Genomic islands of differentiation in a rapid avian radiation have been driven by recent selective sweeps. Proc Natl Acad Sci U S A 2020; 117:30554-30565. [PMID: 33199636 DOI: 10.1073/pnas.2015987117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Numerous studies of emerging species have identified genomic "islands" of elevated differentiation against a background of relative homogeneity. The causes of these islands remain unclear, however, with some signs pointing toward "speciation genes" that locally restrict gene flow and others suggesting selective sweeps that have occurred within nascent species after speciation. Here, we examine this question through the lens of genome sequence data for five species of southern capuchino seedeaters, finch-like birds from South America that have undergone a species radiation during the last ∼50,000 generations. By applying newly developed statistical methods for ancestral recombination graph inference and machine-learning methods for the prediction of selective sweeps, we show that previously identified islands of differentiation in these birds appear to be generally associated with relatively recent, species-specific selective sweeps, most of which are predicted to be soft sweeps acting on standing genetic variation. Many of these sweeps coincide with genes associated with melanin-based variation in plumage, suggesting a prominent role for sexual selection. At the same time, a few loci also exhibit indications of possible selection against gene flow. These observations shed light on the complex manner in which natural selection shapes genome sequences during speciation.
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45
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Fasciola Species Introgression: Just a Fluke or Something More? Trends Parasitol 2020; 37:25-34. [PMID: 33097425 PMCID: PMC7575431 DOI: 10.1016/j.pt.2020.09.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/11/2020] [Accepted: 09/15/2020] [Indexed: 12/25/2022]
Abstract
The threats posed by a range of viral and bacterial zoonotic diseases inevitably receive renewed attention in the wake of global pandemic events due to their overt and devastating impacts on human health and the economy. Parasitic zoonoses, however, many of which affect millions of people each day, are frequently ignored. In the case of fasciolosis, caused by infection with Fasciola hepatica or Fasciola gigantica, this oversight has allowed for the expansion of areas of parasite sympatry and thus increased the incidence of hybridization and possible introgression between the two species. Here we highlight how an increased demand for animal-derived protein, combined with a lack of appropriate tools for detection of these events, is changing the status quo of these zoonotic parasites. Increased demand for animal-derived protein from Fasciola hepatica-endemic countries has led to a growing number of reports of hybridization between F. hepatica and Fasciola gigantica in Southeast Asia. Hybridization and eventual introgression have been reported in a range of protozoan, helminth, and arthropod parasites and act as important drivers of evolutionary change and adaptation. Introgression between Fasciola spp. remains unproven but has potentially serious human and animal health consequences as seen in other parasites. New tools for the characterization of hybridization and introgression events between Fasciola spp. are needed.
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46
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47
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Mughal MR, Koch H, Huang J, Chiaromonte F, DeGiorgio M. Learning the properties of adaptive regions with functional data analysis. PLoS Genet 2020; 16:e1008896. [PMID: 32853200 PMCID: PMC7480868 DOI: 10.1371/journal.pgen.1008896] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 09/09/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
Identifying regions of positive selection in genomic data remains a challenge in population genetics. Most current approaches rely on comparing values of summary statistics calculated in windows. We present an approach termed SURFDAWave, which translates measures of genetic diversity calculated in genomic windows to functional data. By transforming our discrete data points to be outputs of continuous functions defined over genomic space, we are able to learn the features of these functions that signify selection. This enables us to confidently identify complex modes of natural selection, including adaptive introgression. We are also able to predict important selection parameters that are responsible for shaping the inferred selection events. By applying our model to human population-genomic data, we recapitulate previously identified regions of selective sweeps, such as OCA2 in Europeans, and predict that its beneficial mutation reached a frequency of 0.02 before it swept 1,802 generations ago, a time when humans were relatively new to Europe. In addition, we identify BNC2 in Europeans as a target of adaptive introgression, and predict that it harbors a beneficial mutation that arose in an archaic human population that split from modern humans within the hypothesized modern human-Neanderthal divergence range.
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Affiliation(s)
- Mehreen R. Mughal
- Bioinformatics and Genomics at the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Hillary Koch
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Jinguo Huang
- Bioinformatics and Genomics at the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Francesca Chiaromonte
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Michael DeGiorgio
- Department of Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, Florida, United States of America
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