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Jackson TK, Rhode C. Comparative genomics of dusky kob (Argyrosomus japonicus, Sciaenidae) conspecifics: Evidence for speciation and the genetic mechanisms underlying traits. JOURNAL OF FISH BIOLOGY 2024. [PMID: 38885946 DOI: 10.1111/jfb.15844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 04/17/2024] [Accepted: 05/28/2024] [Indexed: 06/20/2024]
Abstract
Dusky kob (Argyrosomus japonicus) is a commercially important finfish, indigenous to South Africa, Australia, and China. Previous studies highlighted differences in genetic composition, life history, and morphology of the species across geographic regions. A draft genome sequence of 0.742 Gb (N50 = 5.49 Mb; BUSCO completeness = 97.8%) and 22,438 predicted protein-coding genes was generated for the South African (SA) conspecific. A comparison with the Chinese (CN) conspecific revealed a core set of 32,068 orthologous protein clusters across both genomes. The SA genome exhibited 440 unique clusters compared to 1928 unique clusters in the CN genome. Transportation and immune response processes were overrepresented among the SA accessory genome, whereas the CN accessory genome was enriched for immune response, DNA transposition, and sensory detection (FDR-adjusted p < 0.01). These unique clusters may represent an adaptive component of the species' pangenome that could explain population divergence due to differential environmental specialisation. Furthermore, 700 single-copy orthologues (SCOs) displayed evidence of positive selection between the SA and CN genomes, and globally these genomes shared only 92% similarity, suggesting they might be distinct species. These genes primarily play roles in metabolism and digestion, illustrating the evolutionary pathways that differentiate the species. Understanding these genomic mechanisms underlying adaptation and evolution within and between species provides valuable insights into growth and maturation of kob, traits that are particularly relevant to commercial aquaculture.
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Affiliation(s)
- Tassin Kim Jackson
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
| | - Clint Rhode
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
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2
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Wei R, Chang YW, Xie HF, Wu CD, Yuan DR, Gong WR, Du YZ. Population genetic structure of Pomacea canaliculata in China based on the COI and ITS1 genes. Sci Rep 2024; 14:12045. [PMID: 38802502 PMCID: PMC11130151 DOI: 10.1038/s41598-024-62554-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 05/18/2024] [Indexed: 05/29/2024] Open
Abstract
Comprehending the phylogeography of invasive organisms enhances our insight into their distribution dynamics, which is instrumental for the development of effective prevention and management strategies. In China, Pomacea canaliculata and Pomacea maculata are the two most widespread and damaging species of the non-native Pomacea spp.. Given this species' rapid spread throughout country, it is urgent to investigate the genetic diversity and structure of its different geographic populations, a task undertaken in the current study using the COI and ITS1 mitochondrial and ribosomal DNA genes, respectively. The result of this study, based on a nationwide systematic survey, a collection of Pomacea spp., and the identification of cryptic species, showed that there is a degree of genetic diversity and differentiation in P. canaliculata, and that all of its variations are mainly due to differences between individuals within different geographical populations. Indeed, this species contains multiple haplotypes, but none of them form a systematic geographical population structure. Furthermore, the COI gene exhibits higher genetic diversity than the ITS1 gene. Our study further clarifies the invasive pathways and dispersal patterns of P. canaliculata in China to provide a theoretical basis.
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Affiliation(s)
- Ran Wei
- College of Plant Protection, Yangzhou University, Yangzhou, 225009, China
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, China
| | - Ya-Wen Chang
- College of Plant Protection, Yangzhou University, Yangzhou, 225009, China
| | - Hong-Fang Xie
- Plant Protection and Quarantine Station of Nanjing City, Nanjing, 210029, Jiangsu Province, China
| | - Cheng-Dong Wu
- Pukou Agricultural Technology Extension Center of Nanjing City, Nanjing, 211800, China
| | - Deng-Rong Yuan
- Plant Protection and Quarantine Station of Nanjing City, Nanjing, 210029, Jiangsu Province, China
| | - Wei-Rong Gong
- Plant Protection and Quarantine Station of Jiangsu Province, Nanjing, 210036, China
| | - Yu-Zhou Du
- College of Plant Protection, Yangzhou University, Yangzhou, 225009, China.
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3
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Weibel CA, Wheeler AL, James JE, Willis SM, McShea H, Masel J. The protein domains of vertebrate species in which selection is more effective have greater intrinsic structural disorder. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.02.530449. [PMID: 38712167 PMCID: PMC11071303 DOI: 10.1101/2023.03.02.530449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The nearly neutral theory of molecular evolution posits variation among species in the effectiveness of selection. In an idealized model, the census population size determines both this minimum magnitude of the selection coefficient required for deleterious variants to be reliably purged, and the amount of neutral diversity. Empirically, an "effective population size" is often estimated from the amount of putatively neutral genetic diversity and is assumed to also capture a species' effectiveness of selection. A potentially more direct measure of the effectiveness of selection is the degree to which selection maintains preferred codons. However, past metrics that compare codon bias across species are confounded by among-species variation in %GC content and/or amino acid composition. Here we propose a new Codon Adaptation Index of Species (CAIS), based on Kullback-Leibler divergence, that corrects for both confounders. We demonstrate the use of CAIS correlations, as well as the Effective Number of Codons, to show that the protein domains of more highly adapted vertebrate species evolve higher intrinsic structural disorder.
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Affiliation(s)
- Catherine A. Weibel
- Department of Mathematics, University of Arizona, Tucson, Arizona 85721, USA
- Department of Physics, University of Arizona, Tucson, Arizona 85721, USA
- present address: Department of Applied Physics, Stanford University, California, USA
| | - Andrew L. Wheeler
- Genetics Graduate Interdisciplinary Program, University of Arizona, Tucson, Arizona 85721, USA
| | - Jennifer E. James
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
- present address: Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Sweden
| | - Sara M. Willis
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
- present address: University Information Technology Services, University of Arizona, Tucson, Arizona 85721, USA
| | - Hanon McShea
- Department of Earth System Science, Stanford University
| | - Joanna Masel
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
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4
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Zhang T, Peng W, Xiao H, Cao S, Chen Z, Su X, Luo Y, Liu Z, Peng Y, Yang X, Jiang GF, Xu X, Ma Z, Zhou Y. Population genomics highlights structural variations in local adaptation to saline coastal environments in woolly grape. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024. [PMID: 38578160 DOI: 10.1111/jipb.13653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 03/04/2024] [Indexed: 04/06/2024]
Abstract
Structural variations (SVs) are a feature of plant genomes that has been largely unexplored despite their significant impact on plant phenotypic traits and local adaptation to abiotic and biotic stress. In this study, we employed woolly grape (Vitis retordii), a species native to the tropical and subtropical regions of East Asia with both coastal and inland habitats, as a valuable model for examining the impact of SVs on local adaptation. We assembled a haplotype-resolved chromosomal reference genome for woolly grape, and conducted population genetic analyses based on whole-genome sequencing (WGS) data from coastal and inland populations. The demographic analyses revealed recent bottlenecks in all populations and asymmetric gene flow from the inland to the coastal population. In total, 1,035 genes associated with plant adaptive regulation for salt stress, radiation, and environmental adaptation were detected underlying local selection by SVs and SNPs in the coastal population, of which 37.29% and 65.26% were detected by SVs and SNPs, respectively. Candidate genes such as FSD2, RGA1, and AAP8 associated with salt tolerance were found to be highly differentiated and selected during the process of local adaptation to coastal habitats in SV regions. Our study highlights the importance of SVs in local adaptation; candidate genes related to salt stress and climatic adaptation to tropical and subtropical environments are important genomic resources for future breeding programs of grapevine and its rootstocks.
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Affiliation(s)
- Tianhao Zhang
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning, 530004, China
- College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenjing Peng
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China
- Guangxi Key Laboratory of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning, 530004, China
| | - Hua Xiao
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Shuo Cao
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
- Key Laboratory of Horticultural Plant Biology Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhuyifu Chen
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Xiangnian Su
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning, 530004, China
| | - Yuanyuan Luo
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009, China
| | - Zhongjie Liu
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Yanling Peng
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Xiping Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China
- Guangxi Key Laboratory of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning, 530004, China
| | - Guo-Feng Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning, 530004, China
| | - Xiaodong Xu
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Zhiyao Ma
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Yongfeng Zhou
- National Key Laboratory of Tropical Crop Breeding, Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
- National Key Laboratory of Tropical Crop Breeding, Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
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5
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Rodrigues MF, Kern AD, Ralph PL. Shared evolutionary processes shape landscapes of genomic variation in the great apes. Genetics 2024; 226:iyae006. [PMID: 38242701 PMCID: PMC10990428 DOI: 10.1093/genetics/iyae006] [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: 10/26/2023] [Revised: 10/26/2023] [Accepted: 01/03/2024] [Indexed: 01/21/2024] Open
Abstract
For at least the past 5 decades, population genetics, as a field, has worked to describe the precise balance of forces that shape patterns of variation in genomes. The problem is challenging because modeling the interactions between evolutionary processes is difficult, and different processes can impact genetic variation in similar ways. In this paper, we describe how diversity and divergence between closely related species change with time, using correlations between landscapes of genetic variation as a tool to understand the interplay between evolutionary processes. We find strong correlations between landscapes of diversity and divergence in a well-sampled set of great ape genomes, and explore how various processes such as incomplete lineage sorting, mutation rate variation, GC-biased gene conversion and selection contribute to these correlations. Through highly realistic, chromosome-scale, forward-in-time simulations, we show that the landscapes of diversity and divergence in the great apes are too well correlated to be explained via strictly neutral processes alone. Our best fitting simulation includes both deleterious and beneficial mutations in functional portions of the genome, in which 9% of fixations within those regions is driven by positive selection. This study provides a framework for modeling genetic variation in closely related species, an approach which can shed light on the complex balance of forces that have shaped genetic variation.
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Affiliation(s)
- Murillo F Rodrigues
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, USA
- Department of Biology, University of Oregon, Eugene, OR 97403, USA
| | - Andrew D Kern
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, USA
- Department of Biology, University of Oregon, Eugene, OR 97403, USA
| | - Peter L Ralph
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, USA
- Department of Biology, University of Oregon, Eugene, OR 97403, USA
- Department of Mathematics, University of Oregon, Eugene, OR 97403, USA
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6
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Murga-Moreno J, Casillas S, Barbadilla A, Uricchio L, Enard D. An efficient and robust ABC approach to infer the rate and strength of adaptation. G3 (BETHESDA, MD.) 2024; 14:jkae031. [PMID: 38365205 PMCID: PMC11090462 DOI: 10.1093/g3journal/jkae031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 10/10/2023] [Accepted: 01/29/2024] [Indexed: 02/18/2024]
Abstract
Inferring the effects of positive selection on genomes remains a critical step in characterizing the ultimate and proximate causes of adaptation across species, and quantifying positive selection remains a challenge due to the confounding effects of many other evolutionary processes. Robust and efficient approaches for adaptation inference could help characterize the rate and strength of adaptation in nonmodel species for which demographic history, mutational processes, and recombination patterns are not currently well-described. Here, we introduce an efficient and user-friendly extension of the McDonald-Kreitman test (ABC-MK) for quantifying long-term protein adaptation in specific lineages of interest. We characterize the performance of our approach with forward simulations and find that it is robust to many demographic perturbations and positive selection configurations, demonstrating its suitability for applications to nonmodel genomes. We apply ABC-MK to the human proteome and a set of known virus interacting proteins (VIPs) to test the long-term adaptation in genes interacting with viruses. We find substantially stronger signatures of positive selection on RNA-VIPs than DNA-VIPs, suggesting that RNA viruses may be an important driver of human adaptation over deep evolutionary time scales.
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Affiliation(s)
- Jesús Murga-Moreno
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85719, USA
| | - Sònia Casillas
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Antonio Barbadilla
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | | | - David Enard
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85719, USA
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7
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Matheson J, Masel J. Background Selection From Unlinked Sites Causes Nonindependent Evolution of Deleterious Mutations. Genome Biol Evol 2024; 16:evae050. [PMID: 38482769 PMCID: PMC10972689 DOI: 10.1093/gbe/evae050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2024] [Indexed: 04/01/2024] Open
Abstract
Background selection describes the reduction in neutral diversity caused by selection against deleterious alleles at other loci. It is typically assumed that the purging of deleterious alleles affects linked neutral variants, and indeed simulations typically only treat a genomic window. However, background selection at unlinked loci also depresses neutral diversity. In agreement with previous analytical approximations, in our simulations of a human-like genome with a realistically high genome-wide deleterious mutation rate, the effects of unlinked background selection exceed those of linked background selection. Background selection reduces neutral genetic diversity by a factor that is independent of census population size. Outside of genic regions, the strength of background selection increases with the mean selection coefficient, contradicting the linked theory but in agreement with the unlinked theory. Neutral diversity within genic regions is fairly independent of the strength of selection. Deleterious genetic load among haploid individuals is underdispersed, indicating nonindependent evolution of deleterious mutations. Empirical evidence for underdispersion was previously interpreted as evidence for global epistasis, but we recover it from a non-epistatic model.
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Affiliation(s)
- Joseph Matheson
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
- Department of Ecology, Behavior, and Evolution, University of California San Diego, San Diego, CA 92093, USA
| | - Joanna Masel
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
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8
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Simon A, Coop G. The contribution of gene flow, selection, and genetic drift to five thousand years of human allele frequency change. Proc Natl Acad Sci U S A 2024; 121:e2312377121. [PMID: 38363870 PMCID: PMC10907250 DOI: 10.1073/pnas.2312377121] [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: 07/19/2023] [Accepted: 01/09/2024] [Indexed: 02/18/2024] Open
Abstract
Genomic time series from experimental evolution studies and ancient DNA datasets offer us a chance to directly observe the interplay of various evolutionary forces. We show how the genome-wide variance in allele frequency change between two time points can be decomposed into the contributions of gene flow, genetic drift, and linked selection. In closed populations, the contribution of linked selection is identifiable because it creates covariances between time intervals, and genetic drift does not. However, repeated gene flow between populations can also produce directionality in allele frequency change, creating covariances. We show how to accurately separate the fraction of variance in allele frequency change due to admixture and linked selection in a population receiving gene flow. We use two human ancient DNA datasets, spanning around 5,000 y, as time transects to quantify the contributions to the genome-wide variance in allele frequency change. We find that a large fraction of genome-wide change is due to gene flow. In both cases, after correcting for known major gene flow events, we do not observe a signal of genome-wide linked selection. Thus despite the known role of selection in shaping long-term polymorphism levels, and an increasing number of examples of strong selection on single loci and polygenic scores from ancient DNA, it appears to be gene flow and drift, and not selection, that are the main determinants of recent genome-wide allele frequency change. Our approach should be applicable to the growing number of contemporary and ancient temporal population genomics datasets.
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Affiliation(s)
- Alexis Simon
- Center for Population Biology, University of California, Davis, CA95616
- Department of Evolution and Ecology, University of California, Davis, CA95616
| | - Graham Coop
- Center for Population Biology, University of California, Davis, CA95616
- Department of Evolution and Ecology, University of California, Davis, CA95616
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9
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Galtier N. Half a Century of Controversy: The Neutralist/Selectionist Debate in Molecular Evolution. Genome Biol Evol 2024; 16:evae003. [PMID: 38311843 PMCID: PMC10839204 DOI: 10.1093/gbe/evae003] [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] [Accepted: 01/01/2024] [Indexed: 02/06/2024] Open
Abstract
The neutral and nearly neutral theories, introduced more than 50 yr ago, have raised and still raise passionate discussion regarding the forces governing molecular evolution and their relative importance. The debate, initially focused on the amount of within-species polymorphism and constancy of the substitution rate, has spread, matured, and now underlies a wide range of topics and questions. The neutralist/selectionist controversy has structured the field and influences the way molecular evolutionary scientists conceive their research.
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Affiliation(s)
- Nicolas Galtier
- ISEM, CNRS, IRD, Université de Montpellier, Montpellier, France
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10
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Thon FM, Müller C, Wittmann MJ. The evolution of chemodiversity in plants-From verbal to quantitative models. Ecol Lett 2024; 27:e14365. [PMID: 38362774 DOI: 10.1111/ele.14365] [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: 07/10/2023] [Revised: 10/31/2023] [Accepted: 12/09/2023] [Indexed: 02/17/2024]
Abstract
Plants harbour a great chemodiversity, that is diversity of specialised metabolites (SMs), at different scales. For instance, individuals can produce a large number of SMs, and populations can differ in their metabolite composition. Given the ecological and economic importance of plant chemodiversity, it is important to understand how it arises and is maintained over evolutionary time. For other dimensions of biodiversity, that is species diversity and genetic diversity, quantitative models play an important role in addressing such questions. Here, we provide a synthesis of existing hypotheses and quantitative models, that is mathematical models and computer simulations, for the evolution of plant chemodiversity. We describe each model's ingredients, that is the biological processes that shape chemodiversity, the scales it considers and whether it has been formalized as a quantitative model. Although we identify several quantitative models, not all are dynamic and many influential models have remained verbal. To fill these gaps, we outline our vision for the future of chemodiversity modelling. We identify quantitative models used for genetic variation that may be adapted for chemodiversity, and we present a flexible framework for the creation of individual-based models that address different scales of chemodiversity and combine different ingredients that bring this chemodiversity about.
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Affiliation(s)
- Frans M Thon
- Faculty of Biology, Theoretical Biology, Bielefeld University, Bielefeld, Germany
| | - Caroline Müller
- Faculty of Biology, Chemical Ecology, Bielefeld University, Bielefeld, Germany
- Joint Institute for Individualisation in a Changing Environment (JICE), University of Münster and Bielefeld University, Bielefeld, Germany
| | - Meike J Wittmann
- Faculty of Biology, Theoretical Biology, Bielefeld University, Bielefeld, Germany
- Joint Institute for Individualisation in a Changing Environment (JICE), University of Münster and Bielefeld University, Bielefeld, Germany
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11
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de Jong MJ, van Oosterhout C, Hoelzel AR, Janke A. Moderating the neutralist-selectionist debate: exactly which propositions are we debating, and which arguments are valid? Biol Rev Camb Philos Soc 2024; 99:23-55. [PMID: 37621151 DOI: 10.1111/brv.13010] [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: 03/15/2022] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/26/2023]
Abstract
Half a century after its foundation, the neutral theory of molecular evolution continues to attract controversy. The debate has been hampered by the coexistence of different interpretations of the core proposition of the neutral theory, the 'neutral mutation-random drift' hypothesis. In this review, we trace the origins of these ambiguities and suggest potential solutions. We highlight the difference between the original, the revised and the nearly neutral hypothesis, and re-emphasise that none of them equates to the null hypothesis of strict neutrality. We distinguish the neutral hypothesis of protein evolution, the main focus of the ongoing debate, from the neutral hypotheses of genomic and functional DNA evolution, which for many species are generally accepted. We advocate a further distinction between a narrow and an extended neutral hypothesis (of which the latter posits that random non-conservative amino acid substitutions can cause non-ecological phenotypic divergence), and we discuss the implications for evolutionary biology beyond the domain of molecular evolution. We furthermore point out that the debate has widened from its initial focus on point mutations, and also concerns the fitness effects of large-scale mutations, which can alter the dosage of genes and regulatory sequences. We evaluate the validity of neutralist and selectionist arguments and find that the tested predictions, apart from being sensitive to violation of underlying assumptions, are often derived from the null hypothesis of strict neutrality, or equally consistent with the opposing selectionist hypothesis, except when assuming molecular panselectionism. Our review aims to facilitate a constructive neutralist-selectionist debate, and thereby to contribute to answering a key question of evolutionary biology: what proportions of amino acid and nucleotide substitutions and polymorphisms are adaptive?
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Affiliation(s)
- Menno J de Jong
- Senckenberg Biodiversity and Climate Research Institute (SBiK-F), Georg-Voigt-Strasse 14-16, Frankfurt am Main, 60325, Germany
| | - Cock van Oosterhout
- Centre for Ecology, Evolution and Conservation, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - A Rus Hoelzel
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Axel Janke
- Senckenberg Biodiversity and Climate Research Institute (SBiK-F), Georg-Voigt-Strasse 14-16, Frankfurt am Main, 60325, Germany
- Institute for Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Strasse 9, Frankfurt am Main, 60438, Germany
- LOEWE-Centre for Translational Biodiversity Genomics (TBG), Senckenberg Nature Research Society, Georg-Voigt-Straße 14-16, Frankfurt am Main, 60325, Germany
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12
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Forsdyke DR. Speciation, natural selection, and networks: three historians versus theoretical population geneticists. Theory Biosci 2024; 143:1-26. [PMID: 38282046 DOI: 10.1007/s12064-024-00412-9] [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: 02/03/2023] [Accepted: 01/06/2024] [Indexed: 01/30/2024]
Abstract
In 1913, the geneticist William Bateson called for a halt in studies of genetic phenomena until evolutionary fundamentals had been sufficiently addressed at the molecular level. Nevertheless, in the 1960s, the theoretical population geneticists celebrated a "modern synthesis" of the teachings of Mendel and Darwin, with an exclusive role for natural selection in speciation. This was supported, albeit with minor reservations, by historians Mark Adams and William Provine, who taught it to generations of students. In subsequent decades, doubts were raised by molecular biologists and, despite the deep influence of various mentors, Adams and Provine noted serious anomalies and began to question traditional "just-so-stories." They were joined in challenging the genetic orthodoxy by a scientist-historian, Donald Forsdyke, who suggested that a "collective variation" postulated by Darwin's young research associate, George Romanes, and a mysterious "residue" postulated by Bateson, might relate to differences in short runs of DNA bases (oligonucleotides). The dispute between a small network of historians and a large network of geneticists can be understood in the context of national politics. Contrasts are drawn between democracies, where capturing the narrative makes reversal difficult, and dictatorships, where overthrow of a supportive dictator can result in rapid reversal.
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Affiliation(s)
- Donald R Forsdyke
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, K7L3N6, Canada.
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13
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van der Valk T, Jensen A, Caillaud D, Guschanski K. Comparative genomic analyses provide new insights into evolutionary history and conservation genomics of gorillas. BMC Ecol Evol 2024; 24:14. [PMID: 38273244 PMCID: PMC10811819 DOI: 10.1186/s12862-023-02195-x] [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: 06/30/2023] [Accepted: 12/22/2023] [Indexed: 01/27/2024] Open
Abstract
Genome sequencing is a powerful tool to understand species evolutionary history, uncover genes under selection, which could be informative of local adaptation, and infer measures of genetic diversity, inbreeding and mutational load that could be used to inform conservation efforts. Gorillas, critically endangered primates, have received considerable attention and with the recently sequenced Bwindi mountain gorilla population, genomic data is now available from all gorilla subspecies and both mountain gorilla populations. Here, we reanalysed this rich dataset with a focus on evolutionary history, local adaptation and genomic parameters relevant for conservation. We estimate a recent split between western and eastern gorillas of 150,000-180,000 years ago, with gene flow around 20,000 years ago, primarily between the Cross River and Grauer's gorilla subspecies. This gene flow event likely obscures evolutionary relationships within eastern gorillas: after excluding putatively introgressed genomic regions, we uncover a sister relationship between Virunga mountain gorillas and Grauer's gorillas to the exclusion of Bwindi mountain gorillas. This makes mountain gorillas paraphyletic. Eastern gorillas are less genetically diverse and more inbred than western gorillas, yet we detected lower genetic load in the eastern species. Analyses of indels fit remarkably well with differences in genetic diversity across gorilla taxa as recovered with nucleotide diversity measures. We also identified genes under selection and unique gene variants specific for each gorilla subspecies, encoding, among others, traits involved in immunity, diet, muscular development, hair morphology and behavior. The presence of this functional variation suggests that the subspecies may be locally adapted. In conclusion, using extensive genomic resources we provide a comprehensive overview of gorilla genomic diversity, including a so-far understudied Bwindi mountain gorilla population, identify putative genes involved in local adaptation, and detect population-specific gene flow across gorilla species.
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Affiliation(s)
- Tom van der Valk
- Centre for Palaeogenetics, Stockholm, Sweden.
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden.
- SciLifeLab, Stockholm, Sweden.
- Department of Zoology, Stockholm University, Stockholm, Sweden.
| | - Axel Jensen
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Damien Caillaud
- Department of Anthropology, University of CA - Davis, Davis, California, USA
| | - Katerina Guschanski
- SciLifeLab, Stockholm, Sweden
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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14
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Thom G, Moreira LR, Batista R, Gehara M, Aleixo A, Smith BT. Genomic Architecture Predicts Tree Topology, Population Structuring, and Demographic History in Amazonian Birds. Genome Biol Evol 2024; 16:evae002. [PMID: 38236173 PMCID: PMC10823491 DOI: 10.1093/gbe/evae002] [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: 05/09/2023] [Revised: 10/26/2023] [Accepted: 12/12/2023] [Indexed: 01/19/2024] Open
Abstract
Geographic barriers are frequently invoked to explain genetic structuring across the landscape. However, inferences on the spatial and temporal origins of population variation have been largely limited to evolutionary neutral models, ignoring the potential role of natural selection and intrinsic genomic processes known as genomic architecture in producing heterogeneity in differentiation across the genome. To test how variation in genomic characteristics (e.g. recombination rate) impacts our ability to reconstruct general patterns of differentiation between species that cooccur across geographic barriers, we sequenced the whole genomes of multiple bird populations that are distributed across rivers in southeastern Amazonia. We found that phylogenetic relationships within species and demographic parameters varied across the genome in predictable ways. Genetic diversity was positively associated with recombination rate and negatively associated with species tree support. Gene flow was less pervasive in genomic regions of low recombination, making these windows more likely to retain patterns of population structuring that matched the species tree. We further found that approximately a third of the genome showed evidence of selective sweeps and linked selection, skewing genome-wide estimates of effective population sizes and gene flow between populations toward lower values. In sum, we showed that the effects of intrinsic genomic characteristics and selection can be disentangled from neutral processes to elucidate spatial patterns of population differentiation.
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Affiliation(s)
- Gregory Thom
- Department of Ornithology, American Museum of Natural History, New York, NY, USA
- Museum of Natural Science, Louisiana State University, Baton Rouge, LA, USA
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Lucas Rocha Moreira
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Vertebrate Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Romina Batista
- Programa de Coleções Biológicas, Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil
- School of Science, Engineering and Environment, University of Salford, Manchester, UK
| | - Marcelo Gehara
- Department of Earth and Environmental Sciences, Rutgers University, Newark, NJ, USA
| | - Alexandre Aleixo
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
- Department of Environmental Genomics, Instituto Tecnológico Vale, Belém, Brazil
| | - Brian Tilston Smith
- Department of Ornithology, American Museum of Natural History, New York, NY, USA
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15
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Schrider DR. Allelic gene conversion softens selective sweeps. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570141. [PMID: 38106127 PMCID: PMC10723294 DOI: 10.1101/2023.12.05.570141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The prominence of positive selection, in which beneficial mutations are favored by natural selection and rapidly increase in frequency, is a subject of intense debate. Positive selection can result in selective sweeps, in which the haplotype(s) bearing the adaptive allele "sweep" through the population, thereby removing much of the genetic diversity from the region surrounding the target of selection. Two models of selective sweeps have been proposed: classical sweeps, or "hard sweeps", in which a single copy of the adaptive allele sweeps to fixation, and "soft sweeps", in which multiple distinct copies of the adaptive allele leave descendants after the sweep. Soft sweeps can be the outcome of recurrent mutation to the adaptive allele, or the presence of standing genetic variation consisting of multiple copies of the adaptive allele prior to the onset of selection. Importantly, soft sweeps will be common when populations can rapidly adapt to novel selective pressures, either because of a high mutation rate or because adaptive alleles are already present. The prevalence of soft sweeps is especially controversial, and it has been noted that selection on standing variation or recurrent mutations may not always produce soft sweeps. Here, we show that the inverse is true: selection on single-origin de novo mutations may often result in an outcome that is indistinguishable from a soft sweep. This is made possible by allelic gene conversion, which "softens" hard sweeps by copying the adaptive allele onto multiple genetic backgrounds, a process we refer to as a "pseudo-soft" sweep. We carried out a simulation study examining the impact of gene conversion on sweeps from a single de novo variant in models of human, Drosophila, and Arabidopsis populations. The fraction of simulations in which gene conversion had produced multiple haplotypes with the adaptive allele upon fixation was appreciable. Indeed, under realistic demographic histories and gene conversion rates, even if selection always acts on a single-origin mutation, sweeps involving multiple haplotypes are more likely than hard sweeps in large populations, especially when selection is not extremely strong. Thus, even when the mutation rate is low or there is no standing variation, hard sweeps are expected to be the exception rather than the rule in large populations. These results also imply that the presence of signatures of soft sweeps does not necessarily mean that adaptation has been especially rapid or is not mutation limited.
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Affiliation(s)
- Daniel R Schrider
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599
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Jaisamut K, Pitiwararom R, Sukawutthiya P, Sathirapatya T, Noh H, Worrapitirungsi W, Vongpaisarnsin K. Unraveling the mitochondrial phylogenetic landscape of Thailand reveals complex admixture and demographic dynamics. Sci Rep 2023; 13:20396. [PMID: 37990137 PMCID: PMC10663463 DOI: 10.1038/s41598-023-47762-w] [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: 08/31/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023] Open
Abstract
The evolutionary dynamics of mitochondrial DNA within the Thai population were comprehensively explored with a specific focus on the influence of South Asian admixture. A total of 166 samples were collected through randomized sampling, ensuring a diverse representation. Our findings unveil substantial genetic and haplogroup diversity within the Thai population. We have identified 164 haplotypes categorized into 97 haplogroups, with a notable inclusion of 20 novel haplogroups. The distribution of haplogroups exhibited variations across different populations and countries. The central Thai population displayed a high diversity of haplogroups from both the M and N clades. Maternal lineage affinities were discerned between several Mainland Southeast Asia (MSEA) and South Asian populations, implying ancestral genetic connections and a substantial influence of South Asian women in establishing these relationships. f4-statistics indicates the presence of a Tibeto-Burman genetic component within the Mon population from Thailand. New findings demonstrate two phases of population expansion occurring 22,000-26,000 and 2500-3800 years ago, coinciding with the Last Glacial Maximum, and Neolithic demographic transition, respectively. This research significantly enhances our understanding of the maternal genetic history of Thailand and MSEA, emphasizing the influence of South Asian admixture. Moreover, it underscores the critical role of prior information, such as mutation rates, within the Bayesian framework for accurate estimation of coalescence times and inferring demographic history.
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Affiliation(s)
- Kitipong Jaisamut
- Forensic Genetics Research Unit, Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Rachtipan Pitiwararom
- Forensic Genetics Research Unit, Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Poonyapat Sukawutthiya
- Forensic Genetics Research Unit, Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Tikumphorn Sathirapatya
- Forensic Genetics Research Unit, Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Hasnee Noh
- Forensic Genetics Research Unit, Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Wikanda Worrapitirungsi
- Forensic Genetics Research Unit, Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Kornkiat Vongpaisarnsin
- Forensic Genetics Research Unit, Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
- Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
- Forensic Serology and DNA, King Chulalongkorn Memorial Hospital and Thai Red Cross Society, Bangkok, Thailand.
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17
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Bush ZD, Naftaly AFS, Dinwiddie D, Albers C, Hillers KJ, Libuda DE. Comprehensive detection of structural variation and transposable element differences between wild type laboratory lineages of C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.13.523974. [PMID: 37961628 PMCID: PMC10634987 DOI: 10.1101/2023.01.13.523974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Genomic structural variations (SVs) and transposable elements (TEs) can be significant contributors to genome evolution, altered gene expression, and risk of genetic diseases. Recent advancements in long-read sequencing have greatly improved the quality of de novo genome assemblies and enhanced the detection of sequence variants at the scale of hundreds or thousands of bases. Comparisons between two diverged wild isolates of Caenorhabditis elegans, the Bristol and Hawaiian strains, have been widely utilized in the analysis of small genetic variations. Genetic drift, including SVs and rearrangements of repeated sequences such as TEs, can occur over time from long-term maintenance of wild type isolates within the laboratory. To comprehensively detect both large and small structural variations as well as TEs due to genetic drift, we generated de novo genome assemblies and annotations for each strain from our lab collection using both long- and short-read sequencing and compared our assemblies and annotations with that of other lab wild type strains. Within our lab assemblies, we annotate over 3.1Mb of sequence divergence between the Bristol and Hawaiian isolates: 337,584 SNPs, 94,503 small insertion-deletions (<50bp), and 4,334 structural variations (>50bp). Further, we define the location and movement of specific DNA TEs between N2 Bristol and CB4856 Hawaiian wild type isolates. Specifically, we find the N2 Bristol genome has 20.6% more TEs from the Tc1/mariner family than the CB4856 Hawaiian genome. Moreover, we identified Zator elements as the most abundant and mobile TE family in the genome. Using specific TE sequences with unique SNPs, we also identify 38 TEs that moved intrachromosomally and 9 TEs that moved interchromosomally between the N2 Bristol and CB4856 Hawaiian genomes. By comparing the de novo genome assembly of our lab collection Bristol isolate to the VC2010 Bristol assembly, we also reveal that lab lineages display over 2 Mb of total variation: 1,162 SNPs, 1,528 indels, and 897 SVs with 95% of the variation due to SVs. Overall, our work demonstrates the unique contribution of SVs and TEs to variation and genetic drift between wild type laboratory strains assumed to be isogenic despite growing evidence of genetic drift and phenotypic variation.
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Affiliation(s)
- Zachary D. Bush
- Institute of Molecular Biology, Department of Biology, University of Oregon, 1229 Franklin Blvd Eugene, OR 97403, USA
| | - Alice F. S. Naftaly
- Institute of Molecular Biology, Department of Biology, University of Oregon, 1229 Franklin Blvd Eugene, OR 97403, USA
| | - Devin Dinwiddie
- Institute of Molecular Biology, Department of Biology, University of Oregon, 1229 Franklin Blvd Eugene, OR 97403, USA
| | - Cora Albers
- Institute of Molecular Biology, Department of Biology, University of Oregon, 1229 Franklin Blvd Eugene, OR 97403, USA
| | - Kenneth J. Hillers
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - Diana E. Libuda
- Institute of Molecular Biology, Department of Biology, University of Oregon, 1229 Franklin Blvd Eugene, OR 97403, USA
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18
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Rodrigues MF, Kern AD, Ralph PL. Shared evolutionary processes shape landscapes of genomic variation in the great apes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.07.527547. [PMID: 36798346 PMCID: PMC9934647 DOI: 10.1101/2023.02.07.527547] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
For at least the past five decades population genetics, as a field, has worked to describe the precise balance of forces that shape patterns of variation in genomes. The problem is challenging because modelling the interactions between evolutionary processes is difficult, and different processes can impact genetic variation in similar ways. In this paper, we describe how diversity and divergence between closely related species change with time, using correlations between landscapes of genetic variation as a tool to understand the interplay between evolutionary processes. We find strong correlations between landscapes of diversity and divergence in a well sampled set of great ape genomes, and explore how various processes such as incomplete lineage sorting, mutation rate variation, GC-biased gene conversion and selection contribute to these correlations. Through highly realistic, chromosome-scale, forward-in-time simulations we show that the landscapes of diversity and divergence in the great apes are too well correlated to be explained via strictly neutral processes alone. Our best fitting simulation includes both deleterious and beneficial mutations in functional portions of the genome, in which 9% of fixations within those regions is driven by positive selection. This study provides a framework for modelling genetic variation in closely related species, an approach which can shed light on the complex balance of forces that have shaped genetic variation.
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Affiliation(s)
- Murillo F. Rodrigues
- Institute of Ecology and Evolution, University of Oregon
- Department of Biology, University of Oregon
| | - Andrew D. Kern
- Institute of Ecology and Evolution, University of Oregon
- Department of Biology, University of Oregon
| | - Peter L. Ralph
- Institute of Ecology and Evolution, University of Oregon
- Department of Biology, University of Oregon
- Department of Mathematics, University of Oregon
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19
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Murga-Moreno J, Casillas S, Barbadilla A, Uricchio L, Enard D. An efficient and robust ABC approach to infer the rate and strength of adaptation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.29.555322. [PMID: 37693550 PMCID: PMC10491248 DOI: 10.1101/2023.08.29.555322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Inferring the effects of positive selection on genomes remains a critical step in characterizing the ultimate and proximate causes of adaptation across species, and quantifying positive selection remains a challenge due to the confounding effects of many other evolutionary processes. Robust and efficient approaches for adaptation inference could help characterize the rate and strength of adaptation in non-model species for which demographic history, mutational processes, and recombination patterns are not currently well-described. Here, we introduce an efficient and user-friendly extension of the McDonald-Kreitman test (ABC-MK) for quantifying long-term protein adaptation in specific lineages of interest. We characterize the performance of our approach with forward simulations and find that it is robust to many demographic perturbations and positive selection configurations, demonstrating its suitability for applications to non-model genomes. We apply ABC-MK to the human proteome and a set of known Virus Interacting Proteins (VIPs) to test the long-term adaptation in genes interacting with viruses. We find substantially stronger signatures of positive selection on RNA-VIPs than DNA-VIPs, suggesting that RNA viruses may be an important driver of human adaptation over deep evolutionary time scales.
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Affiliation(s)
- Jesús Murga-Moreno
- University of Arizona Department of Ecology and Evolutionary Biology, Tucson, USA
| | - Sònia Casillas
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Antonio Barbadilla
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | | | - David Enard
- University of Arizona Department of Ecology and Evolutionary Biology, Tucson, USA
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20
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Kampuansai J, Wongkomonched R, Kutanan W, Srikummool M, Seetaraso T, Sathupak S, Thongkumkoon P, Sangphukieo A. Genetic diversity and ancestry of the Khmuic-speaking ethnic groups in Thailand: a genome-wide perspective. Sci Rep 2023; 13:15710. [PMID: 37735611 PMCID: PMC10514191 DOI: 10.1038/s41598-023-43060-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 09/19/2023] [Indexed: 09/23/2023] Open
Abstract
The Khmuic-speaking populations are believed to be the descendants of one of the earliest groups to settle in Mainland Southeast Asia. In Thailand, there are two agricultural Khmuic-speaking ethnic groups, the Khamu and Lua (Htin). These peoples primarily reside in scattered locations along the mountainous Thailand-Laos border in Nan province. In this study, we conducted genome-wide SNP analysis on 81 individuals from three Khamu and two Lua villages in northern Thailand. Our findings revealed that both the Khamu and Lua groups possess genetic structures that are distinct from other ethnicities in Southeast Asia, indicating a unique history of migration and settlement. Within the Khmuic group, the Khamu populations living in different locations exhibited similar genetic structures and displayed genetic affinities only with some hill-tribes and Tai-Kadai (Kra-Dai)-speaking groups in Thailand, suggesting potential intermixing or cultural exchange. Furthermore, the Lua people displayed a distinctive population structure, which could be attributed to the founder effect and endogamous marriage practices. Additionally, we discovered a relationship between the Khmuic-speaking populations in Thailand and a Neolithic ancient sample obtained from the Tham Pha Ling archaeological site in Laos. This study provides new insight into genetic substructure within the Khmuic-speaking people and their potential relationship to the indigenous inhabitants of Mainland Southeast Asia.
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Affiliation(s)
- Jatupol Kampuansai
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.
| | - Rattanasak Wongkomonched
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Wibhu Kutanan
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Metawee Srikummool
- Department of Biochemistry, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Tanapon Seetaraso
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Suwapat Sathupak
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Patcharawadee Thongkumkoon
- Center of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Apiwat Sangphukieo
- Center of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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21
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Yan W, Wang Z, Zhou B. Population evolution of seagrasses returning to the ocean. Heliyon 2023; 9:e20231. [PMID: 37809433 PMCID: PMC10559988 DOI: 10.1016/j.heliyon.2023.e20231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/05/2023] [Accepted: 09/14/2023] [Indexed: 10/10/2023] Open
Abstract
Seagrasses are higher flowering plants that live entirely in marine environments, with the greatest habitat variation occurring from land to sea. Genetic structure or population differentiation history is a hot topic in evolutionary biology, which is of great significance for understanding speciation. Genetic information is obtained from geographically distributed subpopulations, different subspecies, or strains of the same species using next-generation sequencing techniques. Genetic variation is identified by comparison with reference genomes. Genetic diversity is explored using population structure, principal component analysis (PCA), and phylogenetic relationships. Patterns of population genetic differentiation are elucidated by combining the isolation by distance (IBD) model, linkage disequilibrium levels, and genetic statistical analysis. Demographic history is simulated using effective population size, divergence time, and site frequency spectrum (SFS). Through various population genetic analyses, the genetic structure and historical population dynamics of seagrass can be clarified, and their evolutionary processes can be further explored at the molecular level to understand how evolutionary processes contributed to the formation of early ecological species and provide data support for seagrass conservation.
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Affiliation(s)
- Wenjie Yan
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Zhaohua Wang
- First Institute of Oceanography, MNR, Qingdao, 266061, China
| | - Bin Zhou
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
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22
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Herrick J. Kimura's Theory of Non-Adaptive Radiation and Peto's Paradox: A Missing Link? BIOLOGY 2023; 12:1140. [PMID: 37627024 PMCID: PMC10452704 DOI: 10.3390/biology12081140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/07/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023]
Abstract
Karyotype diversity reflects genome integrity and stability. A strong correlation between karyotype diversity and species richness, meaning the number of species in a phylogenetic clade, was first reported in mammals over forty years ago: in mammalian phylogenetic clades, the standard deviation of karyotype diversity (KD) closely corresponded to species richness (SR) at the order level. These initial studies, however, did not control for phylogenetic signal, raising the possibility that the correlation was due to phylogenetic relatedness among species in a clade. Accordingly, karyotype diversity trivially reflects species richness simply as a passive consequence of adaptive radiation. A more recent study in mammals controlled for phylogenetic signals and established the correlation as phylogenetically independent, suggesting that species richness cannot, in itself, explain the observed corresponding karyotype diversity. The correlation is, therefore, remarkable because the molecular mechanisms contributing to karyotype diversity are evolutionarily independent of the ecological mechanisms contributing to species richness. Recently, it was shown in salamanders that the two processes generating genome size diversity and species richness were indeed independent and operate in parallel, suggesting a potential non-adaptive, non-causal but biologically meaningful relationship. KD depends on mutational input generating genetic diversity and reflects genome stability, whereas species richness depends on ecological factors and reflects natural selection acting on phenotypic diversity. As mutation and selection operate independently and involve separate and unrelated evolutionary mechanisms-there is no reason a priori to expect such a strong, let alone any, correlation between KD and SR. That such a correlation exists is more consistent with Kimura's theory of non-adaptive radiation than with ecologically based adaptive theories of macro-evolution, which are not excluded in Kimura's non-adaptive theory. The following reviews recent evidence in support of Kimura's proposal, and other findings that contribute to a wider understanding of the molecular mechanisms underlying the process of non-adaptive radiation.
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Affiliation(s)
- John Herrick
- Independent Researcher, 3, rue des Jeûneurs, 75002 Paris, France
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23
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Richardson R, Feigin CY, Bano-Otalora B, Johnson MR, Allen AE, Park J, McDowell RJ, Mereby SA, Lin IH, Lucas RJ, Mallarino R. The genomic basis of temporal niche evolution in a diurnal rodent. Curr Biol 2023; 33:3289-3298.e6. [PMID: 37480852 PMCID: PMC10529858 DOI: 10.1016/j.cub.2023.06.068] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 05/05/2023] [Accepted: 06/26/2023] [Indexed: 07/24/2023]
Abstract
Patterns of diel activity-how animals allocate their activity throughout the 24-h daily cycle-play key roles in shaping the internal physiology of an animal and its relationship with the external environment.1,2,3,4,5 Although shifts in diel activity patterns have occurred numerous times over the course of vertebrate evolution,6 the genomic correlates of such transitions remain unknown. Here, we use the African striped mouse (Rhabdomys pumilio), a species that transitioned from the ancestrally nocturnal diel niche of its close relatives to a diurnal one,7,8,9,10,11 to define patterns of naturally occurring molecular variation in diel niche traits. First, to facilitate genomic analyses, we generate a chromosome-level genome assembly of the striped mouse. Next, using transcriptomics, we show that the switch to daytime activity in this species is associated with a realignment of daily rhythms in peripheral tissues with respect to the light:dark cycle and the central circadian clock. To uncover selection pressures associated with this temporal niche shift, we perform comparative genomic analyses with closely related rodent species and find evidence of relaxation of purifying selection on striped mouse genes in the rod phototransduction pathway. In agreement with this, electroretinogram measurements demonstrate that striped mice have functional differences in dim-light visual responses compared with nocturnal rodents. Taken together, our results show that striped mice have undergone a drastic change in circadian organization and provide evidence that the visual system has been a major target of selection as this species transitioned to a novel temporal niche.
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Affiliation(s)
- Rose Richardson
- Centre for Biological Timing, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Division of Neuroscience, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Charles Y Feigin
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA; School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Beatriz Bano-Otalora
- Centre for Biological Timing, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Division of Neuroscience, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Division of Diabetes, Endocrinology, & Gastroenterology, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Matthew R Johnson
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Annette E Allen
- Centre for Biological Timing, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Division of Neuroscience, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Jongbeom Park
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Richard J McDowell
- Centre for Biological Timing, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Division of Neuroscience, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Sarah A Mereby
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - I-Hsuan Lin
- Bioinformatics Core Facility, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PL, UK
| | - Robert J Lucas
- Centre for Biological Timing, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Division of Neuroscience, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK.
| | - Ricardo Mallarino
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA.
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24
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Forsythe D, Hsu JL. Neutral theory and beyond: A systematic review of molecular evolution education. Ecol Evol 2023; 13:e10365. [PMID: 37529584 PMCID: PMC10375367 DOI: 10.1002/ece3.10365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/07/2023] [Accepted: 07/14/2023] [Indexed: 08/03/2023] Open
Abstract
Molecular evolution-including the neutral theory of molecular evolution-is a major sub-discipline of evolution and is widely taught in undergraduate evolution courses. However, despite its ubiquity, there have not been any previous attempts to compile and review the molecular evolution education literature. Here, we draw upon the framework proposed in a past literature review examining the broader evolution education landscape to conduct a literature review of papers related to molecular evolution education, classifying the contributions of such papers to evolution pedagogy as well as evolution education research. We find that there remains very limited coverage of molecular evolution in the education literature, with existing papers focusing primarily on providing new instructional modules and strategies for teaching molecular evolution. Our work suggests several areas of critical need as well as opportunities to advance evolution education and evolution education research, including compiling instructional goals for the sub-discipline, developing validated assessments, and investigating student thinking related to molecular evolution. We conclude by providing general strategies, advice, and a novel curricular activity for teaching molecular evolution and the neutral theory of molecular evolution.
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Affiliation(s)
- Desiree Forsythe
- Grand Challenges Initiative, Schmid College of Science and TechnologyChapman UniversityOrangeCaliforniaUSA
- Schmid College of Science and TechnologyChapman UniversityOrangeCaliforniaUSA
| | - Jeremy L. Hsu
- Schmid College of Science and TechnologyChapman UniversityOrangeCaliforniaUSA
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25
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Whitehouse LS, Schrider DR. Timesweeper: accurately identifying selective sweeps using population genomic time series. Genetics 2023; 224:iyad084. [PMID: 37157914 PMCID: PMC10324941 DOI: 10.1093/genetics/iyad084] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 07/25/2022] [Accepted: 04/25/2023] [Indexed: 05/10/2023] Open
Abstract
Despite decades of research, identifying selective sweeps, the genomic footprints of positive selection, remains a core problem in population genetics. Of the myriad methods that have been developed to tackle this task, few are designed to leverage the potential of genomic time-series data. This is because in most population genetic studies of natural populations, only a single period of time can be sampled. Recent advancements in sequencing technology, including improvements in extracting and sequencing ancient DNA, have made repeated samplings of a population possible, allowing for more direct analysis of recent evolutionary dynamics. Serial sampling of organisms with shorter generation times has also become more feasible due to improvements in the cost and throughput of sequencing. With these advances in mind, here we present Timesweeper, a fast and accurate convolutional neural network-based tool for identifying selective sweeps in data consisting of multiple genomic samplings of a population over time. Timesweeper analyzes population genomic time-series data by first simulating training data under a demographic model appropriate for the data of interest, training a one-dimensional convolutional neural network on said simulations, and inferring which polymorphisms in this serialized data set were the direct target of a completed or ongoing selective sweep. We show that Timesweeper is accurate under multiple simulated demographic and sampling scenarios, identifies selected variants with high resolution, and estimates selection coefficients more accurately than existing methods. In sum, we show that more accurate inferences about natural selection are possible when genomic time-series data are available; such data will continue to proliferate in coming years due to both the sequencing of ancient samples and repeated samplings of extant populations with faster generation times, as well as experimentally evolved populations where time-series data are often generated. Methodological advances such as Timesweeper thus have the potential to help resolve the controversy over the role of positive selection in the genome. We provide Timesweeper as a Python package for use by the community.
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Affiliation(s)
- Logan S Whitehouse
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Daniel R Schrider
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27514, USA
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26
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Christie MR, McNickle GG. Negative frequency dependent selection unites ecology and evolution. Ecol Evol 2023; 13:e10327. [PMID: 37484931 PMCID: PMC10361363 DOI: 10.1002/ece3.10327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 06/02/2023] [Accepted: 07/07/2023] [Indexed: 07/25/2023] Open
Abstract
From genes to communities, understanding how diversity is maintained remains a fundamental question in biology. One challenging to identify, yet potentially ubiquitous, mechanism for the maintenance of diversity is negative frequency dependent selection (NFDS), which occurs when entities (e.g., genotypes, life history strategies, species) experience a per capita reduction in fitness with increases in relative abundance. Because NFDS allows rare entities to increase in frequency while preventing abundant entities from excluding others, we posit that negative frequency dependent selection plays a central role in the maintenance of diversity. In this review, we relate NFDS to coexistence, identify mechanisms of NFDS (e.g., mutualism, predation, parasitism), review strategies for identifying NFDS, and distinguish NFDS from other mechanisms of coexistence (e.g., storage effects, fluctuating selection). We also emphasize that NFDS is a key place where ecology and evolution intersect. Specifically, there are many examples of frequency dependent processes in ecology, but fewer cases that link this process to selection. Similarly, there are many examples of selection in evolution, but fewer cases that link changes in trait values to negative frequency dependence. Bridging these two well-developed fields of ecology and evolution will allow for mechanistic insights into the maintenance of diversity at multiple levels.
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Affiliation(s)
- Mark R. Christie
- Department of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
- Department of Forestry and Natural ResourcesPurdue UniversityWest LafayetteIndianaUSA
| | - Gordon G. McNickle
- Department of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
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27
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Van Cleve J. Evolutionarily stable strategy analysis and its links to demography and genetics through invasion fitness. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210496. [PMID: 36934754 PMCID: PMC10024993 DOI: 10.1098/rstb.2021.0496] [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: 11/16/2022] [Accepted: 02/07/2023] [Indexed: 03/21/2023] Open
Abstract
Evolutionarily stable strategy (ESS) analysis pioneered by Maynard Smith and Price took off in part because it often does not require explicit assumptions about the genetics and demography of a population in contrast to population genetic models. Though this simplicity is useful, it obscures the degree to which ESS analysis applies to populations with more realistic genetics and demography: for example, how does ESS analysis handle complexities such as kin selection, group selection and variable environments when phenotypes are affected by multiple genes? In this paper, I review the history of the ESS concept and show how early uncertainty about the method lead to important mathematical theory linking ESS analysis to general population genetic models. I use this theory to emphasize the link between ESS analysis and the concept of invasion fitness. I give examples of how invasion fitness can measure kin selection, group selection and the evolution of linked modifier genes in response to variable environments. The ESSs in these examples depend crucially on demographic and genetic parameters, which highlights how ESS analysis will continue to be an important tool in understanding evolutionary patterns as new models address the increasing abundance of genetic and long-term demographic data in natural populations. This article is part of the theme issue 'Half a century of evolutionary games: a synthesis of theory, application and future directions'.
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Affiliation(s)
- Jeremy Van Cleve
- Department of Biology, University of Kentucky, Lexington, KY 40506 USA
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28
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Barroso GV, Lohmueller KE. Inferring the mode and strength of ongoing selection. Genome Res 2023; 33:632-643. [PMID: 37055196 PMCID: PMC10234300 DOI: 10.1101/gr.276386.121] [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: 11/12/2021] [Accepted: 03/29/2023] [Indexed: 04/15/2023]
Abstract
Genome sequence data are no longer scarce. The UK Biobank alone comprises 200,000 individual genomes, with more on the way, leading the field of human genetics toward sequencing entire populations. Within the next decades, other model organisms will follow suit, especially domesticated species such as crops and livestock. Having sequences from most individuals in a population will present new challenges for using these data to improve health and agriculture in the pursuit of a sustainable future. Existing population genetic methods are designed to model hundreds of randomly sampled sequences but are not optimized for extracting the information contained in the larger and richer data sets that are beginning to emerge, with thousands of closely related individuals. Here we develop a new method called trio-based inference of dominance and selection (TIDES) that uses data from tens of thousands of family trios to make inferences about natural selection acting in a single generation. TIDES further improves on the state of the art by making no assumptions regarding demography, linkage, or dominance. We discuss how our method paves the way for studying natural selection from new angles.
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Affiliation(s)
- Gustavo V Barroso
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095-1606, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| | - Kirk E Lohmueller
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095-1606, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
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29
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Fluctuating selection and the determinants of genetic variation. Trends Genet 2023; 39:491-504. [PMID: 36890036 DOI: 10.1016/j.tig.2023.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 02/01/2023] [Accepted: 02/07/2023] [Indexed: 03/08/2023]
Abstract
Recent studies of cosmopolitan Drosophila populations have found hundreds to thousands of genetic loci with seasonally fluctuating allele frequencies, bringing temporally fluctuating selection to the forefront of the historical debate surrounding the maintenance of genetic variation in natural populations. Numerous mechanisms have been explored in this longstanding area of research, but these exciting empirical findings have prompted several recent theoretical and experimental studies that seek to better understand the drivers, dynamics, and genome-wide influence of fluctuating selection. In this review, we evaluate the latest evidence for multilocus fluctuating selection in Drosophila and other taxa, highlighting the role of potential genetic and ecological mechanisms in maintaining these loci and their impacts on neutral genetic variation.
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30
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Ghildiyal K, Panigrahi M, Kumar H, Rajawat D, Nayak SS, Lei C, Bhushan B, Dutt T. Selection signatures for fiber production in commercial species: A review. Anim Genet 2023; 54:3-23. [PMID: 36352515 DOI: 10.1111/age.13272] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/11/2022] [Accepted: 10/11/2022] [Indexed: 11/11/2022]
Abstract
Natural fibers derived from diverse animal species have gained increased attention in recent years due to their favorable environmental effects, long-term sustainability benefits, and remarkable physical and mechanical properties that make them valuable raw materials used for textile and non-textile production. Domestication and selective breeding for the economically significant fiber traits play an imperative role in shaping the genomes and, thus, positively impact the overall productivity of the various fiber-producing species. These selection pressures leave unique footprints on the genome due to alteration in the allelic frequencies at specific loci, characterizing selective sweeps. Recent advances in genomics have enabled the discovery of selection signatures across the genome using a variety of methods. The increased demand for 'green products' manufactured from natural fibers necessitates a detailed investigation of the genomes of the various fiber-producing plant and animal species to identify the candidate genes associated with important fiber attributes such as fiber diameter/fineness, color, length, and strength, among others. The objective of this review is to present a comprehensive overview of the concept of selection signature and selective sweeps, discuss the main methods used for its detection, and address the selection signature studies conducted so far in the diverse fiber-producing animal species.
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Affiliation(s)
- Kanika Ghildiyal
- Division of Animal Genetics, Indian Veterinary Research Institute, Bareilly, India
| | - Manjit Panigrahi
- Division of Animal Genetics, Indian Veterinary Research Institute, Bareilly, India
| | - Harshit Kumar
- Division of Animal Genetics, Indian Veterinary Research Institute, Bareilly, India
| | - Divya Rajawat
- Division of Animal Genetics, Indian Veterinary Research Institute, Bareilly, India
| | | | - Chuzhao Lei
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Bharat Bhushan
- Division of Animal Genetics, Indian Veterinary Research Institute, Bareilly, India
| | - Triveni Dutt
- Livestock Production and Management Section, Indian Veterinary Research Institute, Bareilly, India
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31
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Zhang J. What Has Genomics Taught An Evolutionary Biologist? GENOMICS, PROTEOMICS & BIOINFORMATICS 2023; 21:1-12. [PMID: 36720382 PMCID: PMC10373158 DOI: 10.1016/j.gpb.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/06/2023] [Accepted: 01/19/2023] [Indexed: 01/30/2023]
Abstract
Genomics, an interdisciplinary field of biology on the structure, function, and evolution of genomes, has revolutionized many subdisciplines of life sciences, including my field of evolutionary biology, by supplying huge data, bringing high-throughput technologies, and offering a new approach to biology. In this review, I describe what I have learned from genomics and highlight the fundamental knowledge and mechanistic insights gained. I focus on three broad topics that are central to evolutionary biology and beyond-variation, interaction, and selection-and use primarily my own research and study subjects as examples. In the next decade or two, I expect that the most important contributions of genomics to evolutionary biology will be to provide genome sequences of nearly all known species on Earth, facilitate high-throughput phenotyping of natural variants and systematically constructed mutants for mapping genotype-phenotype-fitness landscapes, and assist the determination of causality in evolutionary processes using experimental evolution.
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Affiliation(s)
- Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
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32
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Moreira LR, Klicka J, Smith BT. Demography and linked selection interact to shape the genomic landscape of codistributed woodpeckers during the Ice Age. Mol Ecol 2023; 32:1739-1759. [PMID: 36617622 DOI: 10.1111/mec.16841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 01/10/2023]
Abstract
The influence of genetic drift on population dynamics during Pleistocene glacial cycles is well understood, but the role of selection in shaping patterns of genomic variation during these events is less explored. We resequenced whole genomes to investigate how demography and natural selection interact to generate the genomic landscapes of Downy and Hairy Woodpecker, species codistributed in previously glaciated North America. First, we explored the spatial and temporal patterns of genomic diversity produced by neutral evolution. Next, we tested (i) whether levels of nucleotide diversity along the genome are correlated with intrinsic genomic properties, such as recombination rate and gene density, and (ii) whether different demographic trajectories impacted the efficacy of selection. Our results revealed cycles of bottleneck and expansion, and genetic structure associated with glacial refugia. Nucleotide diversity varied widely along the genome, but this variation was highly correlated between the species, suggesting the presence of conserved genomic features. In both taxa, nucleotide diversity was positively correlated with recombination rate and negatively correlated with gene density, suggesting that linked selection played a role in reducing diversity. Despite strong fluctuations in effective population size, the maintenance of relatively large populations during glaciations may have facilitated selection. Under these conditions, we found evidence that the individual demographic trajectory of populations modulated linked selection, with purifying selection being more efficient in removing deleterious alleles in large populations. These results highlight that while genome-wide variation reflects the expected signature of demographic change during climatic perturbations, the interaction of multiple processes produces a predictable and highly heterogeneous genomic landscape.
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Affiliation(s)
- Lucas R Moreira
- Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, New York, USA.,Department of Ornithology, American Museum of Natural History, New York City, New York, USA.,Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - John Klicka
- Burke Museum of Natural History and Culture and Department of Biology, University of Washington, Seattle, Washington, USA
| | - Brian Tilston Smith
- Department of Ornithology, American Museum of Natural History, New York City, New York, USA
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33
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Do Noncoding and Coding Sites in Angiosperm Chloroplast DNA Have Different Mutation Processes? Genes (Basel) 2023; 14:genes14010148. [PMID: 36672890 PMCID: PMC9858945 DOI: 10.3390/genes14010148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/30/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
Fourfold degenerate sites within coding regions and intergenic sites have both been used as estimates of neutral evolution. In chloroplast DNA, the pattern of substitution at intergenic sites is strongly dependent on the composition of the surrounding hexanucleotide composed of the three base pairs on each side, which suggests that the mutation process is highly context-dependent in this genome. This study examines the context-dependency of substitutions at fourfold degenerate sites in protein-coding regions and compares the pattern to what has been observed at intergenic sites. Overall, there is strong similarity between the two types of sites, but there are some intriguing differences. One of these is that substitutions of G and C are significantly higher at fourfold degenerate sites across a range of contexts. In fact, A → T and T → A substitutions are the only substitution types that occur at a lower rate at fourfold degenerate sites. The data are not consistent with selective constraints being responsible for the difference in substitution patterns between intergenic and fourfold degenerate sites. Rather, it is suggested that the difference may be a result of different epigenetic modifications that result in slightly different mutation patterns in coding and intergenic DNA.
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34
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Pfenninger M, Foucault Q. Population Genomic Time Series Data of a Natural Population Suggests Adaptive Tracking of Fluctuating Environmental Changes. Integr Comp Biol 2022; 62:1812-1826. [PMID: 35762661 DOI: 10.1093/icb/icac098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/07/2022] [Accepted: 06/16/2022] [Indexed: 01/05/2023] Open
Abstract
Natural populations are constantly exposed to fluctuating environmental changes that negatively affect their fitness in unpredictable ways. While theoretical models show the possibility of counteracting these environmental changes through rapid evolutionary adaptations, there have been few empirical studies demonstrating such adaptive tracking in natural populations. Here, we analyzed environmental data, fitness-related phenotyping and genomic time-series data sampled over 3 years from a natural Chironomus riparius (Diptera, Insecta) population to address this question. We show that the population's environment varied significantly on the time scale of the sampling in many selectively relevant dimensions, independently of each other. Similarly, phenotypic fitness components evolved significantly on the same temporal scale (mean 0.32 Haldanes), likewise independent from each other. The allele frequencies of 367,446 SNPs across the genome showed evidence of positive selection. Using temporal correlation of spatially coherent allele frequency changes revealed 35,574 haplotypes with more than one selected SNP. The mean selection coefficient for these haplotypes was 0.30 (s.d. = 0.68). The frequency changes of these haplotypes clustered in 46 different temporal patterns, indicating concerted, independent evolution of many polygenic traits. Nine of these patterns were strongly correlated with measured environmental variables. Enrichment analysis of affected genes suggested the implication of a wide variety of biological processes. Thus, our results suggest overall that the natural population of C. riparius tracks environmental change through rapid polygenic adaptation in many independent dimensions. This is further evidence that natural selection is pervasive at the genomic level and that evolutionary and ecological time scales may not differ at all, at least in some organisms.
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Affiliation(s)
- Markus Pfenninger
- Department Molecular Ecology, Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.,Institute for Molecular and Organismic Evolution, Johannes Gutenberg University, Johann-Joachim-Becher-Weg 7, 55128 Mainz, Germany.,LOEWE Centre for Translational Biodiversity Genomics, Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Quentin Foucault
- Department Molecular Ecology, Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.,Institute for Molecular and Organismic Evolution, Johannes Gutenberg University, Johann-Joachim-Becher-Weg 7, 55128 Mainz, Germany
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35
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Zhang Z, Blumenfeld J, Ramnauth A, Barash I, Zhou P, Levine D, Parker T, Rennert H. A common intronic single nucleotide variant modifies PKD1 expression level. Clin Genet 2022; 102:483-493. [PMID: 36029107 PMCID: PMC10947153 DOI: 10.1111/cge.14214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/26/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD), caused by mutations in PKD1 and PKD2 (PKD1/2), has unexplained phenotypic variability likely affected by environmental and other genetic factors. Approximately 10% of individuals with ADPKD phenotype have no causal mutation detected, possibly due to unrecognized risk variants of PKD1/2. This study was designed to identify risk variants of PKD genes through population genetic analyses. We used Wright's F-statistics (Fst) to evaluate common single nucleotide variants (SNVs) potentially favored by positive natural selection in PKD1 from 1000 Genomes Project (1KG) and genotyped 388 subjects from the Rogosin Institute ADPKD Data Repository. The variants with >90th percentile Fst scores underwent further investigation by in silico analysis and molecular genetics analyses. We identified a deep intronic SNV, rs3874648G> A, located in a conserved binding site of the splicing regulator Tra2-β in PKD1 intron 30. Reverse-transcription PCR (RT-PCR) of peripheral blood leukocytes (PBL) from an ADPKD patient homozygous for rs3874648-A identified an atypical PKD1 splice form. Functional analyses demonstrated that rs3874648-A allele increased Tra2-β binding affinity and activated a cryptic acceptor splice-site, causing a frameshift that introduced a premature stop codon in mRNA, thereby decreasing PKD1 full-length transcript level. PKD1 transcript levels were lower in PBL from rs3874648-G/A carriers than in rs3874648-G/G homozygotes in a small cohort of normal individuals and patients with PKD2 inactivating mutations. Our findings indicate that rs3874648G > A is a PKD1 expression modifier attenuating PKD1 expression through Tra2-β, while the derived G allele advantageously maintains PKD1 expression and is predominant in all subpopulations.
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Affiliation(s)
- Zhengmao Zhang
- Departments of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY
| | - Jon Blumenfeld
- Department of Medicine, Weill Cornell Medicine, New York, NY
- The Rogosin Institute, New York, NY
| | - Andrew Ramnauth
- Departments of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY
| | - Irina Barash
- Department of Medicine, Weill Cornell Medicine, New York, NY
- The Rogosin Institute, New York, NY
| | - Pengbo Zhou
- Departments of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY
| | - Daniel Levine
- Department of Biochemistry, Weill Cornell Medicine, New York, NY
- The Rogosin Institute, New York, NY
| | - Thomas Parker
- Department of Biochemistry, Weill Cornell Medicine, New York, NY
- The Rogosin Institute, New York, NY
| | - Hanna Rennert
- Departments of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY
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36
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Ameline C, Voegtli F, Andras J, Dexter E, Engelstädter J, Ebert D. Genetic slippage after sex maintains diversity for parasite resistance in a natural host population. SCIENCE ADVANCES 2022; 8:eabn0051. [PMID: 36399570 PMCID: PMC9674289 DOI: 10.1126/sciadv.abn0051] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Although parasite-mediated selection is a major driver of host evolution, its influence on genetic variation for parasite resistance is not yet well understood. We monitored resistance in a large population of the planktonic crustacean Daphnia magna over 8 years, as it underwent yearly epidemics of the bacterial pathogen Pasteuria ramosa. We observed cyclic dynamics of resistance: Resistance increased throughout the epidemics, but susceptibility was restored each spring when hosts hatched from sexual resting stages. Host resting stages collected across the year showed that largely resistant host populations can produce susceptible sexual offspring. A genetic model of resistance developed for this host-parasite system, based on multiple loci and strong epistasis, is in partial agreement with our findings. Our results reveal that, despite strong selection for resistance in a natural host population, genetic slippage after sexual reproduction can be a strong factor for the maintenance of genetic diversity of host resistance.
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Affiliation(s)
- Camille Ameline
- Department of Environmental Sciences, Zoology, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
| | - Felix Voegtli
- Department of Environmental Sciences, Zoology, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
| | - Jason Andras
- Department of Environmental Sciences, Zoology, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
| | - Eric Dexter
- Department of Environmental Sciences, Zoology, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
| | - Jan Engelstädter
- School of Biological Sciences, The University of Queensland, Brisbane, Australia
| | - Dieter Ebert
- Department of Environmental Sciences, Zoology, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
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Accumulation and maintenance of information in evolution. Proc Natl Acad Sci U S A 2022; 119:e2123152119. [PMID: 36037343 PMCID: PMC9457054 DOI: 10.1073/pnas.2123152119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Selection accumulates information in the genome-it guides stochastically evolving populations toward states (genotype frequencies) that would be unlikely under neutrality. This can be quantified as the Kullback-Leibler (KL) divergence between the actual distribution of genotype frequencies and the corresponding neutral distribution. First, we show that this population-level information sets an upper bound on the information at the level of genotype and phenotype, limiting how precisely they can be specified by selection. Next, we study how the accumulation and maintenance of information is limited by the cost of selection, measured as the genetic load or the relative fitness variance, both of which we connect to the control-theoretic KL cost of control. The information accumulation rate is upper bounded by the population size times the cost of selection. This bound is very general, and applies across models (Wright-Fisher, Moran, diffusion) and to arbitrary forms of selection, mutation, and recombination. Finally, the cost of maintaining information depends on how it is encoded: Specifying a single allele out of two is expensive, but one bit encoded among many weakly specified loci (as in a polygenic trait) is cheap.
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38
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Phylogenetic, Allometric, and Ecological Factors Affecting Morphological Variation in the Scapula and Humerus of Spiny Rats (Rodentia: Echimyidae). J MAMM EVOL 2022. [DOI: 10.1007/s10914-022-09617-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
AbstractLocomotion, as a fundamental function in mammals directly associated with the use of ecological resources, is expected to have anatomical structures functionally committed that evolved under intense selective pressure, possibly carrying specializations for different locomotor habits. Among caviomorph rodents, the family Echimyidae stands out for having the greatest species richness, with relatively well-resolved phylogenetic relationships, wide variation in body mass, and remarkable diversity of locomotor habits, including arboreal, scansorial, semi-aquatic, semifossorial, and terrestrial forms. Thus, Echimyidae constitutes a promising model for understanding how phylogenetic, allometric, and ecological factors affect the evolution of postcranial structures directly linked to locomotor function. We investigated the influence of these three factors on scapular and humeral morphological variation in 38 echimyid species using two-dimensional geometric morphometry and phylogenetically informed comparative methods. Scapular and humeral shape variation had a low correlation with body mass and structure size, conveying a small or negligible allometric effect. Conversely, a significant moderate to strong phylogenetic signal was detected in both structures, suggesting that an important part of their morphometric variation results from shared evolutionary history. Notably, morphological variation of the scapula was extensively structured by phylogeny, without the marked influence of locomotor habits, suggesting that its shape may be a suitable taxonomic marker. Finally, locomotor habits were important in structuring the morphological variation of the humerus. Our results suggest that the morphologies of the scapula and humerus, despite being anatomically and functionally interconnected, were differentially shaped by ecological factors associated with locomotor habits.
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Gu X. d N/d S-H, a New Test to Distinguish Different Selection Modes in Protein Evolution and Cancer Evolution. J Mol Evol 2022; 90:342-351. [PMID: 35920867 DOI: 10.1007/s00239-022-10064-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 06/14/2022] [Indexed: 11/25/2022]
Abstract
One of the most popular measures in the analysis of protein sequence evolution is the ratio of nonsynonymous distance (dN) to synonymous distance (dS). Under the assumption that synonymous substitutions in the coding region are selectively neutral, the dN/dS ratio can be used to statistically detect the adaptive evolution (or purifying selection) if dN/dS > 1 (or dN/dS < 1) significantly. However, due to strong structural constraints and/or variable functional constraints imposed on amino acid sites, most encoding genes in most species have demonstrated dN/dS < 1. Consequently, the statistical power for testing dN/dS = 1 may be insufficient to distinguish between different selection modes. In this paper, we propose a more powerful test, called dN/dS-H, in which a new parameter H, a relative measure of rate variation among sites, was introduced. Given the condition of strong purifying selections at some sites, the dN/dS-H model predicts dN/dS = 1-H for neutral evolution, dN/dS < 1-H for nearly neutral selection, and dN/dS > 1-H for adaptive evolution. The potential of this new method for resolving the neutral-adaptive debates is illustrated by the protein sequence evolution in vertebrates, Drosophila and yeasts, as well as somatic cancer evolution (specialized as the CN/CS-H test).
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Affiliation(s)
- Xun Gu
- The Laurence H. Baker Center in Bioinformatics on Biological Statistics, Iowa State University, Ames, IA, 50011, USA. .,Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA. .,Program of Ecological and Evolutionary Biology, Iowa State University, Ames, IA, 50011, USA.
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40
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Abstract
We discuss the genetic, demographic, and selective forces that are likely to be at play in restricting observed levels of DNA sequence variation in natural populations to a much smaller range of values than would be expected from the distribution of census population sizes alone-Lewontin's Paradox. While several processes that have previously been strongly emphasized must be involved, including the effects of direct selection and genetic hitchhiking, it seems unlikely that they are sufficient to explain this observation without contributions from other factors. We highlight a potentially important role for the less-appreciated contribution of population size change; specifically, the likelihood that many species and populations may be quite far from reaching the relatively high equilibrium diversity values that would be expected given their current census sizes.
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Affiliation(s)
- Brian Charlesworth
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jeffrey D Jensen
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
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41
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Branch HA, Klingler AN, Byers KJRP, Panofsky A, Peers D. Discussions of the "Not So Fit": How Ableism Limits Diverse Thought and Investigative Potential in Evolutionary Biology. Am Nat 2022; 200:101-113. [PMID: 35737982 DOI: 10.1086/720003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
AbstractEvolutionary biology and many of its foundational concepts are grounded in a history of ableism and eugenics. The field has not made a concerted effort to divest our concepts and investigative tools from this fraught history, and as a result, an ableist investigative lens has persisted in present-day evolutionary research, limiting the scope of research and harming the ability to communicate and synthesize knowledge about evolutionary processes. This failure to divest from our eugenicist and ableist history has harmed progress in evolutionary biology and allowed principles from evolutionary biology to continue to be weaponized against marginalized communities in the modern day. To rectify this problem, scholars in evolutionary research must come to terms with how the history of the field has influenced their investigations and work to establish a new framework for defining and investigating concepts such as selection and fitness.
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42
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Booker TR, Payseur BA, Tigano A. Background selection under evolving recombination rates. Proc Biol Sci 2022; 289:20220782. [PMID: 35730151 PMCID: PMC9233929 DOI: 10.1098/rspb.2022.0782] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Background selection (BGS), the effect that purifying selection exerts on sites linked to deleterious alleles, is expected to be ubiquitous across eukaryotic genomes. The effects of BGS reflect the interplay of the rates and fitness effects of deleterious mutations with recombination. A fundamental assumption of BGS models is that recombination rates are invariant over time. However, in some lineages, recombination rates evolve rapidly, violating this central assumption. Here, we investigate how recombination rate evolution affects genetic variation under BGS. We show that recombination rate evolution modifies the effects of BGS in a manner similar to a localized change in the effective population size, potentially leading to underestimation or overestimation of the genome-wide effects of selection. Furthermore, we find evidence that recombination rate evolution in the ancestors of modern house mice may have impacted inferences of the genome-wide effects of selection in that species.
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Affiliation(s)
- Tom R. Booker
- Department of Zoology, University of British Columbia, Vancouver Campus, Vancouver, BC, Canada
| | - Bret A. Payseur
- Laboratory of Genetics, University of Wisconsin - Madison, Madison, WI, USA
| | - Anna Tigano
- Department of Biology, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada
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43
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Johri P, Aquadro CF, Beaumont M, Charlesworth B, Excoffier L, Eyre-Walker A, Keightley PD, Lynch M, McVean G, Payseur BA, Pfeifer SP, Stephan W, Jensen JD. Recommendations for improving statistical inference in population genomics. PLoS Biol 2022; 20:e3001669. [PMID: 35639797 PMCID: PMC9154105 DOI: 10.1371/journal.pbio.3001669] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The field of population genomics has grown rapidly in response to the recent advent of affordable, large-scale sequencing technologies. As opposed to the situation during the majority of the 20th century, in which the development of theoretical and statistical population genetic insights outpaced the generation of data to which they could be applied, genomic data are now being produced at a far greater rate than they can be meaningfully analyzed and interpreted. With this wealth of data has come a tendency to focus on fitting specific (and often rather idiosyncratic) models to data, at the expense of a careful exploration of the range of possible underlying evolutionary processes. For example, the approach of directly investigating models of adaptive evolution in each newly sequenced population or species often neglects the fact that a thorough characterization of ubiquitous nonadaptive processes is a prerequisite for accurate inference. We here describe the perils of these tendencies, present our consensus views on current best practices in population genomic data analysis, and highlight areas of statistical inference and theory that are in need of further attention. Thereby, we argue for the importance of defining a biologically relevant baseline model tuned to the details of each new analysis, of skepticism and scrutiny in interpreting model fitting results, and of carefully defining addressable hypotheses and underlying uncertainties.
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Affiliation(s)
- Parul Johri
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Charles F. Aquadro
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Mark Beaumont
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Brian Charlesworth
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Laurent Excoffier
- Institute of Ecology and Evolution, University of Berne, Berne, Switzerland
| | - Adam Eyre-Walker
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Peter D. Keightley
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael Lynch
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Gil McVean
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Bret A. Payseur
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Susanne P. Pfeifer
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | | | - Jeffrey D. Jensen
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
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44
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Liang YY, Chen XY, Zhou BF, Mitchell-Olds T, Wang B. Globally Relaxed Selection and Local Adaptation in Boechera stricta. Genome Biol Evol 2022; 14:evac043. [PMID: 35349686 PMCID: PMC9011030 DOI: 10.1093/gbe/evac043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2022] [Indexed: 11/25/2022] Open
Abstract
The strength of selection varies among populations and across the genome, but the determinants of efficacy of selection remain unclear. In this study, we used whole-genome sequencing data from 467 Boechera stricta accessions to quantify the strength of selection and characterize the pattern of local adaptation. We found low genetic diversity on 0-fold degenerate sites and conserved non-coding sites, indicating functional constraints on these regions. The estimated distribution of fitness effects and the proportion of fixed substitutions suggest relaxed negative and positive selection in B. stricta. Among the four population groups, the NOR and WES groups have smaller effective population size (Ne), higher proportions of effectively neutral sites, and lower rates of adaptive evolution compared with UTA and COL groups, reflecting the effect of Ne on the efficacy of natural selection. We also found weaker selection on GC-biased sites compared with GC-conservative (unbiased) sites, suggested that GC-biased gene conversion has affected the strength of selection in B. stricta. We found mixed evidence for the role of the recombination rate on the efficacy of selection. The positive and negative selection was stronger in high-recombination regions compared with low-recombination regions in COL but not in other groups. By scanning the genome, we found different subsets of selected genes suggesting differential adaptation among B. stricta groups. These results show that differences in effective population size, nucleotide composition, and recombination rate are important determinants of the efficacy of selection. This study enriches our understanding of the roles of natural selection and local adaptation in shaping genomic variation.
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Affiliation(s)
- Yi-Ye Liang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences,
Guangzhou, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Xue-Yan Chen
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences,
Guangzhou, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Biao-Feng Zhou
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences,
Guangzhou, China
- University of the Chinese Academy of Sciences, Beijing, China
| | | | - Baosheng Wang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences,
Guangzhou, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
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45
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Simha A, Hoz CPDL, Carley L. Moving beyond the “diversity paradox”: the limitations of competition-based frameworks in understanding species diversity. Am Nat 2022; 200:89-100. [DOI: 10.1086/720002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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46
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Fields PD, McTaggart S, Reisser CMO, Haag C, Palmer WH, Little TJ, Ebert D, Obbard DJ. Population-genomic analysis identifies a low rate of global adaptive fixation in the proteins of the cyclical parthenogen Daphnia magna. Mol Biol Evol 2022; 39:6542319. [PMID: 35244177 PMCID: PMC8963301 DOI: 10.1093/molbev/msac048] [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: 11/26/2022] Open
Abstract
Daphnia are well-established ecological and evolutionary models, and the interaction between D. magna and its microparasites is widely considered a paragon of the host-parasite coevolutionary process. Like other well-studied arthropods such as Drosophila melanogaster and Anopheles gambiae, D. magna is a small, widespread, and abundant species that is therefore expected to display a large long-term population size and high rates of adaptive protein evolution. However, unlike these other species, D. magna is cyclically asexual and lives in a highly structured environment (ponds and lakes) with moderate levels of dispersal, both of which are predicted to impact upon long-term effective population size and adaptive protein evolution. To investigate patterns of adaptive protein fixation, we produced the complete coding genomes of 36 D. magna clones sampled from across the European range (Western Palaearctic), along with draft sequences for the close relatives D. similis and D. lumholtzi, used as outgroups. We analyzed genome-wide patterns of adaptive fixation, with a particular focus on genes that have an a priori expectation of high rates, such as those likely to mediate immune responses, RNA interference against viruses and transposable elements, and those with a strongly male-biased expression pattern. We find that, as expected, D. magna displays high levels of diversity and that this is highly structured among populations. However, compared with Drosophila, we find that D. magna proteins appear to have a high proportion of weakly deleterious variants and do not show evidence of pervasive adaptive fixation across its entire range. This is true of the genome as a whole, and also of putative ‘arms race’ genes that often show elevated levels of adaptive substitution in other species. In addition to the likely impact of extensive, and previously documented, local adaptation, we speculate that these findings may reflect reduced efficacy of selection associated with cyclical asexual reproduction.
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Affiliation(s)
- Peter D Fields
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, Basel, CH-4051, Switzerland
| | - Seanna McTaggart
- Institute of Evolutionary Biology; School of Biological Sciences University of Edinburgh, Edinburgh, EH9 3JT, United Kingdom
| | - Céline M O Reisser
- Centre d'Ecologie Fonctionnelle et Evolutive CEFE UMR 5175, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, campus CNRS, 1919, route de Mende, 34293 Montpellier Cedex 5, France.,MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Christoph Haag
- Centre d'Ecologie Fonctionnelle et Evolutive CEFE UMR 5175, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, campus CNRS, 1919, route de Mende, 34293 Montpellier Cedex 5, France
| | - William H Palmer
- Institute of Evolutionary Biology; School of Biological Sciences University of Edinburgh, Edinburgh, EH9 3JT, United Kingdom
| | - Tom J Little
- Institute of Evolutionary Biology; School of Biological Sciences University of Edinburgh, Edinburgh, EH9 3JT, United Kingdom
| | - Dieter Ebert
- University of Basel, Department of Environmental Sciences, Zoology, Vesalgasse 1, Basel, CH-4051, Switzerland
| | - Darren J Obbard
- Institute of Evolutionary Biology; School of Biological Sciences University of Edinburgh, Edinburgh, EH9 3JT, United Kingdom
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47
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Palazzo AF, Kejiou NS. Non-Darwinian Molecular Biology. Front Genet 2022; 13:831068. [PMID: 35251134 PMCID: PMC8888898 DOI: 10.3389/fgene.2022.831068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/24/2022] [Indexed: 12/14/2022] Open
Abstract
With the discovery of the double helical structure of DNA, a shift occurred in how biologists investigated questions surrounding cellular processes, such as protein synthesis. Instead of viewing biological activity through the lens of chemical reactions, this new field used biological information to gain a new profound view of how biological systems work. Molecular biologists asked new types of questions that would have been inconceivable to the older generation of researchers, such as how cellular machineries convert inherited biological information into functional molecules like proteins. This new focus on biological information also gave molecular biologists a way to link their findings to concepts developed by genetics and the modern synthesis. However, by the late 1960s this all changed. Elevated rates of mutation, unsustainable genetic loads, and high levels of variation in populations, challenged Darwinian evolution, a central tenant of the modern synthesis, where adaptation was the main driver of evolutionary change. Building on these findings, Motoo Kimura advanced the neutral theory of molecular evolution, which advocates that selection in multicellular eukaryotes is weak and that most genomic changes are neutral and due to random drift. This was further elaborated by Jack King and Thomas Jukes, in their paper “Non-Darwinian Evolution”, where they pointed out that the observed changes seen in proteins and the types of polymorphisms observed in populations only become understandable when we take into account biochemistry and Kimura’s new theory. Fifty years later, most molecular biologists remain unaware of these fundamental advances. Their adaptionist viewpoint fails to explain data collected from new powerful technologies which can detect exceedingly rare biochemical events. For example, high throughput sequencing routinely detects RNA transcripts being produced from almost the entire genome yet are present less than one copy per thousand cells and appear to lack any function. Molecular biologists must now reincorporate ideas from classical biochemistry and absorb modern concepts from molecular evolution, to craft a new lens through which they can evaluate the functionality of transcriptional units, and make sense of our messy, intricate, and complicated genome.
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48
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Savage PE, Passmore S, Chiba G, Currie TE, Suzuki H, Atkinson QD. Sequence alignment of folk song melodies reveals cross-cultural regularities of musical evolution. Curr Biol 2022; 32:1395-1402.e8. [PMID: 35120658 DOI: 10.1016/j.cub.2022.01.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 09/07/2021] [Accepted: 01/13/2022] [Indexed: 01/18/2023]
Abstract
Culture evolves,1-5 but the existence of cross-culturally general regularities of cultural evolution is debated.6-8 As a diverse but universal cultural phenomenon, music provides a novel domain to test for the existence of such regularities.9-12 Folk song melodies can be thought of as culturally transmitted sequences of notes that change over time under the influence of cognitive and acoustic/physical constraints.9-15 Modeling melodies as evolving sequences constructed from an "alphabet" of 12 scale degrees16 allows us to quantitatively test for the presence of cross-cultural regularities using a sample of 10,062 melodies from musically divergent Japanese and English (British/American) folk song traditions.17,18 Our analysis identifies 328 pairs of highly related melodies, finding that note changes are more likely when they have smaller impacts on a song's melody. Specifically, (1) notes with stronger rhythmic functions are less likely to change, and (2) note substitutions are most likely between neighboring notes. We also find that note insertions/deletions ("indels") are more common than note substitutions, unlike genetic evolution where the reverse is true. Our results are consistent across English and Japanese samples despite major differences in their scales and tonal systems. These findings demonstrate that even a creative art form such as music is subject to evolutionary constraints analogous to those governing the evolution of genes, languages, and other domains of culture.
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Affiliation(s)
- Patrick E Savage
- Faculty of Environment and Information Studies, Keio University, Shonan Fujisawa Campus, Endo, Fujisawa, Kanagawa 252-0882, Japan; School of Anthropology and Museum Archaeology, University of Oxford, Banbury Road, Oxford OX2 6PE, UK; Department of Musicology, Tokyo University of the Arts, Uenokoen, Taito, Tokyo 110-8714, Japan.
| | - Sam Passmore
- Faculty of Environment and Information Studies, Keio University, Shonan Fujisawa Campus, Endo, Fujisawa, Kanagawa 252-0882, Japan
| | - Gakuto Chiba
- Faculty of Environment and Information Studies, Keio University, Shonan Fujisawa Campus, Endo, Fujisawa, Kanagawa 252-0882, Japan
| | - Thomas E Currie
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Haruo Suzuki
- Faculty of Environment and Information Studies, Keio University, Shonan Fujisawa Campus, Endo, Fujisawa, Kanagawa 252-0882, Japan
| | - Quentin D Atkinson
- School of Psychology, University of Auckland, Private Bag 92019, Symonds Street, Auckland 1010, New Zealand
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Chen J, Bataillon T, Glémin S, Lascoux M. What does the distribution of fitness effects of new mutations reflect? Insights from plants. THE NEW PHYTOLOGIST 2022; 233:1613-1619. [PMID: 34704271 DOI: 10.1111/nph.17826] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
The distribution of fitness effects (DFE) of new mutations plays a central role in molecular evolution. It is therefore crucial to be able to estimate it accurately from genomic data and to understand the factors that shape it. After a rapid overview of available methods to characterize the fitness effects of mutations, we review what is known on the factors affecting them in plants. Available data indicate that life history traits (e.g. mating system and longevity) have a major effect on the DFE. By contrast, the impact of demography within species appears to be more limited. These results remain to be confirmed, and methods to estimate the joint evolution of demography, life history traits, and the DFE need to be developed.
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Affiliation(s)
- Jun Chen
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Thomas Bataillon
- Bioinformatics Research Centre, Aarhus University, C.F. Möllers Allé 8, Aarhus C, DK-8000, Denmark
| | - Sylvain Glémin
- Centre National de la Recherche Scientifique (CNRS), ECOBIO (Ecosystèmes, Biodiversité, Evolution) - Unité Mixte de Recherche (UMR) 6553, Université de Rennes, Rennes, F-35000, France
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, 75236, Sweden
| | - Martin Lascoux
- Program in Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, 75236, Sweden
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50
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Boitard S, Arredondo A, Chikhi L, Mazet O. Heterogeneity in effective size across the genome: effects on the inverse instantaneous coalescence rate (IICR) and implications for demographic inference under linked selection. Genetics 2022; 220:6512058. [PMID: 35100421 PMCID: PMC8893248 DOI: 10.1093/genetics/iyac008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/01/2022] [Indexed: 01/22/2023] Open
Abstract
The relative contribution of selection and neutrality in shaping species genetic diversity is one of the most central and controversial questions in evolutionary theory. Genomic data provide growing evidence that linked selection, i.e. the modification of genetic diversity at neutral sites through linkage with selected sites, might be pervasive over the genome. Several studies proposed that linked selection could be modeled as first approximation by a local reduction (e.g. purifying selection, selective sweeps) or increase (e.g. balancing selection) of effective population size (Ne). At the genome-wide scale, this leads to variations of Ne from one region to another, reflecting the heterogeneity of selective constraints and recombination rates between regions. We investigate here the consequences of such genomic variations of Ne on the genome-wide distribution of coalescence times. The underlying motivation concerns the impact of linked selection on demographic inference, because the distribution of coalescence times is at the heart of several important demographic inference approaches. Using the concept of inverse instantaneous coalescence rate, we demonstrate that in a panmictic population, linked selection always results in a spurious apparent decrease of Ne along time. Balancing selection has a particularly large effect, even when it concerns a very small part of the genome. We also study more general models including genuine population size changes, population structure or transient selection and find that the effect of linked selection can be significantly reduced by that of population structure. The models and conclusions presented here are also relevant to the study of other biological processes generating apparent variations of Ne along the genome.
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Affiliation(s)
- Simon Boitard
- CBGP, Université de Montpellier, CIRAD, INRAE, Institut Agro, IRD, Montferrier-sur-Lez 34988, France
- Corresponding author: Université de Montpellier, CIRAD, INRAE, Institut Agro, IRD, 755 Avenue du Campus Agropolis, CS 30016, Montferrier-sur-Lez 34988, France.
| | - Armando Arredondo
- Institut National des Sciences Appliquées, Institut de Mathématiques de Toulouse, Université de Toulouse,Toulouse 31062, France
| | - Lounès Chikhi
- Instituto Gulbenkian de Ciência, Oeiras P-2780-156, Portugal
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, UPS, Université de Toulouse Midi-Pyrénées, Toulouse 31062, France
| | - Olivier Mazet
- Institut National des Sciences Appliquées, Institut de Mathématiques de Toulouse, Université de Toulouse,Toulouse 31062, France
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