scholarly journals Minimal-assumption inference from population-genomic data

2016 ◽  
Author(s):  
Daniel B. Weissman ◽  
Oskar Hallatschek
Keyword(s):  
Evolutionary History ◽  
Simulated Data ◽  
Effective Population ◽  
Minimal Assumption ◽  
Genome Data ◽  
Human Genomes ◽  
Single Genome ◽  
Linkage Information ◽  
Time Histories ◽  
History Of

AbstractSamples of multiple complete genome sequences contain vast amounts of information about the evolutionary history of populations, much of it in the associations among polymorphisms at different loci. Current methods that take advantage of this linkage information rely on models of recombination and coalescence, limiting the sample sizes and populations that they can analyze. We introduce a method, Minimal-Assumption Genomic Inference of Coalescence (MAGIC), that reconstructs key features of the evolutionary history, including the distribution of coalescence times, by integrating information across genomic length scales without using an explicit model of recombination, demography or selection. Using simulated data, we show that MAGIC’s performance is comparable to PSMC’ on single diploid samples generated with standard coalescent and recombination models. More importantly, MAGIC can also analyze arbitrarily large samples and is robust to changes in the coalescent and recombination processes. Using MAGIC, we show that the inferred coalescence time histories of samples of multiple human genomes exhibit inconsistencies with a description in terms of an effective population size based on single-genome data.

scholarly journals Minimal-assumption inference from population-genomic data

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Daniel B Weissman ◽  
Oskar Hallatschek
Keyword(s):  
Evolutionary History ◽  
Simulated Data ◽  
Large Samples ◽  
Minimal Assumption ◽  
Population Genomic ◽  
Human Genomes ◽  
History Of ◽  
Or Gene ◽  
Linked Selection ◽  
Genomic Length

Samples of multiple complete genome sequences contain vast amounts of information about the evolutionary history of populations, much of it in the associations among polymorphisms at different loci. We introduce a method, Minimal-Assumption Genomic Inference of Coalescence (MAGIC), that reconstructs key features of the evolutionary history, including the distribution of coalescence times, by integrating information across genomic length scales without using an explicit model of coalescence or recombination, allowing it to analyze arbitrarily large samples without phasing while making no assumptions about ancestral structure, linked selection, or gene conversion. Using simulated data, we show that the performance of MAGIC is comparable to that of PSMC’ even on single diploid samples generated with standard coalescent and recombination models. Applying MAGIC to a sample of human genomes reveals evidence of non-demographic factors driving coalescence.

scholarly journals RIP mutated ITS genes in populations of Ophiocordyceps sinensis and their implications for molecular systematics

IMA Fungus ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi Li ◽  
Lan Jiang ◽  
Ke Wang ◽  
Hai-Jun Wu ◽  
Rui-Heng Yang ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Large Scale ◽  
Its Region ◽  
Wide Distribution ◽  
Specific Primers ◽  
Ophiocordyceps Sinensis ◽  
Single Genome ◽  
History Of ◽  
Geographic Populations ◽  
Internal Transcribed Spacer Sequences

Abstract Different hypotheses have been proposed to interpret the observed unusual ITS (internal transcribed spacer) sequences in Ophiocordyceps sinensis. The coexistence of diverged ITS paralogs in a single genome was previously shown by amplifying the ITS region from mono-ascospore isolates using specific primers designed for different ITS paralog groups. Among those paralogs, are AT-biased ITS sequences which were hypothesized to result from repeat-induced point mutation (RIP). This is a process that detects and mutates repetitive DNA and frequently leads to epigenetic silencing, and these mutations have been interpreted as pseudogenes. Here we investigate the occurrence and frequency of ITS pseudogenes in populations of O. sinensis using large-scale sampling, and discusses the implications of ITS pseudogenes for fungal phylogenetic and evolutionary studies. Our results demonstrate a wide distribution of ITS pseudogenes amongst different geographic populations, and indicate how ITS pseudogenes can contribute to the reconstruction of the evolutionary history of the species.

scholarly journals An insight into the evolutionary history of Indonesian cattle assessed by whole genome data analysis

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241038
Author(s):  
Pita Sudrajad ◽  
Subiharta Subiharta ◽  
Yudi Adinata ◽  
Af’idatul Lathifah ◽  
Jun Heon Lee ◽  
...  
Keyword(s):  
Demographic History ◽  
Bos Indicus ◽  
Molecular Evidence ◽  
Effective Population ◽  
Genome Data ◽  
Bos Javanicus ◽  
History Of ◽  
Genome Data Analysis ◽  
Almost All ◽  
Insight Into

The domestication of Indonesian cattle was investigated through a study of their genetic diversity, up to the genome level. Little documentation exists regarding the history of domestication of Indonesian cattle and questions remain despite a growing body of molecular evidence. In this study, we genotyped seven Indonesian cattle breeds using an Illumina BovineSNP50 Bead Chip to provide insight into their domestication and demographic history in a worldwide population context. Our analyses indicated the presence of hybrid cattle, with Bos javanicus and Bos indicus ancestries being most prevalent, as well as purebred cattle. We revealed that all the breeds were interconnected through several migration events. However, their demographic status varied widely. Although almost all the Indonesian cattle had an effective population size higher than the minimum level required to ensure breed fitness, efforts are still needed to maintain their genetic variability and purity.

scholarly journals Approximating the coalescent under facultative sex

2019 ◽  
Author(s):  
Matthew Hartfield
Keyword(s):  
Population Size ◽  
Evolutionary History ◽  
Sampling Strategies ◽  
Effective Population ◽  
Sexual Species ◽  
History Of ◽  
Mitotic Gene Conversion ◽  
Evolutionary Consequences ◽  
Insight Into ◽  
Coalescent Time

AbstractGenome studies of facultative sexual species, which can either reproduce sexually or asexually, are providing insight into the evolutionary consequences of mixed reproductive modes. It is currently unclear to what extent the evolutionary history of facultative sexuals’ genomes can be approximated by the standard coalescent, and if a coalescent effective population size Ne exists. Here, I determine if and when these approximations can be made. When sex is frequent (occurring at a frequency much greater than 1/N per reproduction per generation, for N the actual population size), the underlying genealogy can be approximated by the standard coalescent, with a coalescent Ne ≈ N. When sex is very rare (at frequency much lower than 1/N), approximations for the pairwise coalescent time can be obtained, which is strongly influenced by the frequencies of sex and mitotic gene conversion, rather than N. However, these terms do not translate into a coalescent Ne. These results are used to discuss the best sampling strategies for investigating the evolutionary history of facultative sexual species.

Exploiting new genome data and Internet resources for the phylogenetic analysis of proteases, substrates and inhibitors

2007 ◽  
Vol 35 (3) ◽  
pp. 599-603 ◽  
Author(s):  
C. Southan
Keyword(s):  
Phylogenetic Analysis ◽  
Evolutionary History ◽  
Protease Gene ◽  
Endogenous Inhibitor ◽  
Genome Data ◽  
Catalytic Function ◽  
Internet Resources ◽  
Multiple Alignments ◽  
Interaction Partners ◽  
History Of

Multiple alignments and phylogenetic tree constructions are established techniques for examining the evolutionary history of protease sequences in organisms such as humans, mice, fruitflies, nematode worms and yeast. They also facilitate the mapping of those conserved positions that are important for structure and catalytic function. However, the continued increase in completed or draft genomes offers new opportunities for examining protease evolution across a broader (e.g. more mammals) and deeper (e.g. more invertebrates) phylogenetic range. In addition, the improving annotation not only of proteases, but also of their substrates, interaction partners in proteolytic complexes and endogenous inhibitor proteins now means that aspects of co-evolution can be addressed. The increasing phylogenetic coverage is also important for resolving orthology issues that arise from protease gene duplication or loss in different lineages. Selected sequences will be used to exemplify the utility of Internet resources and present results for these types of analysis.

scholarly journals A Comprehensive Comparative Phylogenomics and Demographic Evolutionary History of the SARS-CoV-2

2020 ◽  
Author(s):  
Özgül Doğan ◽  
Ertan Mahir Korkmaz ◽  
Mahir Budak ◽  
Battal Çıplak ◽  
Hasan Hüseyin Başıbüyük
Keyword(s):  
Evolutionary History ◽  
Demographic History ◽  
Amino Acid Sequences ◽  
Neutral Evolution ◽  
Genomic Evolution ◽  
Evolutionary Patterns ◽  
Network Analyses ◽  
Genome Data ◽  
History Of

A new form of beta coronavirus called severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) causing a recent pandemic outbreak possesses a linear positive ss-RNA genome with a length of 29,903 nt. Here, the genomes of SARS-CoV-2 from 821 samples were characterised for its better understanding of the genomic and evolutionary patterns. The phylogeny of SARS-CoV-2 was reconstructed using concatenated dataset consisting of all peptide encoding sequences under Bayesian Inference (BI) and Maximum Likelihood (ML) approaches. Comparison of all peptide encoding sequences reveals high divergence of amino acid sequences proportional to divergence of nucleotides, indicating that the viral genomic evolution has not been strictly neutral. The most part of the genome was under neutral evolution, however, the specific sites for peptide encoding sequences were evolved under positive selection. As well as providing reliable evidence on transmission routes of the SARS-CoV-2 outbreak, the phylogenetics and network analyses suggest the sample reported from Guangdong province is likely ancestor of the pandemic virus form. The overall substitution rate of SARS-CoV-2 genome was estimated to be 1.65 x 10-3 per site per year, falling within the range for previously reported RNA viruses. Median estimation of tMRCA from Bayesian coalescent analyses corresponds to 10 September 2019. The exponential growth rate (r), doubling time (Td) and R0 were estimated to be 47.43 per year, 5.39 days and 2.72, respectively. These findings convincingly emphasise that the use of more comprehensive genome data improves robustness and also enhances understanding of the demographic history of the outbreak.

scholarly journals Ancient mitochondrial genomes from Chinese cave hyenas provide insights into the evolutionary history of the genus Crocuta

2021 ◽  
Vol 288 (1943) ◽  
pp. 20202934
Author(s):  
Jiaming Hu ◽  
Michael V. Westbury ◽  
Junxia Yuan ◽  
Zhen Zhang ◽  
Shungang Chen ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Mitochondrial Genomes ◽  
Effective Population ◽  
Wide Range ◽  
Two Samples ◽  
Spotted Hyenas ◽  
History Of ◽  
Close Relatives

Cave hyenas (genus Crocuta ) are extinct bone-cracking carnivores from the family Hyaenidae and are generally split into two taxa that correspond to a European/Eurasian and an (East) Asian lineage. They are close relatives of the extant African spotted hyenas, the only extant member of the genus Crocuta . Cave hyenas inhabited a wide range across Eurasia during the Pleistocene, but became extinct at the end of the Late Pleistocene. Using genetic and genomic datasets, previous studies have proposed different scenarios about the evolutionary history of Crocuta. However, causes of the extinction of cave hyenas are widely speculative and samples from China are severely understudied. In this study, we assembled near-complete mitochondrial genomes from two cave hyenas from northeastern China dating to 20 240 and 20 253 calBP, representing the youngest directly dated fossils of Crocuta in Asia. Phylogenetic analyses suggest a monophyletic clade of these two samples within a deeply diverging mitochondrial haplogroup of Crocuta . Bayesian analyses suggest that the split of this Asian cave hyena mitochondrial lineage from their European and African relatives occurred approximately 1.85 Ma (95% CI 1.62–2.09 Ma), which is broadly concordant with the earliest Eurasian Crocuta fossil dating to approximately 2 Ma. Comparisons of mean genetic distance indicate that cave hyenas harboured higher genetic diversity than extant spotted hyenas, brown hyenas and aardwolves, but this is probably at least partially due to the fact that their mitochondrial lineages do not represent a monophyletic group, although this is also true for extant spotted hyenas. Moreover, the joint female effective population size of Crocuta (both cave hyenas and extant spotted hyenas) has sustained two declines during the Late Pleistocene. Combining this mitochondrial phylogeny, previous nuclear findings and fossil records, we discuss the possible relationship of fossil Crocuta in China and the extinction of cave hyenas.

scholarly journals Further resolution of the house mouse (Mus musculus) phylogeny by integration over isolation-with-migration histories

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Megan Phifer-Rixey ◽  
Bettina Harr ◽  
Jody Hey
Keyword(s):  
Gene Flow ◽  
Mus Musculus ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
House Mice ◽  
Mus Musculus Domesticus ◽  
Effective Population ◽  
Isolation With Migration ◽  
Mus Musculus Musculus ◽  
History Of

Abstract Background The three main subspecies of house mice, Mus musculus castaneus, Mus musculus domesticus, and Mus musculus musculus, are estimated to have diverged ~ 350-500KYA. Resolution of the details of their evolutionary history is complicated by their relatively recent divergence, ongoing gene flow among the subspecies, and complex demographic histories. Previous studies have been limited to some extent by the number of loci surveyed and/or by the scope of the method used. Here, we apply a method (IMa3) that provides an estimate of a population phylogeny while allowing for complex histories of gene exchange. Results Results strongly support a topology with M. m. domesticus as sister to M. m. castaneus and M. m. musculus. In addition, we find evidence of gene flow between all pairs of subspecies, but that gene flow is most restricted from M. m. musculus into M. m. domesticus. Estimates of other key parameters are dependent on assumptions regarding generation time and mutation rate in house mice. Nevertheless, our results support previous findings that the effective population size, Ne, of M. m. castaneus is larger than that of the other two subspecies, that the three subspecies began diverging ~ 130 - 420KYA, and that the time between divergence events was short. Conclusions Joint demographic and phylogenetic analyses of genomic data provide a clearer picture of the history of divergence in house mice.

scholarly journals SRGAP2 and the gradual evolution of the modern human language faculty

2017 ◽  
Author(s):  
Pedro Tiago Martins ◽  
Maties Marí ◽  
Cedric Boeckx
Keyword(s):  
Axon Guidance ◽  
Evolutionary History ◽  
Vocal Learning ◽  
Modern Human ◽  
Language Faculty ◽  
Molecular Pathway ◽  
Human Genomes ◽  
Gradual Evolution ◽  
Anatomically Modern Humans ◽  
History Of

AbstractIn this paper we examine a new source of evidence that draws on data from archaic human genomes to support the hypothesis that vocal learning in Homo preceded the emergence of Anatomically Modern Humans. We build our claim on the evolutionary history of the SLITROBO GTPase 2 gene (SRGAP2). The SLIT-ROBO molecular pathway has been shown to have an important role in the context of vocal learning. Though the relevance of the SRGAP2 gene duplication in the emergence of some aspect of language has not gone completely unnoticed, recent results now allow us to articulate a mechanistic hypothesis of its role in the context of axon guidance. Specifically, SRGAP2C, a duplication of SRGAP2 crucially also found in Neanderthals and Denisovans, but not in extant mammals, inhibits the ancestral SRGAP2A, which in turn modulates the axon guidance function of the SLIT-ROBO molecular pathway. This, we claim, could have contributed to the establishment of the critical cortico-laryngeal connection of the vocal learning circuit. Our conclusions support the idea that complex vocal learning could already have been part of the arsenal of some of our extinct ancestors.

scholarly journals The evolutionary history of Neanderthal and Denisovan Y chromosomes

Science ◽  
2020 ◽  
Vol 369 (6511) ◽  
pp. 1653-1656 ◽  
Author(s):  
Martin Petr ◽  
Mateja Hajdinjak ◽  
Qiaomei Fu ◽  
Elena Essel ◽  
Hélène Rougier ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Evolutionary History ◽  
Genetic Load ◽  
Modern Human ◽  
Gene Pools ◽  
Chromosomal Gene ◽  
Human History ◽  
Effective Population ◽  
Y Chromosomes ◽  
History Of

Ancient DNA has provided new insights into many aspects of human history. However, we lack comprehensive studies of the Y chromosomes of Denisovans and Neanderthals because the majority of specimens that have been sequenced to sufficient coverage are female. Sequencing Y chromosomes from two Denisovans and three Neanderthals shows that the Y chromosomes of Denisovans split around 700 thousand years ago from a lineage shared by Neanderthals and modern human Y chromosomes, which diverged from each other around 370 thousand years ago. The phylogenetic relationships of archaic and modern human Y chromosomes differ from the population relationships inferred from the autosomal genomes and mirror mitochondrial DNA phylogenies, indicating replacement of both the mitochondrial and Y chromosomal gene pools in late Neanderthals. This replacement is plausible if the low effective population size of Neanderthals resulted in an increased genetic load in Neanderthals relative to modern humans.

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