scholarly journals Inference of horizontal genetic transfer from molecular data: an approach using the bootstrap.

Genetics ◽  
1992 ◽  
Vol 131 (3) ◽  
pp. 753-760 ◽  
Author(s):  
J G Lawrence ◽  
D L Hartl
Keyword(s):  
Horizontal Transfer ◽  
Phylogenetic Trees ◽  
Fragment Length Polymorphism ◽  
Genetic Material ◽  
Molecular Data ◽  
Data Sets ◽  
Similarity Coefficients ◽  
Genetic Transfer ◽  
Statistical Framework ◽  
Partial Data

Abstract Inconsistencies in taxonomic relationships implicit in different sets of nucleic acid sequences potentially result from horizontal transfer of genetic material between genomes. A nonparametric method is proposed to determine whether such inconsistencies are statistically significant. A similarity coefficient is calculated from ranked pairwise identities and evaluated against a distribution of similarity coefficients generated from resampled data. Subsequent analyses of partial data sets, obtained by the elimination of individual taxa, identify particular taxa to which the significance may be attributed, and can sometimes help in distinguishing horizontal genetic transfer from inconsistencies due to convergent evolution or variation in evolutionary rate. The method was successfully applied to data sets that were not found to be significantly different with existing methods that use comparisons of phylogenetic trees. The new statistical framework is also applicable to the inference of horizontal transfer from restriction fragment length polymorphism distributions and protein sequences.

scholarly journals Is there a need for accepting paraphyletic taxa? A case study in the Sardinian endemic Cymbalaria muelleri (Plantaginaceae)

2019 ◽  
Vol 191 (3) ◽  
pp. 325-338 ◽  
Author(s):  
Pau Carnicero ◽  
Peter Schönswetter ◽  
Núria Garcia-Jacas ◽  
Mercè Galbany-Casals
Keyword(s):  
Genome Size ◽  
Phylogenetic Trees ◽  
Fragment Length Polymorphism ◽  
Habitat Preferences ◽  
Molecular Data ◽  
Disjunct Distribution ◽  
Morphological Differences ◽  
A New Species ◽  
The Mediterranean Basin

Abstract Evolution does not always result in dichotomous phylogenetic trees. For instance, in anacladogenetic speciation, where a new species originates by budding, the ancestral taxon is often initially paraphyletic. Here we study Cymbalaria muelleri (Plantaginaceae), a chasmophytic species endemic to Sardinia, a major island in the Mediterranean Basin. Its distribution range is divided into two well-delimited geographical groups with some morphological differences. Using a combination of morphology, molecular data (amplified fragment length polymorphism fingerprinting) and relative genome size, we found that the two geographical groups should be considered two separate taxa, which split through anacladogenesis. Accordingly, we formally describe the new paraphyletic subspecies C. muelleri subsp. villosa as the ancestor, from which C. muelleri subsp. muelleri originated by budding. Morphological analyses support the differentiation of the two subspecies, and there are strong diagnostic characters to differentiate them. In addition to morphology and genetics, slightly divergent habitat preferences and the disjunct distribution of the two subspecies also support the recognition of two taxa. Genome size data obtained for the two subspecies are consistent with the previously established hexaploidy of C. muelleri.

Integration of morphological and molecular data sets in estimating fungal phytogenies

1995 ◽  
Vol 73 (S1) ◽  
pp. 649-659 ◽  
Author(s):  
François Lutzoni ◽  
Rytas Vilgalys
Keyword(s):  
Phylogenetic Trees ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Molecular Data ◽  
Morphological Data ◽  
Homogeneity Test ◽  
Data Sets ◽  
Data Set ◽  
Sampling Statistics ◽  
Combined Data

To provide a clearer picture of fungal species relationships, increased efforts are being made to include both molecular and morphological data sets in phylogenetic studies. This general practice in systematics has raised many unresolved questions and controversies regarding how to best integrate the phylogenetic information revealed by morphological and molecular characters. This is because phylogenetic trees derived using different data sets are rarely identical. Such discrepancies can be due to sampling error, to the use of an inappropriate evolutionary model for a given data set, or to different phylogenetic histories between the organisms and the molecule. Methods have been developed recently to test for heterogeneity among data sets, although none of these methods have been subjected to simulation studies. In this paper we compare three tests: a protocol described by Rodrigo et al., an adapted version of Faith's T-PTP test, and Kishino and Hasegawa's likelihood test. These tests were empirically compared using seven lichenized and nonlichenized Omphalina species and the related species Arrhenia lobata (Basidiomycota, Agaricales) for which nrDNA large subunit sequences and morphological data were gathered. The results of these three tests were inconsistent, Rodrigo's test being the only one suggesting that the two data sets could be combined. One of the three most parsimonious trees obtained from the combined data set with eight species is totally congruent with the relationships among the same eight species in an analysis restricted to the same portion of the nrDNA large subunit but extended to 26 species of Omphalina and related genera. Therefore, the results from phylogenetic analyses of this large molecular data set converged on one of the three most parsimonious topologies generated by the combined data set analysis. This topology was not recovered from either data set when analysed separately. This suggests that Rodrigo's homogeneity test might be better suited than the two other tests for determining if trees obtained from different data sets are sampling statistics of the same phylogenetic history. Key words: data sets heterogeneity, homogeneity test, lichen phylogeny, Omphalina, ribosomal DNA.

scholarly journals Aminoacyl-tRNA Synthetases, the Genetic Code, and the Evolutionary Process

2000 ◽  
Vol 64 (1) ◽  
pp. 202-236 ◽  
Author(s):  
Carl R. Woese ◽  
Gary J. Olsen ◽  
Michael Ibba ◽  
Dieter Söll
Keyword(s):  
Genetic Code ◽  
Phylogenetic Trees ◽  
Genetic Material ◽  
Evolutionary Process ◽  
Group Iv ◽  
Evolutionary Relationships ◽  
Evolutionary Stage ◽  
Trna Synthetases ◽  
Aminoacyl Trna Synthetases ◽  
The Individual

SUMMARY The aminoacyl-tRNA synthetases (AARSs) and their relationship to the genetic code are examined from the evolutionary perspective. Despite a loose correlation between codon assignments and AARS evolutionary relationships, the code is far too highly structured to have been ordered merely through the evolutionary wanderings of these enzymes. Nevertheless, the AARSs are very informative about the evolutionary process. Examination of the phylogenetic trees for each of the AARSs reveals the following. (i) Their evolutionary relationships mostly conform to established organismal phylogeny: a strong distinction exists between bacterial- and archaeal-type AARSs. (ii) Although the evolutionary profiles of the individual AARSs might be expected to be similar in general respects, they are not. It is argued that these differences in profiles reflect the stages in the evolutionary process when the taxonomic distributions of the individual AARSs became fixed, not the nature of the individual enzymes. (iii) Horizontal transfer of AARS genes between Bacteria and Archaea is asymmetric: transfer of archaeal AARSs to the Bacteria is more prevalent than the reverse, which is seen only for the “gemini group.” (iv) The most far-ranging transfers of AARS genes have tended to occur in the distant evolutionary past, before or during formation of the primary organismal domains. These findings are also used to refine the theory that at the evolutionary stage represented by the root of the universal phylogenetic tree, cells were far more primitive than their modern counterparts and thus exchanged genetic material in far less restricted ways, in effect evolving in a communal sense.

scholarly journals Origin of the European avian-like swine influenza viruses

2014 ◽  
Vol 95 (11) ◽  
pp. 2372-2376 ◽  
Author(s):  
Andi Krumbholz ◽  
Jeannette Lange ◽  
Andreas Sauerbrei ◽  
Marco Groth ◽  
Matthias Platzer ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Swine Influenza ◽  
H1n1 Influenza ◽  
Molecular Data ◽  
Influenza Viruses ◽  
Time Resolved ◽  
Genotype Constellation ◽  
Tree Inference

The avian-like swine influenza viruses emerged in 1979 in Belgium and Germany. Thereafter, they spread through many European swine-producing countries, replaced the circulating classical swine H1N1 influenza viruses, and became endemic. Serological and subsequent molecular data indicated an avian source, but details remained obscure due to a lack of relevant avian influenza virus sequence data. Here, the origin of the European avian-like swine influenza viruses was analysed using a collection of 16 European swine H1N1 influenza viruses sampled in 1979–1981 in Germany, the Netherlands, Belgium, Italy and France, as well as several contemporaneous avian influenza viruses of various serotypes. The phylogenetic trees suggested a triple reassortant with a unique genotype constellation. Time-resolved maximum clade credibility trees indicated times to the most recent common ancestors of 34–46 years (before 2008) depending on the RNA segment and the method of tree inference.

Accuracy of estimated phylogenetic trees from molecular data

1983 ◽  
Vol 19 (2) ◽  
pp. 153-170 ◽  
Author(s):  
Masatoshi Nei ◽  
Fumio Tajima ◽  
Yoshio Tateno
Keyword(s):  
Phylogenetic Trees ◽  
Molecular Data

New species and findings of Pagastia Oliver (Diptera: Chironomidae: Diamesinae) from Central Asia, with DNA barcoding of known species of the genus

Zootaxa ◽  
2021 ◽  
Vol 4951 (3) ◽  
pp. 559-570
Author(s):  
EUGENYI A.  MAKARCHENKO ◽  
ALEXANDER A. SEMENCHENKO ◽  
DMITRY M. PALATOV
Keyword(s):  
New Species ◽  
Central Asia ◽  
Cytochrome Oxidase ◽  
Phylogenetic Trees ◽  
Morphological Characters ◽  
Molecular Data ◽  
Adult Males ◽  
Cytochrome Oxidase Subunit ◽  
Oxidase Subunit ◽  
Coi Sequences

Chironomids of the genus Pagastia Oliver (Diamesinae, Diamesini) from the mountains of Central Asia are revised using both morphological characters and molecular data. Illustrated descriptions of the adult male Pagastia (P.) caelestomontana sp. nov. from Kirgizstan and Tajikistan, P. (P.) hanseni sp. nov. from Tajikistan, and record of a finding apparently a new species P. (P.) aff. lanceolata (Tokunaga) from Tajikistan as well as an updated a key to the determination of the adult males of all known species of Pagastia are provided. A phylogenetic framework is reconstructed based on two mitochondrial genes cytochrome oxidase subunit I (COI) sequences of 34 samples belonging to 7 species of the genus Pagastia and cytochrome oxidase subunit II (COII) available for most samples. Phylogenetic trees of some known species of the genus Pagastia were reconstructed using the combined dataset and Bayesian inference (BI) and Maximum Likelihood (ML) methods. The interspecific K2P distances between seven Pagastia species including P. (P.) caelestomontana sp. nov., P. (P.) hanseni sp. nov. and undescribed P. (P.) aff. lanceolata (Tokunaga) are 6.3–13.2 which corresponding to species level. 

Accuracy of estimated phylogenetic trees from molecular data

1982 ◽  
Vol 18 (6) ◽  
pp. 387-404 ◽  
Author(s):  
Yoshio Tateno ◽  
Masatoshi Nei ◽  
Fumio Tajima
Keyword(s):  
Phylogenetic Trees ◽  
Molecular Data

scholarly journals Genome Sequence of Torulaspora microellipsoides CLIB 830T

2018 ◽  
Vol 6 (26) ◽  
Author(s):  
Virginie Galeote ◽  
Frédéric Bigey ◽  
Hugo Devillers ◽  
Raúl A. Ortiz-Merino ◽  
Sylvie Dequin ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genome Sequence ◽  
Horizontal Transfer ◽  
Reference Genome ◽  
Genetic Material ◽  
Ascomycetous Yeast ◽  
Content Type ◽  
Transfer Mechanisms

We report here the genome sequence of the ascomycetous yeast Torulaspora microellipsoides CLIB 830T. A reference genome for this species, which has been found as a donor of genetic material in wine strains of Saccharomyces cerevisiae, will undoubtedly give clues to our understanding of horizontal transfer mechanisms between species in the wine environment.

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