Author
Helga Ochoterena
Other affiliations: Ithaca College
Bio: Helga Ochoterena is an academic researcher from National Autonomous University of Mexico. The author has contributed to research in topics: Monophyly & Genus. The author has an hindex of 17, co-authored 52 publications receiving 3446 citations. Previous affiliations of Helga Ochoterena include Ithaca College.
Topics: Monophyly, Genus, Tribe (biology), Cinchonoideae, Phylogenetic tree
Papers published on a yearly basis
Papers
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TL;DR: Treatment of gaps varies widely from secondarily mapping gaps onto the tree inferred from base characters to uniformly applied method of treating gaps, which is lacking in sequence-based phyloge?
Abstract: In the analysis of sequence-based data matrices, the use of different methods of treating gaps has been demonstrated to in? fluence the resulting phylogenetic hypothe? ses (e.g., Eernisse and Kluge, 1993; Vogler and DeSalle, 1994; Simons and Mayden, 1997). Despite this influence, a well-justi? fied, uniformly applied method of treating gaps is lacking in sequence-based phyloge? netic studies. Treatment of gaps varies widely from secondarily mapping gaps onto the tree inferred from base characters
2,417 citations
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TL;DR: The potential phylogenetic information included in gap characters and the extent to which inclusion of gap characters alters the gene tree topology and branch support values are determined and the assertion that longer gaps are better phylogenetic characters than shorter gaps is tested.
Abstract: Phylogenetic analysis of nucleotide and amino acid sequences requires the alignment of homologous sequences. The alignment procedure often requires the insertion of gaps, putatively corresponding to insertion or deletion events, which can be coded as phylogenetic characters. As a general class of phylogenetic characters, gaps have variously been suggested to be reliable (e.g., Lloyd and Calder, 1991; Van Dijk et al., 1999) or unreliable (e.g., Golenberg et al., 1993; Ford et al., 1995). This difference in opinion, coupled with the lack of a well-supported method for the coding of gaps, has led to a diversity of approaches by which gaps have been treated in, or excluded from, tree searches (Gonzalez, 1996). In an earlier paper we presented two methods, termed simple and complex indel coding, in which all gaps (excluding leading and trailing gaps, which are generally artifacts) can be coded from aligned sequence-based matrices (Simmons and Ochoterena, 2000). Simple indel coding, which is used in this study, is implemented by coding all gaps that have different 5' or 3' termini as separate presence/absence characters. Whenever a gap is being coded and the region it spans is completely included within the span of another gap, those sequences having the longer gap (i.e., one that extends to or beyond both the 5' and 3' termini of the gap being coded) are scored as inapplicable for the gap character being coded. Some have suggested on theoretical and empirical grounds that longer gaps are better phylogenetic characters than shorter gaps. Lloyd and Calder (1991) argued that multiresidue gaps are reliable phylogenetic characters because indels are unlikely to be repeated in the exact same position with the same length and sequence (for insertions); indels of different lengths at the same position are recognized as separate events. Similarly, van Ham et al. (1994) suggested that, based on the relative levels of homoplasy in the intergenic spacer between trnL and trnF, gaps longer than two positions are reliable phylogenetic characters. In this paper we assess the relative levels of homoplasy of gap and base characters from a selection of 38 published sequence-based matrices. We determine the potential phylogenetic information included in gap characters and the extent to which inclusion of gap characters alters the gene tree topology and branch support values. We also test the assertion that longer gaps are better phylogenetic characters than shorter gaps.
214 citations
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TL;DR: A taxonomic backbone at the genus level is provided that reflects the current state of knowledge and accepts 749 genera for the Caryophyllales, a major lineage of flowering plants with approximately 12500 species in 39 families.
Abstract: The Caryophyllales constitute a major lineage of flowering plants with approximately 12500 species in 39 families. A taxonomic backbone at the genus level is provided that reflects the current state of knowledge and accepts 749 genera for the order. A detailed review of the literature of the past two decades shows that enormous progress has been made in understanding overall phylogenetic relationships in Caryophyllales. The process of re-circumscribing families in order to be monophyletic appears to be largely complete and has led to the recognition of eight new families (Anacampserotaceae, Kewaceae, Limeaceae, Lophiocarpaceae, Macarthuriaceae, Microteaceae, Montiaceae and Talinaceae), while the phylogenetic evaluation of generic concepts is still well underway. As a result of this, the number of genera has increased by more than ten percent in comparison to the last complete treatments in the Families and genera of vascular plants” series. A checklist with all currently accepted genus names in Caryophyllales, as well as nomenclatural references, type names and synonymy is presented. Notes indicate how extensively the respective genera have been studied in a phylogenetic context. The most diverse families at the generic level are Cactaceae and Aizoaceae, but 28 families comprise only one to six genera. This synopsis represents a first step towards the aim of creating a global synthesis of the species diversity in the angiosperm order Caryophyllales integrating the work of numerous specialists around the world.
198 citations
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TL;DR: This study is the first to address phylogenetic relationships within Spermacoceae from a tribal perspective and provides a phylogenetic hypothesis with broad sampling across the major lineages of Spermcoceae that can be used to guide future species-level and generic studies.
Abstract: In its current circumscription, the herbaceous tribe Spermacoceae s.l. (Rubiaceae, Rubioideae) unites the former tribes Spermacoceae s. str., Manettieae, and the Hedyotis–Oldenlandia group. Within Spermacoceae, and particularly within the Hedyotis–Oldenlandia group, the generic delimitations are problematic. Up until now, molecular studies have focused on specific taxonomic problems within the tribe. This study is the first to address phylogenetic relationships within Spermacoceae from a tribal perspective. Sequences of three plastid markers (atpB-rbcL, rps16, and trnL-trnF) were analyzed separately as well as combined using parsimony and Bayesian approaches. Our results support the expanded tribe Spermacoceae as monophyletic. The former tribe Spermacoceae s. str. forms a monophyletic clade nested within the Hedyotis–Oldenlandia group. Several genera formerly recognized within the Hedyotis–Oldenlandia group are supported as monophyletic (Amphiasma Bremek., Arcytophyllum Willd. ex Schult. & Schult. f., Dentella J. R. Forst. & G. Forst., Kadua Cham. & Schltdl., and Phylohydrax Puff), while others appear to be paraphyletic (e.g., Agathisanthemum Klotzsch), biphyletic (Kohautia Cham. & Schltdl.), or polyphyletic (Hedyotis L. and Oldenlandia L. sensu Bremekamp). Morphological investigations of the taxa are ongoing in order to find support for the many new clades and relationships detected. This study provides a phylogenetic hypothesis with broad sampling across the major lineages of Spermacoceae that can be used to guide future species-level and generic studies.
91 citations
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TL;DR: It is demonstrated that phylogenomic data can provide unparalleled insight into the evolutionary history of Caryophyllales and a method for overcoming computational challenges associated with homolog clustering in large data sets is discussed.
Abstract: Premise of the study The Caryophyllales contain ~12,500 species and are known for their cosmopolitan distribution, convergence of trait evolution, and extreme adaptations. Some relationships within the Caryophyllales, like those of many large plant clades, remain unclear, and phylogenetic studies often recover alternative hypotheses. We explore the utility of broad and dense transcriptome sampling across the order for resolving evolutionary relationships in Caryophyllales. Methods We generated 84 transcriptomes and combined these with 224 publicly available transcriptomes to perform a phylogenomic analysis of Caryophyllales. To overcome the computational challenge of ortholog detection in such a large data set, we developed an approach for clustering gene families that allowed us to analyze >300 transcriptomes and genomes. We then inferred the species relationships using multiple methods and performed gene-tree conflict analyses. Key results Our phylogenetic analyses resolved many clades with strong support, but also showed significant gene-tree discordance. This discordance is not only a common feature of phylogenomic studies, but also represents an opportunity to understand processes that have structured phylogenies. We also found taxon sampling influences species-tree inference, highlighting the importance of more focused studies with additional taxon sampling. Conclusions Transcriptomes are useful both for species-tree inference and for uncovering evolutionary complexity within lineages. Through analyses of gene-tree conflict and multiple methods of species-tree inference, we demonstrate that phylogenomic data can provide unparalleled insight into the evolutionary history of Caryophyllales. We also discuss a method for overcoming computational challenges associated with homolog clustering in large data sets.
70 citations
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TL;DR: Version 5 implements a number of new features and analytical methods allowing extensive DNA polymorphism analyses on large datasets, including visualizing sliding window results integrated with available genome annotations in the UCSC browser.
Abstract: Motivation: DnaSP is a software package for a comprehensive analysis of DNA polymorphism data. Version 5 implements a number of new features and analytical methods allowing extensive DNA polymorphism analyses on large datasets. Among other features, the newly implemented methods allow for: (i) analyses on multiple data files; (ii) haplotype phasing; (iii) analyses on insertion/deletion polymorphism data; (iv) visualizing sliding window results integrated with available genome annotations in the UCSC browser.
Availability: Freely available to academic users from: http://www.ub.edu/dnasp
Contact: [email protected]
13,511 citations
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TL;DR: A revised and updated classification for the families of the flowering plants is provided in this paper, which includes Austrobaileyales, Canellales, Gunnerales, Crossosomatales and Celastrales.
7,299 citations
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American Museum of Natural History1, Columbia University2, University of Hamburg3, Sao Paulo State University4, University of Richmond5, University of the Western Cape6, Natural History Museum7, University of Texas at Arlington8, Yahoo!9, Florida Fish and Wildlife Conservation Commission10, California Academy of Sciences11, University of Michigan12, National University of Colombia13, McGill University14
TL;DR: A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one, based on the largest phylogenetic analysis of living Amphibia so far accomplished, and many subsidiary taxa are demonstrated to be nonmonophyletic.
Abstract: The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living Amphibia so far accomplished. We combined the comparative anatomical character evidence of Haas (2003) with DNA sequences from the mitochondrial transcription unit H1 (12S and 16S ribosomal RNA and tRNAValine genes, ≈ 2,400 bp of mitochondrial sequences) and the nuclear genes histone H3, rhodopsin, tyrosinase, and seven in absentia, and the large ribosomal subunit 28S (≈ 2,300 bp of nuclear sequences; ca. 1.8 million base pairs; x = 3.7 kb/terminal). The dataset includes 532 terminals sampled from 522 species representative of the global diversity of amphibians as well as seven of the closest living relatives of amphibians for outgroup comparisons. The...
1,994 citations
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TL;DR: Despite the near-universal usage of ITS sequence data in plant phylogenetic studies, its complex and unpredictable evolutionary behavior reduce its utility for phylogenetic analysis, and it is suggested that more robust insights are likely to emerge from the use of single-copy or low-copy nuclear genes.
1,718 citations
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Duke University1, University of Texas at Austin2, Heidelberg Institute for Theoretical Studies3, American Museum of Natural History4, Beijing Genomics Institute5, Xi'an Jiaotong University6, New Mexico State University7, University of Sydney8, University of California9, Uppsala University10, University of Copenhagen11, Okinawa Institute of Science and Technology12, University of Georgia13, Griffith University14, Catalan Institution for Research and Advanced Studies15, Oak Ridge National Laboratory16, Joint Institute for Nuclear Research17, Aarhus University18, Washington University in St. Louis19, University of California, Santa Cruz20, Cardiff University21, Kunming Institute of Zoology22, China Agricultural University23, Tulane University24, Louisiana State University25, Copenhagen Zoo26, Federal University of Pará27, Oregon Health & Science University28, Technical University of Denmark29, Canterbury Museum30, Curtin University31, Novosibirsk State University32, Smithsonian Institution33, National University of Singapore34, National Museum of Natural History35, Nova Southeastern University36, Occidental College37, University of Edinburgh38, Harvard University39, University of California, San Francisco40, University of Florida41, University of Illinois at Urbana–Champaign42
TL;DR: A genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves recovered a highly resolved tree that confirms previously controversial sister or close relationships and identifies the first divergence in Neoaves, two groups the authors named Passerea and Columbea.
Abstract: To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.
1,624 citations