Testing Models of Early Paleoindian Colonization and Adaptation Using Cladistics
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Understanding Cladistics
Understanding Cladistics Activity for Grades 5–8 Introduction Objective At the American Museum of Natural History, In this activity, students will explore cladistics and scientists use a method called cladistics to group create a cladogram of their own. animals. They look for unique features, such as a hole in the hip socket, that the animals share. Materials Animals with like features are grouped together. A • Understanding Cladistics chart, called a cladogram, shows these relationships. • A penny, nickel, dime, and quarter for each pair Using cladistics, scientists can reconstruct genealogi- of students cal relationships and can show how animals are • 6-8 dinosaurs pictures duplicated for each group, linked to one another through a long and complex downloadable from history of evolutionary changes. amnh.org/resources/rfl/pdf/dino_16_illustrations.pdf Procedure 1. Write lion, elephant, zebra, kangaroo, koala, buffalo, raccoon, and alligator. Ask students how the animals are related and what might be a good way of grouping them into sets and subsets. Discuss students responses. Tyrannosaurus rex Apatosaurus excelsus 2. Explain to students that scientists use a method extinct extinct called cladistics to determine evolutionary relation- ships among animals. They look for features that animals share, such as four limbs, hooves, or a hole in the hip socket. Animals with like features are grouped together. Scientists make a chart called a cladogram to show these relationships. 3. Tell students that they will examine the features of various coins to determine how they are related. Remind students that cladistics is used to determine relationships among organisms, and Theropoda Sauropoda Foot with three main At least 11 or more not necessarily objects. -
Species Tree Likelihood Computation Given SNP Data Using Ancestral Configurations
Species Tree Likelihood Computation Given SNP Data Using Ancestral Configurations DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Hang Fan, M.S. Graduate Program in Statistics The Ohio State University 2013 Dissertation Committee: Professor Laura Kubatko, Advisor Professor Bryan Carstens Professor Radu Herbei 1 Copyright by Hang Fan 2013 2 Abstract Inferring species trees given genetic data has been a challenge in the field of phylogenetics because of the high intensity during computation. In the coalescent framework, this dissertation proposes an innovative method of estimating the likelihood of a species tree directly from Single Nucleotide Polymorphism (SNP) data with a certain nucleotide substitution model. This method uses the idea of Ancestral Configurations (Wu, 2011) to avoid the computation burden brought by the enumeration of coalescent histories. Importance sampling is used to in Monte Carlo integration to approximate the expectations in the computation, where the accuracy of the approximation is tested in different tree models. The SNP data is processed beforehand which vastly boosts the efficiency of the method. Gene tree sampling given the species tree under the coalescent model is employed to make the computation feasible for large trees. Further, the branch lengths on the species tree are optimized according to the computed species tree likelihood, which provides the likelihood of the species tree topology given the SNP data. For inference, this likelihood computation method is implemented in the stepwise addition algorithm to infer the maximum likelihood species tree in the tree space given the SNP data, and simulations are conduced to test the performance. -
EVOLUTIONARY INFERENCE: Some Basics of Phylogenetic Analyses
EVOLUTIONARY INFERENCE: Some basics of phylogenetic analyses. Ana Rojas Mendoza CNIO-Madrid-Spain. Alfonso Valencia’s lab. Aims of this talk: • 1.To introduce relevant concepts of evolution to practice phylogenetic inference from molecular data. • 2.To introduce some of the most useful methods and computer programmes to practice phylogenetic inference. • • 3.To show some examples I’ve worked in. SOME BASICS 11--ConceptsConcepts ofof MolecularMolecular EvolutionEvolution • Homology vs Analogy. • Homology vs similarity. • Ortologous vs Paralogous genes. • Species tree vs genes tree. • Molecular clock. • Allele mutation vs allele substitution. • Rates of allele substitution. • Neutral theory of evolution. SOME BASICS Owen’s definition of homology Richard Owen, 1843 • Homologue: the same organ under every variety of form and function (true or essential correspondence). •Analogy: superficial or misleading similarity. SOME BASICS 1.Concepts1.Concepts ofof MolecularMolecular EvolutionEvolution • Homology vs Analogy. • Homology vs similarity. • Ortologous vs Paralogous genes. • Species tree vs genes tree. • Molecular clock. • Allele mutation vs allele substitution. • Rates of allele substitution. • Neutral theory of evolution. SOME BASICS Similarity ≠ Homology • Similarity: mathematical concept . Homology: biological concept Common Ancestry!!! SOME BASICS 1.Concepts1.Concepts ofof MolecularMolecular EvolutionEvolution • Homology vs Analogy. • Homology vs similarity. • Ortologous vs Paralogous genes. • Species tree vs genes tree. • Molecular clock. -
The Probability of Monophyly of a Sample of Gene Lineages on a Species Tree
PAPER The probability of monophyly of a sample of gene COLLOQUIUM lineages on a species tree Rohan S. Mehtaa,1, David Bryantb, and Noah A. Rosenberga aDepartment of Biology, Stanford University, Stanford, CA 94305; and bDepartment of Mathematics and Statistics, University of Otago, Dunedin 9054, New Zealand Edited by John C. Avise, University of California, Irvine, CA, and approved April 18, 2016 (received for review February 5, 2016) Monophyletic groups—groups that consist of all of the descendants loci that are reciprocally monophyletic is informative about the of a most recent common ancestor—arise naturally as a conse- time since species divergence and can assist in representing the quence of descent processes that result in meaningful distinctions level of differentiation between groups (4, 18). between organisms. Aspects of monophyly are therefore central to Many empirical investigations of genealogical phenomena have fields that examine and use genealogical descent. In particular, stud- made use of conceptual and statistical properties of monophyly ies in conservation genetics, phylogeography, population genetics, (19). Comparisons of observed monophyly levels to model pre- species delimitation, and systematics can all make use of mathemat- dictions have been used to provide information about species di- ical predictions under evolutionary models about features of mono- vergence times (20, 21). Model-based monophyly computations phyly. One important calculation, the probability that a set of gene have been used alongside DNA sequence differences between and lineages is monophyletic under a two-species neutral coalescent within proposed clades to argue for the existence of the clades model, has been used in many studies. Here, we extend this calcu- (22), and tests involving reciprocal monophyly have been used to lation for a species tree model that contains arbitrarily many species. -
Character Analysis in Cladistics: Abstraction, Reification, and the Search for Objectivity
Acta Biotheor (2009) 57:129–162 DOI 10.1007/s10441-008-9064-7 REGULAR ARTICLE Character Analysis in Cladistics: Abstraction, Reification, and the Search for Objectivity Rasmus Grønfeldt Winther Received: 10 October 2008 / Accepted: 17 October 2008 / Published online: 7 January 2009 Ó Springer Science+Business Media B.V. 2009 Abstract The dangers of character reification for cladistic inference are explored. The identification and analysis of characters always involves theory-laden abstraction—there is no theory-free ‘‘view from nowhere.’’ Given theory-ladenness, and given a real world with actual objects and processes, how can we separate robustly real biological characters from uncritically reified characters? One way to avoid reification is through the employment of objectivity criteria that give us good methods for identifying robust primary homology statements. I identify six such criteria and explore each with examples. Ultimately, it is important to minimize character reification, because poor character analysis leads to dismal cladograms, even when proper phylogenetic analysis is employed. Given the deep and systemic problems associated with character reification, it is ironic that philosophers have focused almost entirely on phylogenetic analysis and neglected character analysis. Keywords Characters Á Cladistics Á Phylogenetics Á Morphology Á Abstraction Á Reification Á Biological theory Á Epistemology Á Causation How are we to recognize the ‘‘true’’ characters of organisms rather than imposing upon them arbitrary divisions that obscure the very processes that we seek to understand? …No issue is of greater importance in the study of biology. –Lewontin 2001, p. xvii Are characters natural units or artifacts of observation and description? In both systematics and ecology, there is often a considerable gulf between observables and the units that play causal roles in our models. -
Outer and Inner Indo-Aryan, and Northern India As an Ancient Linguistic Area
Acta Orientalia 2016: 77, 71–132. Copyright © 2016 Printed in India – all rights reserved ACTA ORIENTALIA ISSN 0001-6483 Outer and Inner Indo-Aryan, and northern India as an ancient linguistic area Claus Peter Zoller University of Oslo Abstract The article presents a new approach to the old controversy concerning the veracity of a distinction between Outer and Inner Languages in Indo-Aryan. A number of arguments and data are presented which substantiate the reality of this distinction. This new approach combines this issue with a new interpretation of the history of Indo- Iranian and with the linguistic prehistory of northern India. Data are presented to show that prehistorical northern India was dominated by Munda/Austro-Asiatic languages. Keywords: Indo-Aryan, Indo-Iranian, Nuristani, Munda/Austro- Asiatic history and prehistory. Introduction This article gives a summary of the most important arguments contained in my forthcoming book on Outer and Inner languages before and after the arrival of Indo-Aryan in South Asia. The 72 Claus Peter Zoller traditional version of the hypothesis of Outer and Inner Indo-Aryan purports the idea that the Indo-Aryan Language immigration1 was not a singular event. Yet, even though it is known that the actual historical movements and processes in connection with this immigration were remarkably complex, the concerns of the hypothesis are not to reconstruct the details of these events but merely to show that the original non-singular immigrations have left revealing linguistic traces in the modern Indo-Aryan languages. Actually, this task is challenging enough, as the long-lasting controversy shows.2 Previous and present proponents of the hypothesis have tried to fix the difference between Outer and Inner Languages in terms of language geography (one graphical attempt as an example is shown below p. -
Crown Clades in Vertebrate Nomenclature
2008 POINTS OF VIEW 173 Wiens, J. J. 2001. Character analysis in morphological phylogenetics: Wilkins, A. S. 2002. The evolution of developmental pathways. Sinauer Problems and solutions. Syst. Biol. 50:689–699. Associates, Sunderland, Massachusetts. Wiens, J. J., and R. E. Etheridge. 2003. Phylogenetic relationships of Wright, S. 1934a. An analysis of variability in the number of digits in hoplocercid lizards: Coding and combining meristic, morphometric, an inbred strain of guinea pigs. Genetics 19:506–536. and polymorphic data using step matrices. Herpetologica 59:375– Wright, S. 1934b. The results of crosses between inbred strains 398. of guinea pigs differing in number of digits. Genetics 19:537– Wiens, J. J., and M. R. Servedio. 1997. Accuracy of phylogenetic analysis 551. including and excluding polymorphic characters. Syst. Biol. 46:332– 345. Wiens, J. J., and M. R. Servedio. 1998. Phylogenetic analysis and in- First submitted 28 June 2007; reviews returned 10 September 2007; traspecific variation: Performance of parsimony, likelihood, and dis- final acceptance 18 October 2007 tance methods. Syst. Biol. 47:228–253. Associate Editor: Norman MacLeod Syst. Biol. 57(1):173–181, 2008 Copyright c Society of Systematic Biologists ISSN: 1063-5157 print / 1076-836X online DOI: 10.1080/10635150801910469 Crown Clades in Vertebrate Nomenclature: Correcting the Definition of Crocodylia JEREMY E. MARTIN1 AND MICHAEL J. BENTON2 1UniversiteL´ yon 1, UMR 5125 PEPS CNRS, 2, rue Dubois 69622 Villeurbanne, France; E-mail: [email protected] 2Department of Earth Sciences, University of Bristol, Bristol, BS9 1RJ, UK; E-mail: [email protected] Downloaded By: [Martin, Jeremy E.] At: 19:32 25 February 2008 Acrown group is defined as the most recent common Dyke, 2002; Forey, 2002; Monsch, 2005; Rieppel, 2006) ancestor of at least two extant groups and all its descen- but rather expresses dissatisfaction with the increasingly dants (Gauthier, 1986). -
The Shape of Phylogenetic Trees (Review Paper)
REVIEW PAPER: THE SHAPE OF PHYLOGENETIC TREESPACE KATHERINE ST. JOHN Abstract: Trees are a canonical structure for representing evolutionary histories. Many popular criteria used to infer optimal trees are computationally hard, and the number of possible tree shapes grows super-exponentially in the number of taxa. The underlying structure of the spaces of trees yields rich insights that can improve the search for optimal trees, both in accuracy and running time, and the analysis and visualization of results. We review the past work on analyzing and comparing trees by their shape as well as recent work that incorporates trees with weighted branch lengths. Keywords: tree metrics, treespace, maximum parsimony, maximum likelihood. Tree structures have long been used to represent the evolutionary histories of sets of species. For example, the tips of the trees represent extant species and the internal nodes represent speciation events. Despite its simplicity, the tree model captures much of the complexity of the underlying phenomena. However, the sheer number of possibilities forces many simply presented operations on trees to be computationally hard. For example, the maximum parsimony criteria (Farris, 1970; Fitch, 1971) that seeks the tree with the minimal number of changes across the edges is compu- tationally hard to compute exactly (Foulds and Graham, 1982). The addition of weights on the branches, to denote quantities such as amount of evolutionary change, the time, or the confidence on the existence of the branch, adds complexity to the model (Felsenstein, 1973, 1978). A pop- ular corresponding optimality criteria for weighted trees, the maximum likelihood criteria, is also computationally hard (Roch, 2006). -
Cladistics: Definition of Terms Amniotic Egg: Includes Several Extensive Membranes, the Amnion, Chorion, and Allantois
Cladistics: Definition of Terms Amniotic egg: includes several extensive membranes, the amnion, chorion, and allantois. The egg is contained in an amniotic sac, as, for example, in the human fetus. Clade: a group of organisms including their common ancestor and all descendants that have evolved from that common ancestor. Cladistics: a system of classification based on shared derived characters that arranges organisms only by their branching in an evolutionary tree. Cladogram: a tree-shaped diagram used to illustrate evolutionary relationships among species by analyz- ing certain kinds of characters, or physical features, � � � � in the organisms. A cladogram starts with the root, which then splits several times. As you follow along �������� Outgroup ������ on a cladogram, it will split at nodes into two or more internodes. The node represents a speciation ������� event (the formation of a new species). The line ��������� between two speciation events, the internode, rep- ���� resents at least one hypothetical ancestor. Described ���� species (either from the present or from the fossil record), known as terminal taxa, appear at the tips or ends of the branches. Characters that are used to define a group or clade (shared derived characters) can be drawn on the internode leading to the node defining the clade. Characters: physical features shared by a group of organisms. These characters correspond to the specific traits of an organism. For example, if the character is vertebrae, then one of the traits of a particular species is the presence or absence of vertebrae. Characters that are new, and not present in an outgroup or ancestor, are called derived. Characters that are present in an ancestor of a studied group are called ancestral. -
Autochthonous Aryans? the Evidence from Old Indian and Iranian Texts
Michael Witzel Harvard University Autochthonous Aryans? The Evidence from Old Indian and Iranian Texts. INTRODUCTION §1. Terminology § 2. Texts § 3. Dates §4. Indo-Aryans in the RV §5. Irano-Aryans in the Avesta §6. The Indo-Iranians §7. An ''Aryan'' Race? §8. Immigration §9. Remembrance of immigration §10. Linguistic and cultural acculturation THE AUTOCHTHONOUS ARYAN THEORY § 11. The ''Aryan Invasion'' and the "Out of India" theories LANGUAGE §12. Vedic, Iranian and Indo-European §13. Absence of Indian influences in Indo-Iranian §14. Date of Indo-Aryan innovations §15. Absence of retroflexes in Iranian §16. Absence of 'Indian' words in Iranian §17. Indo-European words in Indo-Iranian; Indo-European archaisms vs. Indian innovations §18. Absence of Indian influence in Mitanni Indo-Aryan Summary: Linguistics CHRONOLOGY §19. Lack of agreement of the autochthonous theory with the historical evidence: dating of kings and teachers ARCHAEOLOGY __________________________________________ Electronic Journal of Vedic Studies 7-3 (EJVS) 2001(1-115) Autochthonous Aryans? 2 §20. Archaeology and texts §21. RV and the Indus civilization: horses and chariots §22. Absence of towns in the RV §23. Absence of wheat and rice in the RV §24. RV class society and the Indus civilization §25. The Sarasvatī and dating of the RV and the Bråhmaas §26. Harappan fire rituals? §27. Cultural continuity: pottery and the Indus script VEDIC TEXTS AND SCIENCE §28. The ''astronomical code of the RV'' §29. Astronomy: the equinoxes in ŚB §30. Astronomy: Jyotia Vedåga and the -
Application of Cladistics to the Analysis of Genotype-Phenotype Relationships
Eur. J. Epidemiol. 0392-2990 EUROPEAN Vol. 8, Suppl. to No. 2 Suppl. 1, 1992, p, 3-9 JOURNAL OF EPIDEMIOLOGY APPLICATION OF CLADISTICS TO THE ANALYSIS OF GENOTYPE-PHENOTYPE RELATIONSHIPS C.F. SING 1, M.B. HAVILAND, K.E. ZERBA and A.R. TEMPLETON The University of Michigan Medical School - Medical Science 1I M4708 ANN ARBOR - MI 48109-0618 - USA. Key words: Atherosclerosis - Cladistics - Genetics We seek to understand the relative contribution of allelic variations of a particular gene to the determination of an individual's risk ofatherosclerosis or hypertension. Work in progress is focusing on the identification and characterization of mutations in candidate genes that are known to be involved in determining the phenotypic expression of intermediate biochemical and physiological traits that are in the pathway of causation between genetic variation and variation in risk of disease. The statistical strategy described in this paper is designed to aid geneticists and molecular biologists in their search to find the DNA sequences responsible for the genetic component of variation in these traits. With this information we will have a more complete understanding of the nature of the organization of the genetic variation responsible for quantitative variation in risk of disease. It will then be possible to fully evaluate the utility of measured genetic information in predicting the risk of common diseases having a complex multifactorial etiology, such as atherosclerosis and hypertension. INTRODUCTION biological risk factor traits that influence risk of disease are continuously distributed among relatives. Numerous quantitative biological traits contribute There is no known combination of phenotypes in an to determining an individual's risk of developing a individual for which risk is totally absent or disease an common complex disease such as atherosclerosis or absolute certainty. -
A Synapomorphy-Based Multiple Sequence Alignment Method. Cladistics, 19:261
Cladistics Cladistics 19 (2003) 261–268 www.elsevier.com/locate/yclad Implied alignment: a synapomorphy-based multiple-sequence alignment method and its use in cladogram search Ward C. Wheeler* Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79thSt., New York, NY 10024-5192, USA Accepted 7 April 2003 Abstract A method to align sequence data based on parsimonious synapomorphy schemes generated by direct optimization (DO; earlier termed optimization alignment) is proposed. DO directly diagnoses sequence data on cladograms without an intervening multiple- alignment step, thereby creating topology-specific, dynamic homology statements. Hence, no multiple-alignment is required to generate cladograms. Unlike general and globally optimal multiple-alignment procedures, the method described here, implied alignment (IA), takes these dynamic homologies and traces them back through a single cladogram, linking the unaligned sequence positions in the terminal taxa via DO transformation series. These ‘‘lines of correspondence’’ link ancestor–descendent states and, when displayed as linearly arrayed columns without hypothetical ancestors, are largely indistinguishable from standard multiple alignment. Since this method is based on synapomorphy, the treatment of certain classes of insertion–deletion (indel) events may be different from that of other alignment procedures. As with all alignment methods, results are dependent on parameter assumptions such as indel cost and transversion:transition ratios. Such an IA could be used as a basis for phylogenetic search, but this would be questionable since the homologies derived from the implied alignment depend on its natal cladogram and any variance, between DO and IA + Search, due to heuristic approach. The utility of this procedure in heuristic cladogram searches using DO and the im- provement of heuristic cladogram cost calculations are discussed.