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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Phylogenetic analysis, systematics, and evolution of early Ordovician graptolites /

Carlucci, Jesse. January 2008 (has links)
Thesis (M.S.)--State University of New York at Buffalo, 2008. / Includes bibliographical references (p. 104-111). Also available online.
2

The cephalic lateralis system of cardinalfishes (Perciformes: Apogonidae) and its application to the taxonomy and systematics of the family

Bergman, Laura M. Rodman. January 2004 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 349-373).
3

Understanding the importance of taxonomic sampling for large-scale phylogenetic analyses by simulating evolutionary processes under complex models

Heath, Tracy Ann. January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.
4

Phylogenetic analysis of the bryozoan Suborder Rhabdomesina

Paquette, Lance. January 2008 (has links)
Thesis (M.S.)--Michigan State University. Geological Sciences, 2008. / Title from PDF t.p. (viewed on July 28, 2009) Includes bibliographical references (p. 64-71). Also issued in print.
5

Phylogenetic analyses and taxonomic studies of Senecioninae : southern African Senecio section Senecio /

Milton, Joseph J. January 2009 (has links)
Thesis (Ph.D.) - University of St Andrews, May 2009.
6

On a cladistic taxonomy of organismic traits /

Pearson, Christopher H., January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 154-156).
7

Phylogenetic studies of cyanobacterial lichens /

Högnabba, Filip. January 2007 (has links)
Thesis (doctoral)--Helsingin yliopisto, 2007. / Includes bibliographical references. Also available in PDF format via the internet.
8

Anatomical variation in Cactaceae sensu lato

Ogburn, R. Matthew. January 2007 (has links)
Title from title page of PDF (University of Missouri--St. Louis, viewed March 2, 2010). Includes bibliographical references (p. 56-60).
9

Understanding the importance of taxonomic sampling for large-scale phylogenetic analyses by simulating evolutionary processes under complex models

Heath, Tracy Ann 12 October 2012 (has links)
Appropriate and extensive taxon sampling is one of the most important determinants of accurate phylogenetic estimation. In addition, accuracy of inferences about evolutionary processes obtained from phylogenetic analyses is improved significantly by thorough taxon sampling efforts. Much of the previous work examining the impact of taxon sampling on phylogenetic accuracy has focused on the effects of random taxon sampling or directed taxon addition/removal. Therefore, the effect of realistic, nonrandom taxon sampling strategies on the accuracy of large-scale phylogenetic reconstruction is not well understood. Typically, broad systematic studies of diverse clades select species according to current classification to span the diversity within the group of interest. I simulated phylogenies under a realistic model of cladogenesis and used these trees to generate sequence data. Using these simulations, I explored the effect of taxonomy-based taxon sampling on the accuracy of maximum likelihood reconstruction. The results demonstrate that taxonomy-based sampling has a stronger, negative, effect on phylogenetic accuracy than random taxon sampling. Therefore, it is recommended that systematists conducting phylogenetic analyses of diverse clades concentrate on improving sampling density within their group of interest by selecting multiple representatives from each taxonomic level. Phylogenetic tree imbalance is often used to make inferences about macroevolutionary processes that generate patterns of tree shape. However these patterns may be obscured by non-biological factors that can bias tree shape. Using published trees inferred from biological data and trees simulated under a realistic branching model; I investigated the affect of random taxon omission on phylogenetic tree imbalance. My results indicate that incomplete taxon sampling in the presence of variable rates of speciation and extinction may be sufficient to explain much of the imbalance observed in empirical phylogenies. Previous research has indicated that some methods of phylogenetic inference can produce biased tree topologies and shapes. Using simulated model tree topologies and sequence data, I investigated the non-biological factors that lead to biases in phylogenetic tree imbalance. Based on my results, I concluded that phylogenetic noise is the primary cause of tree shape bias. Methods that account for unobserved substitutions, such as maximum likelihood, can overcome the systematic bias toward imbalanced topologies. / text
10

The procolophonid Barasaurus and the phylogeny of early amniotes

Meckert, Dirk January 1995 (has links)
The procolophonid amniote Barasaurus besairiei Piveteau 1955 is fully described and restored for the first time with emphasis placed on the postcranial skeleton, which is only poorly known in most of the other taxa of early amniotes. / The study focuses on testing a hypothesis of relationships, namely whether procolophonids are the sister-group of Testudines as proposed by Reisz & Laurin (1991). The description provides a sound basis for a new phylogenetic study of early amniotes. Using 13 taxa and 68 characters, the analysis indicates that synapsids are the sister-group of all other known amniotes, named Sauropsida. The Sauropsida are divided into Palaeosauropsida and Eusauropsida. Palaeosauropsida comprise Millerettidae as the sister-group of Procolophoniformes. The Procolophoniformes contain Procolophonia and Testudinomorpha as sister-groups. Testudines are the sister-group of Pareiasauria within the Testudinomorpha. Within Procolophonia, the family Owenettidae, including Barasaurus and Owenetta, is the sister-group of the family Procolophonidae. Eusauropsida include captorhinids, Palaeothyris and diapsids. / All of the three major amniote clades have extant taxa: Synapsida--mammals; Palaeosauropsida--turtles; Eusauropsida--diapsids including birds. The terms "Reptilia" and "Parareptilia" are omitted from systematics: Parareptilia for a misleading name and Reptilia in general because of its historical burden. / The new tree is strong in supporting Procolophonia and Testudinomorpha (sister-group of Pareiasauria and Testudines). It is not very firm in establishing eusauropsids and diadectomorphs because they were outside the main focus of the analysis. Mesosauria is the only group of Palaeozoic amniotes not included in this study.

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