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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.
11

Influence of climatic fluctuations in Neogene/on evolution of ecologically diverse plant genus: an example of Hippophae L. (Elaeagnaceae)

Jia, Dongrui January 2013 (has links)
The Neogene geologic processes and climatic changes had tremendous impact on evolution of biota in different regions of Northern Hemisphere (NH). The Qinghai- Tibetan Plateau (QTP) was a central part of these processes. Migrations from the QTP to other temperate regions represent one of the main biogeographic patterns for Northern Hemisphere. However, this 'out-of-QTP' hypothesis has never been tested through a phylogeographic analysis of a widely distributed species and the ages and routs of these migrations are largely not resolved. On the other hand, climate change played an important role in shaping the amount and structure of intraspecific genetic diversity, which provide the main basic substrate for any evolutionary change. Therefore, a detailed understanding of the effects of historic climate alterations on intraspecific genetic diversity can provide valuable insights into the evolutionary consequences of past climate changes and predicting the likely direction of global warming effects on sustainability of extant populations and species. In this thesis, I first studied the phylogeography of Hippophae rhamnoides to test the 'out-of-QTP' hypothesis (Chapter II). Then, I performed phylogenetic, dating and biogeographic analyses of the genus Hippophae (Chapter III). Finally, I studied the...
12

Phylogeography and geographical variation of behavioral and morphological characteristics in Paruroctonus boreus

Miller, Abraham. January 2008 (has links)
Thesis (Ph.D.) -- University of Texas at Arlington, 2008.
13

Phylogeography of the Cellana limpets of New Zealand: Investigating Barriers to Marine Dispersal and Historical Biogeography

Goldstien, Sharyn Jane January 2005 (has links)
New Zealand is a continental island surrounded by deep-ocean, with a complex system of currents and oceanographic anomalies that may serve to isolate populations of coastal marine organisms. In particular Cook Strait is a 26 km wide body of water separating the North and South Islands which is characterised by complex interactions of tides and converging water masses. Cook Strait is a geologically recent formation that may also impart an historical influence on the biogeographic distribution of coastal marine taxa. In order to investigate the phylogeographic structure of coastal marine taxa around New Zealand's coastline and to investigate the processes that may contribute toward this genetic structure, I analysed mitochondrial DNA genes from limpet species of the Cellana genus. Phylogenetic analyses of the ribosomal 12S and 16S DNA genes showed that C. ornata may approximate the founding lineage to New Zealand, but these genes were unable to resolve between contrasting biogeographic hypotheses about the origin of Cellana in New Zealand. Intraspecific analyses of the mitochondrial cytochrome b gene from populations throughout the biogeographic range of Cellana ornata, C. radians and C. flava showed concordant genetic discontinuity at Cook Strait. Further analyses suggest that allopatric fragmentation and restricted gene flow have caused significant genetic differentiation between populations of the North and South Island. Demographic expansion was also identified for C. radians. The influence of contemporary nearshore currents and sea surface temperature was assessed using the mitochondrial cytochrome b gene for C. radians and C. ornata. Low levels of genetic differentiation between populations corresponding to 'current-zones' suggests that contemporary oceanic processes may be contributing to the genetic pattern observed for these species. However, the shallow divergence between haplotypes and populations restricted thorough investigation of contemporary gene flow. Genealogical concordance across co-distributed marine taxa of New Zealand also lends support to the historic association of genetic and species discontinuities with recent geological changes, such as sea level fluctuations.
14

Genetic structure and phylogeography of the fox squirrel, Sciurus niger, as inferred from a mitochondrial gene

Bryant, Katherine L., January 2007 (has links)
Thesis (M.S.)--George Mason University, 2007. / Title from PDF t.p. (viewed Jan. 17, 2008). Thesis director: Cody W. Edwards Submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Science and Policy. Vita: p. 46. Includes bibliographical references (p. 37-45). Also available in print.
15

A mtDNA study of aspects of the recent evolutionary history and phylogeographic structure of selected teleosts in coastal environments of south-western Australia /

Hoddell, Richard James. January 2003 (has links)
Thesis (Ph.D.)--Murdoch University, 2003. / Thesis submitted to the Division of Science and Engineering. Bibliography: leaves 273-299.
16

Phylogeography and population genetics of Carex macrocephala, and the molecular evolution of Carex subgenus Vignea

King, Matthew George, January 2007 (has links) (PDF)
Thesis (Ph. D.)--Washington State University, December 2007. / Includes bibliographical references.
17

Genetic diversity in the anabantids Sandelia capensis and S. Bainsii a phylogeographic and phylogenetic investigation /

Roos, Heidi. January 2004 (has links)
Thesis M.Sc.)(Genetics)--University of Pretoria, 2005. / Title from opening screen (viewed 11 April 2005). Includes summary. Includes bibliographical references.
18

Phylogeography of the sigmodontine rodent, phyllotis xanthopygus, and a test of the sensitivity of nested clade analysis to elevation-based alternative distances

Albright, James C. Steppan, Scott J. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Scott Steppan, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Title and description from dissertation home page (viewed Jan. 18, 2005). Includes bibliographical references.
19

Comparative phylogeography of two skink species in southern Africa

Portik, Daniel M. January 2009 (has links)
Thesis (M.S.)--Villanova University, 2009. / Biology Dept. "Funding for this study provided by the National Science Foundation (grant number: DEB 0515909)"-- l. ii. Includes bibliographical references.
20

Biogeography and speciation of southwestern Australian frogs /

Edwards, Danielle L. January 2007 (has links)
Thesis (Ph.D.)--University of Western Australia, 2007.

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