Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 9 of 9 for “"clinal variation"”.
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The Distributional Ecology of Three Uncommon Salamanders in Iowa
… elsewhere. Significant ontongenetic and slight clinal variation were observed among "A. texanum". A11 three species have declined in abundance in Iowa. "A. texanum" was found throughout southern Iowa. "N. v. louisianensis was confined to eastern Iowa and "A. Laterale" to the northeastern portion …
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Geographic Variation in the Morphology of <i>Crotalus horridus</i> (Serpentes: Viperidae)
… system, were used to analyze geographic variation in 36 morphological characters recorded from 2,420 specimens of <em>C. horridus</em> across its range.</p> <p>Sexual dimorphism was strong in ventral and subcaudal scales, and weak to moderate in band length and band spacing. Univariate …
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Phylogenetic revision of the genus Cherokia (Chamberlin, 1949) (Polydesmida: Xystodesmidae)
… with geographical distribution and elevation (clinal variation), but not with the phylogeny. Coloration was variable and did not accord with geography or phylogeny. The phylogeny recovered a monophyletic lineage, and the species delimitation test supports a single species. The molecular and …
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GENETIC STRUCTURE OF PINUS STROBUS L BASED ON FOLIAR ISOZYMES FROM 27 PROVENANCES
… frequencies at a few loci showed clinal variation with latitude. Central and marginal provenances were identified with cluster analysis, when all alleles were used. Another cluster analysis with frequencies of six alleles chosen for their high contributions to common variance in a …
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A comparison of the subspecific divergence of two sympatric African monkeys, Papio hamadryas & Chlorocebus aethiops: morphology, environment, diet & phylogeny
… and both exhibit extensive subspecific variation corresponding to geotypic forms. This thesis compares these two subspecific radiations, using skull morphology to characterise the two taxa, and attempts to determine if the two have been shaped by similar selective forces.The baboon …
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Vocalization Behavior of the Endangered Bahama Oriole (Icterus northropi): Ontogenetic, Sexual, Temporal, Duetting Pair, and Geographic Variation
… generalized dichotomy; to document sources of variation in vocalization rates and spectrographic structure; and to improve survey design for this critically endangered species. Accordingly, this study describes the primary vocalizations of the Bahama Oriole, and examines how vocalizations vary …
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Exploring the maintenance of plumage polymorphism in the Black Sparrowhawk
Animals often display striking variation with respect to their phenotype. Intraspecific and interspecific variation in body colour represents one of the most well studied forms of phenotypic variation. For decades evolutionary biologists have been fascinated by the mechanisms that maintain colour …
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Thermal adaptation in butterflies: patterns, significance and mechanisms
… As in nature organisms are often faced with variation in mean temperatures as well as in temperature extremes, they have to adapt plastically and/or genetically to their respective environmental conditions or will otherwise risk extinction. Using the Copper butterfly Lycaena tityrus as model …
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Systematics of Eastern North American Bracken Fern
… populations. Strong patterns of geographic variation for isozyme allele frequencies were also observed. The isozyme results did not separate the two taxa. Numerical analysis of the morphology distinguished the two taxa when the qualitative characters were used alone or in conjunction with …