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.
Results
Showing 1 to 14 of 14 for “"species pair"”.
-
Genetic differentiation of a sympatric lake-resident/anadromous species pair of threespine stickleback in Mud Lake, Alaska
<p>The formation of new species is responsible for all the biological diversity we see on Earth. This process of speciation is not yet fully understood and is most often studied by comparing individuals of closely related species. The threespine stickleback, Gasterosteus aculeatus, a fish species …
-
Distinguishing the Treefrogs "Hyla versicolor" and "Hyla chrysoscelis" in Iowa, and Their Distributions
Historically, the tetraploid and diploid species pair of treefrogs, "Hyla versicolor" and "Hyla chrysoscelis" have been mapped collectively in Iowa because no distinguishing macroscopic morphological characteristics useful in recognizing the two species had been found. The present study reports …
-
Waterfowl Breeding Pair and Brood Usage of Oxbows and Riverine Habitats on the James River
<p>Waterfowl breeding pair and brood surveys were conducted along 250 km of the James River and adjacent oxbows in Brown and Spink Counties, South Dakota during 1987-88. Invertebrates were sampled at brood survey sites in 1988. All of the oxbows and river segments in 1987 contained sufficient water …
-
Comparative antifreeze trait analyses of Antarctic and temperate sister species pairs shed light on tempo of adaptive trait loss under relaxed selection
… in select secondarily temperate notothenioid species when selective pressure no longer exists. The magnitude of the change in AFGP trait expression could inform on the evolutionary history of these species since the AFGP gene evolved only once in notothenioids. We determined the evolutionary …
-
Comparisons of Captive Gibbons’ (Hylobatidae) Intrapair Behaviors Indicative of the Pair Bond
I aimed to better understand captive gibbons’ pair bonds by studying behaviors that may indicate the relationship’s quality. I completed this research at The Gibbon Conservation Center (GCC) in Santa Clarita, California and observed four species: eastern hoolock (<em>Hoolock leuconedys</em>), Javan …
-
Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands
… to better understand the processes governing species distributions and associated evolutionary divergence in rodents inhabiting mesic conditions in the Neotropics. Focusing on a widespread rodent from northern South America (Heteromys anomalus), in the first chapter I proposed and tested a …
-
MATING COSTS, MALE CHOICE DISPLACEMENT, AND THE EFFECTS ON HYBRIDIZATION AND SPECIATION IN THE HAWAIIAN CRICKET LAUPALA (SUBFAMILY:TRIGONIDIINAE)
Contact zones between two closely-related species provide unique laboratories for studying the processes of speciation. This is because, within these zones, species barriers will be reinforced and speciation will reach completion, or the barriers will break down, causing the two species to become …
-
Soil factors and competition as determinants of fynbos plant species distributions in the South-western Cape, South Africa
The Cape Floristic Region is one of the most species-rich regions of the world. Fynbos, the Mediterranean climate shrubland which comprises the largest part of this region, is characterized by high beta diversity and high edaphic endemism. However, very few quantitative studies of the factors …
-
Seasonal changes in the foraging methods and habitats of six sympatric woodpecker species in southwestern Virginia
… and winter. The food resource used by the six species was partitioned by species' use of different macro-habitats (forest structure), micro-habitats (positions within trees), and foraging methods. Differences in foraging behaviors of male and female downy and hairy woodpeckers were also …
-
Exploiters and exploited: antagonism, mutualism and mimicry in an ecological community
Interactions between species shape the natural world, and range along a continuum from mutualistic (benefitting all parties) to antagonistic (harming at least one party). Typically, interacting species are studied in a pairwise manner, and such studies have yielded a wealth of insights. However, …
-
Investigation of multiple interspecific reproductive barriers in Solanum section Lycopersicon
… close relatives and provide insight on how species maintain their integrity in nature. Wild tomato species (Solanum Section. Lycopersicon) are useful for studying IRBs. The monophyletic tomato clade includes 13 closely related species that possess a variety of mating systems and complex …
-
Aspects of population dynamics
… of seasonal variations of the environment on species coexistence. The results of our simulations are also compared to a mean-field analysis. We find that the parameter region of predator and prey coexistence is enlarged relative to the stationary situation when the carrying capacity varies …
-
Population genetics of the cichlid, Cynotilapia afra (Günther 1894), in its native and introduced ranges in Lake Malawi
Species introductions can provide unplanned and occasionally replicated experiments that can be studied to understand fundamental ecological and evolutionary processes associated with range expansions in the natural world. The cichlid species flock of Lake Malawi consists of an estimated 451-800 …