Search results for "competition."
showing 7 items of 1367 documents
Frequency and Density-Dependent Selection on Life-History Strategies - A Field Experiment
2008
Negative frequency-dependence, which favors rare genotypes, promotes the maintenance of genetic variability and is of interest as a potential explanation for genetic differentiation. Density-dependent selection may also promote cyclic changes in frequencies of genotypes. Here we show evidence for both density-dependent and negative frequency-dependent selection on opposite life-history tactics (low or high reproductive effort, RE) in the bank vole (Myodes glareolus). Densitydependent selection was evident among the females with low RE, which were especially favored in low densities. Instead, both negative frequency-dependent and density-dependent selection were shown in females with high RE…
The Effect of Predator Population Dynamics on Batesian Mimicry Complexes.
2022
Understanding Batesian mimicry is a classic problem in evolutionary biology. In Batesian mimicry, a defended species (the model) is mimicked by an undefended species (the mimic). Prior theories have emphasized the role of predator behavior and learning as well as evolution in model-mimic complexes but have not examined the role of population dynamics in potentially governing the relative abundances and even persistence of model-mimic systems. Here, we examined the effect of the population dynamics of predators and alternative prey on the prevalence of warning-signaling prey composed of models and mimics. Using optimal foraging theory and signal detection theory, we found that the inclusion …
The impact of summertime food consumption by vendace on the abundance of zooplankton the following spring
2008
Wybory niekonkurencyjne w Polsce na poziomie lokalnym – wstępne oceny
2020
Artykuł podejmuje problem obsadzania mandatów bez głosowania w wyborach do rad gmin w gminach liczących do 20 tys. mieszkańców. W stosunku do wyborów z 2014 r. liczba takich przypadków wzrosła w 2018 r. o 77%. Wydaje się, że obowiązujące prawo wyborcze, w szczególności art. 418 § 1 (podział gmin na jednomandatowe okręgi wyborcze), art. 434 § 1 i 2 (zasady organizacji wyborów w przypadku zgłoszenia liczby kandydatów równej liczbie mandatów do obsadzenia) i art. 478 § 2 (tryb zgłaszania kandydatów na wójta lub burmistrza) Kodeksu wyborczego, w połączeniu z uwarunkowaniami lokalnej rywalizacji wyborczej, może sprzyjać powstawaniu zjawiska niekonkurencyjnych wyborów, które skutkują m.in. spadki…
Retail banking in the aftermath of the financial crisis
2018
This thesis considers the effects of the global financial crisis that started in 2008 on the retail banking environment and on banks’ behavior during and in the aftermath of the crisis. The thesis consists of an introductory chapter and three empirical articles that use unique datasets on Finnish cooperative banks. The introductory chapter provides background and an overview of the thesis and considers the effects of the crisis on retail banking from an overall perspective. The empirical articles investigate the roles of a competitive environment, a low interest rate environment, and relationship banking during the crisis and in the post-crisis period. The first article looks at whether the…
Los paisajes de la globalización, la elección de la ciudad-expo 2008. ¿Qué pasa con la gobernanza urbana frente a las estrategias económicas y espaci…
2005
Am 16. Dezember 2004 wählte das Bureau international des expositions (B.I.E.) Spanien und seine Kandidatenstadt, die Metropole Saragossa, als Organisationsland für die nächste internationale Ausstellung „International Exhibition of Zaragoza Spain 2008: Water and Sustainable Development“. Wir analysieren zunächst die Entwicklung "der Wege" der Kandidaturen zur Wahl der Gastgeberstadt der Internationalen Ausstellung 2008, dann greifen wir in einem zweiten Mal den gesamten Vorgang der Ausarbeitung, Begründung und Durchführung der Internationalen Ausstellung 2008 in Saragossa auf im Kontext der Globalisierung neue städtische Formen und Formen des Regierens hervorbringen, indem alle finanziellen…
Phosphorus limitation enhances parasite impact: feedback effects at the population level
2014
Background Nutrient deficiency affects the growth and population dynamics of consumers. Endoparasites can be seen as consumers that drain carbon (C) or energy from their host while simultaneously competing for limiting resources such as phosphorus (P). Depending on the relative demands of the host and the parasite for the limiting nutrient, intensified resource competition under nutrient limitation can either reduce the parasite’s effect on the host or further reduce the fitness of the nutrient-limited host. So far, knowledge of how nutrient limitation affects parasite performance at the host population level and how this affects the host populations is limited. Results We followed the popu…