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Contest Competition
In ecology, contest competition refers to a situation where available resources, such as food and mates, are utilized only by one or a few individuals, thus preventing development or reproduction of other individuals. It refers to a hypothetical situation in which several individuals stage a contest for which one eventually emerges victorious. Contest competition is the opposite of scramble competition, a situation in which available resources are shared equally among individuals. As contest competition allows the monopolization of resources, offspring will typically always be produced and survive until adulthood independent of the population size, resulting in stable population dynamics. This is in stark contrast to scramble competition which can result in periodic or chaotic population dynamics. The Beverton–Holt model is often used to represent population dynamics arising from contest competition. This model, and a few other well-known population models, can be explicitly derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecology
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and it is not synonymous with environmentalism. Among other things, ecology is the study of: * The abundance, biomass, and distribution of organisms in the context of the environment * Life processes, antifragility, interactions, and adaptations * The movement of materials and energy through living communities * The successional development of ecosystems * Cooperation, competition, and predation within and between species * Patterns of biodiversity and its effect on ecosystem processes Ecology has practical applications in conservation biology, wetland management, natural resource managemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicholson–Bailey Model
The Nicholson–Bailey model was developed in the 1930s to describe the population dynamics of a coupled host-parasitoid system. It is named after Alexander John Nicholson and Victor Albert Bailey. Host-parasite and prey-predator systems can also be represented with the Nicholson-Bailey model. The model is closely related to the Lotka–Volterra model, which describes the dynamics of antagonistic populations (preys and predators) using differential equations. The model uses (discrete time) difference equations to describe the population growth of host-parasite populations. The model assumes that parasitoids search for hosts at random, and that both parasitoids and hosts are assumed to be distributed in a non-contiguous ("clumped") fashion in the environment. In its original form, the model does not allow for stable coexistence. Subsequent refinements of the model, notably adding density dependence on several terms, allowed this coexistence to happen. Equations Derivation The m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scramble Competition
In ecology, scramble competition (or complete symmetric competition or exploitation competition) refers to a situation in which a resource is accessible to all competitors (that is, it is not monopolizable by an individual or group). However, since the particular resource is usually finite, scramble competition may lead to decreased survival rates for all competitors if the resource is used to its carrying capacity. Scramble competition is also defined as " finite resource hatis shared equally amongst the competitors so that the quantity of food per individual declines with increasing population density".Den Berg, V., Rossing, W., and Grasman, J. (2006). "Contest and Scramble Competition and the Carry-Over Effect in Globodera spp. In Potato-Based Crop Rotations Using an Extended Ricker Model". Journal of Nematology, 38(2):210-220. A further description of scramble competition is "competition for a resource that is inadequate for the needs of all, but which is partitioned equally amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraspecific Competition
Intraspecific competition is an interaction in population ecology, whereby members of the same species compete for limited resources. This leads to a reduction in fitness for both individuals, but the more fit individual survives and is able to reproduce. By contrast, interspecific competition occurs when members of different species compete for a shared resource. Members of the same species have rather similar requirements for resources, whereas different species have a smaller contested resource overlap, resulting in intraspecific competition generally being a stronger force than interspecific competition. Individuals can compete for food, water, space, light, mates, or any other resource which is required for survival or reproduction. The resource must be limited for competition to occur; if every member of the species can obtain a sufficient amount of every resource then individuals do not compete and the population grows exponentially. Prolonged exponential growth is rare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speckled Wood (butterfly)
The speckled wood (''Pararge aegeria'') is a butterfly found in and on the borders of woodland areas throughout much of the Palearctic realm. The species is subdivided into multiple subspecies, including ''Pararge aegeria aegeria'', ''Pararge aegeria tircis'', ''Pararge aegeria oblita'', and ''Pararge aegeria insula''. The color of this butterfly varies between subspecies. The existence of these subspecies is due to variation in morphology down a gradient corresponding to a geographic cline. The background of the wings ranges from brown to orange, and the spots are either pale yellow, white, cream, or a tawny orange. The speckled wood feeds on a variety of grass species. The males of this species exhibit two types of mate locating behaviors: territorial defense and patrolling. The proportion of males exhibiting these two strategies changes based on ecological conditions. The monandrous female must choose which type of male can help her reproduce successfully. Her decision is heavi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuterebra Austeni
''Cuterebra austeni'' is a species of new world skin bot flies in the family Oestridae Botflies, also known as warble flies, heel flies, and gadflies, are a family of flies known as the Oestridae. Their larvae are internal parasites of mammals, some species growing in the host's flesh and others within the gut. ''Dermatobia homin .... References Further reading * External links Diptera.infoNCBI Taxonomy Browser, ''Cuterebra austeni'' Oestridae Insects described in 1986 {{Oestroidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Gorilla
The mountain gorilla (''Gorilla beringei beringei'') is one of the two subspecies of the eastern gorilla. It is listed as endangered by the IUCN as of 2018. There are two populations: One is found in the Virunga volcanic mountains of Central/ East Africa, within three National Parks: Mgahinga, in southwest Uganda; Volcanoes, in northwest Rwanda; and Virunga, in the eastern Democratic Republic of Congo (DRC). The other population is found in Uganda's Bwindi Impenetrable National Park. Some primatologists speculate the Bwindi population is a separate subspecies, though no description has been finalized. As of June 2018, there were more than 1,000 individuals. Evolution, taxonomy, and classification Mountain gorillas are descendants of ancestral monkeys and apes found in Africa and Arabia during the start of the Oligocene epoch (34–24 million years ago). The fossil record provides evidence of the hominoid primates (apes) found in east Africa approximately 22–32 million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitness (biology)
Fitness (often denoted w or ω in population genetics models) is the quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Darwin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callosobruchus Maculatus
''Callosobruchus maculatus'' is a species of beetles known commonly as the cowpea weevil or cowpea seed beetle.Tran, B. M. D. and P. F. Credland. (1995)Consequences of inbreeding for the cowpea seed beetle, ''Callosobruchus maculatus'' (F.) (Coleoptera: Bruchidae).''Biological Journal of the Linnean Society'' 56 483-503. It is a member of the leaf beetle family, Leaf beetle, Chrysomelidae, and not a true weevil. This common pest (organism), pest of stored legumes has a cosmopolitan distribution, occurring on every continent except Antarctica.Cowpea weevil (''Callosobruchus maculatus'' (Fabricius, 1775)). PaDIL. The beetle most likely originated in West Africa and moved around the globe with the trade of legumes and other crops. As onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braconidae
The Braconidae are a family of parasitoid wasps. After the closely related Ichneumonidae, braconids make up the second-largest family in the order Hymenoptera, with about 17,000 recognized species and many thousands more undescribed. One analysis estimated a total between 30,000 and 50,000, and another provided a narrower estimate between 42,000 and 43,000 species. Classification The Braconidae are currently divided into about 47 subfamilies and over 1000 genera, which include ''Aerophilus'', ''Aleiodes'', '' Apanteles'', ''Asobara'', '' Bracon'', ''Cenocoelius'', '' Chaenusa'', ''Chorebus'', '' Cotesia'', '' Dacnusa'', '' Diachasma'', ''Microgaster'', ''Opius'', ''Parapanteles'', '' Phaenocarpa'', ''Spathius'', and ''Syntretus.'' These fall into two major groups, informally called the cyclostomes and noncyclostomes. In cyclostome braconids, the labrum and the lower part of the clypeus are concave with respect to the upper clypeus and the dorsal margin of the mandibles. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scramble Competition
In ecology, scramble competition (or complete symmetric competition or exploitation competition) refers to a situation in which a resource is accessible to all competitors (that is, it is not monopolizable by an individual or group). However, since the particular resource is usually finite, scramble competition may lead to decreased survival rates for all competitors if the resource is used to its carrying capacity. Scramble competition is also defined as " finite resource hatis shared equally amongst the competitors so that the quantity of food per individual declines with increasing population density".Den Berg, V., Rossing, W., and Grasman, J. (2006). "Contest and Scramble Competition and the Carry-Over Effect in Globodera spp. In Potato-Based Crop Rotations Using an Extended Ricker Model". Journal of Nematology, 38(2):210-220. A further description of scramble competition is "competition for a resource that is inadequate for the needs of all, but which is partitioned equally amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteromalidae
The Pteromalidae are a very large family of mostly parasitoid wasps, with some 3,450 described species in about 640 genera (the number was greater, but many species and genera have been reduced by synonymy in recent years). The subfamily-level divisions of the family are highly contentious and unstable, and the family is thought to be "artificial", composed of numerous, distantly related groups (polyphyletic). Accordingly, details of their life histories range over nearly the entire range possible within the Chalcidoidea, though the majority are (as with most chalcidoids) parasitoids of other insects. They are found throughout the world in virtually all habitats, and many are important as biological control agents. The oldest known fossil is known from the Early Cretaceous. In essence, a "pteromalid" is any member of the Chalcidoidea that has five-segmented tarsi and does not have the defining features of any of the remaining families with five-segmented tarsi. It is highly prob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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