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Frequency-dependent Selection
Frequency-dependent selection is an evolutionary process by which the fitness of a phenotype or genotype depends on the phenotype or genotype composition of a given population. * In positive frequency-dependent selection, the fitness of a phenotype or genotype increases as it becomes more common. * In negative frequency-dependent selection, the fitness of a phenotype or genotype decreases as it becomes more common. This is an example of balancing selection. * More generally, frequency-dependent selection includes when biological interactions make an individual's fitness depend on the frequencies of other phenotypes or genotypes in the population. Frequency-dependent selection is usually the result of interactions between species (predation, parasitism, or competition), or between genotypes within species (usually competitive or symbiotic), and has been especially frequently discussed with relation to anti-predator adaptations. Frequency-dependent selection can lead to polymorphi ... [...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 Darw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Self-incompatibility
Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals (dioecy), and their various modes of spatial (herkogamy) and temporally (dichogamy) separation. SI is best-studied and particularly common in flowering plants, although it is present in other groups, including sea squirts and fungi. In plants with SI, when a pollen grain produced in a plant reaches a stigma of the same plant or another plant with a matching allele or genotype, the process of pollen germination, pollen-tube growth, ovule fertilization, or embryo development is inhibited, and consequently no seeds are produced. SI is one of the most important means of preventing inbreeding and promoting the generation of new genotypes in plants and it is considered one of the causes of the spread and success of angiosperms on Earth. Mechani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrurus Fulvius
''Micrurus fulvius'', commonly known as the eastern coral snake, Behler John L.; King, F. Wayne (1979). ''The Audubon Society Field Guide to North American Reptiles and Amphibians''. New York: Alfred A. Knopf. 743 pp., 657 color plates. LCCCN 79-2217. . (''Micrurus fulvius'', p. 681 + Plates 617, 618). common coral snake, American cobra, Wright, Albert Hazen; Wright, Anna Allen (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates. (7th printing, 1985). 1,105 pp. (in 2 volumes). . (''Micrurus fulvius'', pp. 890–897, Map 63, Figures 256–257). and more, is a species of highly venomous coral snake in the family Elapidae. The species is endemic to the southeastern United States. It should not be confused with the scarlet snake (''Cemophora coccinea'') or scarlet kingsnake (''Lampropeltis elapsoides''), which are harmless mimics. No subspecies are currently recognized. Description ''M. fulvius'' is generally less tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lampropeltis Elapsoides
The scarlet kingsnake or scarlet milk snake (''Lampropeltis elapsoides'') is a species of kingsnake found in the southeastern and eastern portions of the United States. Like all kingsnakes, they are nonvenomous. They are found in pine flatwoods, hydric hammocks, pine savannas, mesic pine-oak forests, prairies, cultivated fields, and a variety of suburban habitats; not unusually, people find scarlet kingsnakes in their swimming pools, especially during the spring. Until recently, and for much of the 20th century, scarlet kingsnakes were considered a subspecies of the milk snake; however, Pyron and Bubrink demonstrated the phylogenetic distinction of this species and its closer relationship to the mountain kingsnakes of the southwestern United States. These largely fossorial snakes are the smallest of all the species within the genus ''Lampropeltis'', usually ranging from at maturity. The maximum recorded length is in Jonesboro, AR . Hatchlings range in size from . Taxonomy T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batesian Mimicry
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on butterflies in the rainforests of Brazil. Batesian mimicry is the most commonly known and widely studied of mimicry complexes, such that the word mimicry is often treated as synonymous with Batesian mimicry. There are many other forms however, some very similar in principle, others far separated. It is often contrasted with Müllerian mimicry, a form of mutually beneficial convergence between two or more harmful species. However, because the mimic may have a degree of protection itself, the distinction is not absolute. It can also be contrasted with functionally different forms of mimicry. Perhaps the sharpest contrast here is with aggressive mimicry where a predator or parasite mimics a harmless species, avoiding detection and improvin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Müllerian Mimicry
Müllerian mimicry is a natural phenomenon in which two or more well-defended species, often foul-tasting and sharing common predators, have come to mimic each other's honest warning signals, to their mutual benefit. The benefit to Müllerian mimics is that predators only need one unpleasant encounter with one member of a set of Müllerian mimics, and thereafter avoid all similar coloration, whether or not it belongs to the same species as the initial encounter. It is named after the German naturalist Fritz Müller, who first proposed the concept in 1878, supporting his theory with the first mathematical model of frequency-dependent selection, one of the first such models anywhere in biology. Müllerian mimicry was first identified in tropical butterflies that shared colourful wing patterns, but it is found in many groups of insects such as bumblebees, and other animals including poison frogs and coral snakes. The mimicry need not be visual; for example, many snakes share ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aposematism
Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous coloration, sounds, odours, or other perceivable characteristics. Aposematic signals are beneficial for both predator and prey, since both avoid potential harm. The term was coined in 1877 by Edward Bagnall Poulton for Alfred Russel Wallace's concept of warning coloration. Aposematism is exploited in Müllerian mimicry, where species with strong defences evolve to resemble one another. By mimicking similarly coloured species, the warning signal to predators is shared, causing them to learn more quickly at less of a cost. A genuine aposematic signal that a species actually possesses chemical or physical defences is not the only way t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Müllerian Mimicry Among Heliconius Species
{{Disambiguation ...
Müllerian may refer to: *Müllerian mimicry, a type of mimicry or convergence named after Fritz Müller *Müllerian ducts, which enter the cloaca of an embryo (named after Johannes Peter Müller) * Mullerian anomalies are structural anomalies caused by errors in embryonic müllerian duct development *Mixed Müllerian tumor A malignant mixed Müllerian tumor, also known as malignant mixed mesodermal tumor (MMMT) is a cancer found in the uterus, the ovaries, the fallopian tubes and other parts of the body that contains both carcinomatous ( epithelial tissue) and sarc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaly-breasted Munia
The scaly-breasted munia or spotted munia (''Lonchura punctulata''), known in the pet trade as nutmeg mannikin or spice finch, is a sparrow-sized estrildid finch native to tropical Asia. A species of the genus ''Lonchura'', it was formally described and named by Carl Linnaeus in 1758. Its name is based on the distinct scale-like feather markings on the breast and belly. The adult is brown above and has a dark conical bill. The species has 11 subspecies across its range, which differ slightly in size and color. This munia eats mainly grass seeds apart from berries and small insects. They forage in flocks and communicate with soft calls and whistles. The species is highly social and may sometimes roost with other species of munias. This species is found in tropical plains and grasslands. Breeding pairs construct dome-shaped nests using grass or bamboo leaves. The species is endemic to Asia and occurs from India and Sri Lanka east to Indonesia and the Philippines (where it is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Paper Scissors
Rock paper scissors (also known by other orderings of the three items, with "rock" sometimes being called "stone," or as Rochambeau, roshambo, or ro-sham-bo) is a hand game originating in China, usually played between two people, in which each player simultaneously forms one of three shapes with an outstretched hand. These shapes are "rock" (a closed fist), "paper" (a flat hand), and "scissors" (a fist with the index finger and middle finger extended, forming a V). "Scissors" is identical to the two-fingered V sign (also indicating "victory" or "peace") except that it is pointed horizontally instead of being held upright in the air. A simultaneous, zero-sum game, it has three possible outcomes: a draw, a win or a loss. A player who decides to play rock will beat another player who has chosen scissors ("rock crushes scissors" or "breaks scissors" or sometimes "blunts scissors"), but will lose to one who has played paper ("paper covers rock"); a play of paper will lose to a play ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Side-blotched Lizard
The common side-blotched lizard (''Uta stansburiana'') is a species of side-blotched lizard in the family Phrynosomatidae. The species is native to dry regions of the western United States and northern Mexico. It is notable for having a unique form of polymorphism wherein each of the three different male morphs utilizes a different strategy in acquiring mates. The three morphs compete against each other following a pattern of rock paper scissors, where one morph has advantages over another but is outcompeted by the third. Etymology The specific epithet, ''stansburiana'', is in honor of Captain Howard Stansbury of the US Corps of Topographical Engineers, who collected the first specimens while leading the 1849-1851 expedition to explore and survey the Great Salt Lake of Utah. Taxonomy The systematics and taxonomy of the widespread and variable lizards of the genus '' Uta'' is much disputed. Countless forms and morphs have been described as subspecies or even distinct species. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Behavioral Ecology
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for ethology, animal behavior due to ecology, ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined Tinbergen's four questions, four questions to address when studying animal behaviors: What are the proximate causes, ontogeny, Adaption, survival value, and phylogeny of a behavior? If an organism has a trait that provides a selective advantage (i.e., has adaptive significance) in its environment, then natural selection favors it. Adaptive significance refers to the expression of a trait that affects fitness, measured by an individual's reproductive success. Adaptive traits are those that produce more copies of the individual's genes in future generations. Maladaptive traits are those that leave fewer. For example, if a bird that can call more loudly attracts more mates, then a loud call is an adaptive trait for that species because a louder bird mates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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