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Polygyny Threshold Model
The polygyny threshold model is an evolutionary explanation of polygyny, the mating of one male of a species with more than one female. The model shows how females may gain a higher level of biological fitness by mating with a male who already has a mate. The female makes this choice despite other surrounding males because the choice male's genetics, territory, food supply, or other important characteristics are better than those of his competitors, even with two females on the territory. Graphical depiction The graphical depiction of the model presented in Gordon Orians' 1969 paper is often used to explain the concept. The graph shows two curves on a graph of biological fitness versus environmental quality. Environmental quality refers to the quality of the male's territory. The left curve, labeled monogamous, is the perceived biological fitness for a female entering into a monogamous relationship with a given male. The right curve, labeled bigamous, shows the fitness of the same ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Reed Warbler
The great reed warbler (''Acrocephalus arundinaceus'') is an insectivorous bird in the family Acrocephalidae. It is a medium-sized passerine bird and the largest of the European warblers. It breeds throughout mainland Europe and the Western Palearctic and migrates to sub-Saharan Africa in the winter. It favours reed beds during the breeding season, while living in reed beds, bush thickets, rice fields, and forest clearings during the winter. It exhibits relatively low sexual dimorphism, and the sexes are similar in appearance. This species mates both polygynously and monogamously. Taxonomy The great reed warbler was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his ''Systema Naturae''. He placed it with the thrushes in the genus '' Turdus'' and coined the binomial name ''Turdus arundinaceus''. He specified the type locality as Northern Europe. Linnaeus based his entry on the ''Turdus musicus palustris'' or ''Bruch Beiden Rohr D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mating Systems
A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mating, mate under which circumstances. Recognised systems include Monogamy in animals, monogamy, Animal sexual behaviour#Polygamy, polygamy (which includes Polygyny in animals, polygyny, Polyandry in animals, polyandry, and polygynandry), and Promiscuity#Other animals, promiscuity, all of which lead to different mate choice outcomes and thus these systems affect how sexual selection works in the species which practice them. In plants, the term refers to the degree and circumstances of outcrossing. In human sociobiology, the terms have been extended to encompass the formation of relationships such as marriage. In plants The primary mating systems in plants are outcrossing (cross-fertilisation), autogamy (self-fertilisation) and apomixis (asexual reproduction without fertilization, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Fidelity
Infidelity (synonyms include non-consensual non-monogamy, cheating, straying, adultery, being unfaithful, two-timing, or having an affair) is a violation of a couple's emotional or sexual exclusivity that commonly results in feelings of anger, sexual jealousy, and rivalry. What constitutes infidelity depends on expectations within the relationship. In marital relationships, exclusivity is commonly assumed. Infidelity can cause psychological damage, including feelings of rage and betrayal, depression, low sexual and personal confidence, and even post-traumatic stress disorder. People of both sexes can experience social consequences if their act of infidelity becomes public, but the form and extent of these consequences can depend on the gender of the unfaithful person. Incidence After the Kinsey Reports came out in the early 1950s, findings suggested that historically and cross-culturally, extramarital sex has been a matter of regulation more than sex before marriage. The Kinsey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Psychology
Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regard to the ancestral problems they evolved to solve. In this framework, psychological traits and mechanisms are either functional products of natural selection, natural and sexual selection in human evolution, sexual selection or non-adaptive Spandrel (biology), by-products of other adaptive traits. Adaptationist thinking about Physiology, physiological mechanisms, such as the heart, Lung, lungs, and the liver, is common in evolutionary biology. Evolutionary psychologists apply the same thinking in psychology, arguing that just as the heart evolved to pump blood, the liver evolved to detoxify poisons, and the kidneys evolved to filter turbid fluids there is modularity of mind in that different psychological mechanisms evolved to solve different adaptive problems. These evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypergamy
Hypergamy (colloquially referred to as "dating up" or "marrying up") is a term used in social science for the act or practice of a person dating or marrying a spouse of higher social status than themselves. The antonym "hypogamy" refers to the inverse: marrying a person of lower social class or status (colloquially "marrying down"). The term hypergyny can also be used to describe the overall practice of women marrying up, since the men would be marrying down. Concepts such as hypergamy, hypogamy, and hypergyny could be considered as special cases of mésalliance. By income In a 2016 paper that explored the income difference between couples in 1980 and 2012, researcher Yue Qian noted that the tendency for women to marry men with higher incomes than themselves still persists in the modern era. The observed gender cliff in the distribution of women's share to the household income at 50% can be explained by income hypergamy preferences by both men and women, together with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, education and public engagement and fostering international and global co-operation. Founded on 28 November 1660, it was granted a royal charter by King Charles II and is the oldest continuously existing scientific academy in the world. The society is governed by its Council, which is chaired by the society's president, according to a set of statutes and standing orders. The members of Council and the president are elected from and by its Fellows, the basic members of the society, who are themselves elected by existing Fellows. , there are about 1,700 fellows, allowed to use the postnominal title FRS (Fellow of the Royal Society) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrobates
''Dendrobates'' is a genus of poison dart frogs native to Central and South America. It once contained numerous species, but most originally placed in this genus have been split off into other genera such as '' Adelphobates'', '' Ameerega'', '' Andinobates'', '' Epipedobates'', '' Excidobates'', '' Oophaga'', '' Phyllobates'' and '' Ranitomeya'' (essentially all the brightly marked poison dart frogs; i.e. excluding the duller genera in the family like '' Colostethus'' and '' Hyloxalus''), leaving only five large to medium-sized species in the genus ''Dendrobates''. All the other genera used to be grouped in with ''Dendrobates'' because it was previously thought that all brightly colored poison dart frogs came from the same ancestor but this has since been proven to be incorrect. ''Dendrobates'' and ''Phyllobates'' evolved conspicuous coloration from the same common ancestor but not the same as any of the other genera listed above. There is accumulating evidence that ''Dendrobat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troglodytes Aedon
The northern house wren (''Troglodytes aedon'') is a very small passerine in the wren family Troglodytidae. It is found in southern Canada, the USA and Mexico. It occurs in most suburban areas in its range. It formerly included many subspecies resident in South America and in the Caribbean that are now considered as separate species. The name ''troglodytes'' means "hole dweller", and is a reference to the bird's tendency to disappear into crevices when hunting insects or to seek shelter. Taxonomy The northern house wren was formally described in 1809 by the French ornithologist Louis Pierre Vieillot under the current binomial name ''Troglodytes aedon''. The specific epithet is from the Ancient Greek ''aēdōn'' meaning "nightingale". The type locality was designated as New York City by Harry Oberholser in 1934. An earlier specific name, ''domestica'' in the combination ''Sylvia domestica'', was introduced in 1808 by the American ornithologist Alexander Wilson. This was rarely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red-winged Blackbird
The red-winged blackbird (''Agelaius phoeniceus'') is a passerine bird of the family Icteridae found in most of North America and much of Central America. It breeds from Alaska and Newfoundland south to Florida, the Gulf of Mexico, Mexico, and Guatemala, with isolated populations in western El Salvador, northwestern Honduras, and northwestern Costa Rica. It may winter as far north as Pennsylvania and British Columbia, but northern populations are generally migratory, moving south to Mexico and the Southern United States. Claims have been made that it is the most abundant living land bird in North America, as bird-counting censuses of wintering red-winged blackbirds sometimes show that loose flocks can number in excess of a million birds per flock and the full number of breeding pairs across North and Central America may exceed 250 million in peak years. It also ranks among the best-studied wild bird species in the world. The red-winged blackbird is sexually dimorphic; the male i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny In Animals
Polygyny (; from Neo-Greek , ) is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.Clutton-Brock T.H. (1989). ‘Review lecture: mammalian mating systems.' ''Proceedings of the Royal Society of London''. Series B, Biological Sciences 236: 339–372. Polygyny is typical of one-male, multi-female groupsBoyd, R., & Silk, J. B. (2009). How Humans Evolved (preferably the downloadable pdf version): WW Norton & Company, New York. and can be found in many species including: elephant seal, spotted hyena, gorilla, red-winged prinia, house wren, hamadryas bab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
