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Animal Sexuality
Animal sexual behaviour takes many different forms, including within the same species. Common mating or reproductively motivated systems include monogamy, polygyny, polyandry, polygamy and promiscuity. Other sexual behaviour may be reproductively motivated (e.g. sex apparently due to duress or coercion and situational sexual behaviour) or non-reproductively motivated (e.g. homosexual sexual behaviour, bisexual sexual behaviour, cross-species sex, sexual arousal from objects or places, sex with dead animals, etc.). When animal sexual behaviour is reproductively motivated, it is often termed ''mating'' or ''copulation''; for most non-human mammals, mating and copulation occur at oestrus (the most fertile period in the mammalian female's reproductive cycle), which increases the chances of successful impregnation. Some animal sexual behaviour involves competition, sometimes fighting, between multiple males. Females often select males for mating only if they appear strong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphilia
Paraphilia (previously known as sexual perversion and sexual deviation) is the experience of intense sexual arousal to atypical objects, situations, fantasies, behaviors, or individuals. It has also been defined as sexual interest in anything other than a consenting human partner. There is no scientific consensus for any precise border between unusual sexual interests and paraphilic ones. There is debate over which, if any, of the paraphilias should be listed in diagnostic manuals, such as the ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM) or the International Classification of Diseases (ICD). The number and taxonomy of paraphilia is under debate; one source lists as many as 549 types of paraphilia. The DSM-5 has specific listings for eight paraphilic disorders. Several sub-classifications of the paraphilias have been proposed, and some argue that a fully dimensional, spectrum or complaint-oriented approach would better reflect the evidence. Terminology Histor ... [...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 mate under which circumstances. Recognised systems include monogamy, polygamy (which includes polygyny, polyandry, and polygynandry), and 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, but only when arising by modification of sexual function). Mixed mating systems, in which plants use two or even all three mating s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Behavioural Ecology
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when studying animal behaviors: What are the proximate causes, ontogeny, 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 frequently than less loud birds—thus sending mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sociobiology
Sociobiology is a field of biology that aims to examine and explain social behavior in terms of evolution. It draws from disciplines including psychology, ethology, anthropology, evolution, zoology, archaeology, and population genetics. Within the study of human societies, sociobiology is closely allied to evolutionary anthropology, human behavioral ecology, evolutionary psychology, and sociology. Sociobiology investigates social behaviors such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. It argues that just as selection pressure led to animals evolving useful ways of interacting with the natural environment, so also it led to the genetic evolution of advantageous social behavior. While the term "sociobiology" originated at least as early as the 1940s, the concept did not gain major recognition until the publication of E. O. Wilson's book '' Sociobiology: The New Synthesis'' in 1975. The new field quickly became the subject of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tool Use By Animals
Tool use by animals is a phenomenon in which an animal uses any kind of tool in order to achieve a goal such as acquiring food and water, grooming, defence, communication, recreation or construction. Originally thought to be a skill possessed only by humans, some tool use requires a sophisticated level of cognition. There is considerable discussion about the definition of what constitutes a tool and therefore which behaviours can be considered true examples of tool use. A wide range of animals, including mammals, birds, fish, cephalopods, and insects, are considered to use tools. Primates are well known for using tools for hunting or gathering food and water, cover for rain, and self-defence. Chimpanzees have often been the object of study in regard to their usage of tools, most famously by Jane Goodall, since these animals are frequently kept in captivity and are closely related to humans. Wild tool use in other primates, especially among apes and monkeys, is considered rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Competition (biology)
Competition is an interaction between organisms or species in which both require a resource that is in limited supply (such as food, water, or territory). Competition lowers the fitness of both organisms involved since the presence of one of the organisms always reduces the amount of the resource available to the other. In the study of community ecology, competition within and between members of a species is an important biological interaction. Competition is one of many interacting biotic and abiotic factors that affect community structure, species diversity, and population dynamics (shifts in a population over time). There are three major mechanisms of competition: interference, exploitation, and apparent competition (in order from most direct to least direct). Interference and exploitation competition can be classed as "real" forms of competition, while apparent competition is not, as organisms do not share a resource, but instead share a predator. Competition among membe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearson Education
Pearson Education is a British-owned education publishing and assessment service to schools and corporations, as well for students directly. Pearson owns educational media brands including Addison–Wesley, Peachpit, Prentice Hall, eCollege, Longman, Scott Foresman, and others. Pearson is part of Pearson plc, which formerly owned the ''Financial Times''. It claims to have been formed in 1840, with the current incarnation of the company created when Pearson plc purchased the education division of Simon & Schuster (including Prentice Hall and Allyn & Bacon) from Viacom and merged it with its own education division, Addison-Wesley Longman, to form Pearson Education. Pearson Education was rebranded to Pearson in 2011 and split into an International and a North American division. Although Pearson generates approximately 60 percent of its sales in North America, it operates in more than 70 countries. Pearson International is headquartered in London, and maintains offices across Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford University Press
Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books by decree in 1586, it is the second oldest university press after Cambridge University Press. It is a department of the University of Oxford and is governed by a group of 15 academics known as the Delegates of the Press, who are appointed by the vice-chancellor of the University of Oxford. The Delegates of the Press are led by the Secretary to the Delegates, who serves as OUP's chief executive and as its major representative on other university bodies. Oxford University Press has had a similar governance structure since the 17th century. The press is located on Walton Street, Oxford, opposite Somerville College, in the inner suburb of Jericho. For the last 500 years, OUP has primarily focused on the publication of pedagogical texts and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Fertilization
Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction. For internal fertilization to happen there needs to be a method for the male to introduce the sperm into the female's reproductive tract. Most taxa that reproduce by internal fertilization are gonochoric. In mammals, reptiles, and certain other groups of animals, this is done by copulation, an intromittent organ being introduced into the vagina or cloaca. In most birds, the cloacal kiss is used, the two animals pressing their cloacas together while transferring sperm. Salamanders, spiders, some insects and some molluscs undertake internal fertilization by transferring a spermatophore, a bundle of sperm, from the male to the female. Following fertilization, the embryos are laid as eggs in oviparous organisms, or continue to develop inside the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrous Cycle
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases, otherwise known as "rest" phases, or by pregnancies. Typically, estrous cycles repeat until death. These cycles are widely variable in duration and frequency depending on the species.Bronson, F. H., 1989. Mammalian Reproductive Biology. University of Chicago Press, Chicago, IL, USA. Some animals may display bloody vaginal discharge, often mistaken for menstruation. Many mammals used in commercial agriculture, such as cattle and sheep, may have their estrous cycles artificially controlled with hormonal medications for optimum productivity. The male equivalent, seen primarily in ruminants, is called rut. Differences from the menstrual cycle Mammals share the same reproductive system, including the regulatory hypothalamic system t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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