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Monogamy In Animals
Monogamous pairing in animals refers to the natural history of mating systems in which species pair bond to raise offspring. This is associated, usually implicitly, with sexual monogamy. Monogamous mating Monogamy is defined as a pair bond between two adult animals of the same species – typically of the opposite sex. This pair may cohabitate in an area or territory for some duration of time, and in some cases may copulate and reproduce with only each other. Monogamy may either be short-term, lasting one to a few seasons or long-term, lasting many seasons and in extreme cases, life-long. Monogamy can be partitioned into two categories, social monogamy and genetic monogamy which may occur together in some combination, or completely independently of one another.Ophir, Alexander G., Phelps, Steven M., Sorin, Anna Bess & O. Wolff, J. (2008)Social but not genetic monogamy is associated with greater breeding success in prairie voles/ref> As an example, in the cichlid species '' Variab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mating System
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, 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 ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incidence Of Monogamy
Monogamy ( ) is a form of dyadic relationship in which an individual has only one partner during their lifetime. Alternately, only one partner at any one time (serial monogamy) — as compared to the various forms of non-monogamy (e.g., polygamy or polyamory). The term is also applied to the social behavior of some animals, referring to the state of having only one mate at any one time. A monogamous relationship can be sexual or emotional, but it's usually both. Many modern relationships are monogamous. Terminology The word ''monogamy'' derives from the Greek μονός, ''monos'' ("alone"), and γάμος, ''gamos'' ("marriage").Cf. "Monogamy" in ''Britannica World Language Dictionary'', R.C. Preble (ed.), Oxford-London 1962, p. 1275:''1. The practice or principle of marrying only once. opp. to digamy now ''rare'' 2. The condition, rule or custom of being married to only one person at a time (opp. to polygamy or bigamy) 1708. 3. Zool. The habit of living in pairs, or having ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generally refers to ''Homo sapiens'', the only extant member. Anatomically moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gorilla
Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or five subspecies. The DNA of gorillas is highly similar to that of humans, from 95 to 99% depending on what is included, and they are the next closest living relatives to humans after chimpanzees and bonobos. Gorillas are the largest living primates, reaching heights between 1.25 and 1.8 metres, weights between 100 and 270 kg, and arm spans up to 2.6 metres, depending on species and sex. They tend to live in troops, with the leader being called a silverback. The Eastern gorilla is distinguished from the Western by darker fur colour and some other minor morphological differences. Gorillas tend to live 35–40 years in the wild. The oldest gorilla known is Fatou (b. 1957), who is still alive at the advanced age of 65 years. Gorillas' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative the bonobo was more commonly known as the pygmy chimpanzee, this species was often called the common chimpanzee or the robust chimpanzee. The chimpanzee and the bonobo are the only species in the genus ''Pan''. Evidence from fossils and DNA sequencing shows that ''Pan'' is a sister taxon to the human lineage and is humans' closest living relative. The chimpanzee is covered in coarse black hair, but has a bare face, fingers, toes, palms of the hands, and soles of the feet. It is larger and more robust than the bonobo, weighing for males and for females and standing . The chimpanzee lives in groups that range in size from 15 to 150 members, although individuals travel and forage in much smaller groups during the day. The species lives in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primate
Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including humans). Primates arose 85–55 million years ago first from small terrestrial mammals, which adapted to living in the trees of tropical forests: many primate characteristics represent adaptations to life in this challenging environment, including large brains, visual acuity, color vision, a shoulder girdle allowing a large degree of movement in the shoulder joint, and dextrous hands. Primates range in size from Madame Berthe's mouse lemur, which weighs , to the eastern gorilla, weighing over . There are 376–524 species of living primates, depending on which classification is used. New primate species continue to be discovered: over 25 species were described in the 2000s, 36 in the 2010s, and three in the 2020s. Primates have large bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testes
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosterone. Testosterone release is controlled by the anterior pituitary luteinizing hormone, whereas sperm production is controlled both by the anterior pituitary follicle-stimulating hormone and gonadal testosterone. Structure Appearance Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Scrotal asymmetry, in which one testicle extends farther down into the scrotum than the other, is common. This is because of the differences in the vasculature's anatomy. For 85% of men, the right testis hangs lower than the left one. Measurement and volume The volume of the testicle can be estimated by palpating it and comparing it to ellipsoids of known sizes. Another method is to use cali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silverback
Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or five subspecies. The DNA of gorillas is highly similar to that of humans, from 95 to 99% depending on what is included, and they are the next closest living relatives to humans after chimpanzees and bonobos. Gorillas are the largest living primates, reaching heights between 1.25 and 1.8 metres, weights between 100 and 270 kg, and arm spans up to 2.6 metres, depending on species and sex. They tend to live in troops, with the leader being called a silverback. The Eastern gorilla is distinguished from the Western by darker fur colour and some other minor morphological differences. Gorillas tend to live 35–40 years in the wild. The oldest gorilla known is Fatou (b. 1957), who is still alive at the advanced age of 65 years. Gorillas' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homo Erectus
''Homo erectus'' (; meaning "upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as '' H. heidelbergensis'' and '' H. antecessor'' — with the former generally considered to have been the ancestor to Neanderthals, Denisovans, and modern humans — appear to have evolved from ''H. erectus''. Its specimens are among the first recognizable members of the genus ''Homo''. ''H. erectus'' was the first human ancestor to spread throughout Eurasia, with a continental range extending from the Iberian Peninsula to Java. Asian populations of ''H. erectus'' may be ancestral to '' H. floresiensis'' and possibly to '' H. luzonensis''. The last known population of ''H. erectus'' is '' H. e. soloensis'' from Java, around 117,000–108,000 years ago. ''H. erectus'' had a more modern gait and body proportions, and was the first human species to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australopithecus
''Australopithecus'' (, ; ) is a genus of early hominins that existed in Africa during the Late Pliocene and Early Pleistocene. The genus ''Homo'' (which includes modern humans) emerged within ''Australopithecus'', as sister to e.g. ''Australopithecus sediba''. Also the genera ''Paranthropus'' and ''Kenyanthropus'' emerged within ''Australopithecus''. ''Australopithecus'' is a member of the subtribe Australopithecina, which sometimes also includes ''Ardipithecus'', though the term "australopithecine" is sometimes used to refer only to members of ''Australopithecus''. Species include ''Australopithecus garhi, A. garhi'', ''Australopithecus africanus, A. africanus'', ''Australopithecus sediba, A. sediba'', ''Australopithecus afarensis, A. afarensis, Australopithecus anamensis, A. anamensis, Australopithecus bahrelghazali, A. bahrelghazali'' and ''Australopithecus deyiremeda, A. deyiremeda''. Debate exists as to whether some ''Australopithecus'' species should be reclassified into ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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