Sexual selection in humans
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Brain Sci. Kurzban R. Alas poor evolutionary psychology: Washburn S, Lancaster C. The evolution of hunting. Chicago, IL: Aldine Press.
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Lovejoy CO. The origin of man. Evolution of the human mating system. Harvard University Press. Chapais B. Monogamy, strongly bonded groups, and the evolution of human social structure.
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Gray PB. Evolution and human sexuality.
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Symons D. The evolution of human sexuality.
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Schmitt DP. Universal sex differences in the desire for sexual variety: Betzig LL. Despotism and differential reproduction: Aldine Publishing Company. Hrdy SB. Raising Darwin's consciousness—female sexuality and the prehominid origins of patriarchy. Short RV. Sexual selection and its component parts, somatic and genital selection, as illustrated Sexual selection in humans man and the great apes.
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Morris D. The naked ape: McGraw Hill. Human evolution and the chimpanzee referential doctrine. In Annual review of anthropology Sexual selection in humans, vol. Palo Alto, CA: Annual Reviews. The importance of physical strength to human males. Sex at dawn: Barash DP. Out of Eden: Sexual selection and the evolution of visually conspicuous sexually dimorphic traits in male monkeys, apes, Sexual selection in humans human beings. Thompson CL. Non-monogamous copulations and potential within-group mating competition in white-faced saki monkeys Pithecia pithecia.
Maintenance of multifemale social organization in a group of Nomascus concolor at Wuliang Mountain, Yunnan, China. Are badges of status adaptive in large complex primate groups? Evolution of multilevel social systems in nonhuman primates and humans.
Swedell L, Plummer T.
Sexual selection is an important mechanism of natural selection which may not get enough attention in basic biology courses. The idea dates back to Darwin, who dedicated over half of one of his books The Descent of Man and Selection in Relation to Sex Sexual selection in humans the subject. The concept of natural selection is often associated with some kind of struggle to survive. Some individuals in a population do better than others and so have more offspring; standard examples might be prey outrunning a predator or vice versa or bacteria developing resistance to an antibiotic. If the reason for their success is heritable i. Sexual selection in humans is one straightforward interpretation of 'survival of the fittest', but restricting our understanding of natural selection to these sorts of cases would be an unfortunate oversimplification. Sexy milf masturbates on cam Humans in Sexual selection.
Sexual selection in humans A papionin multilevel society as a model for hominin social evolution. Costs and benefits of fat-free muscle mass in men: Paternal investment and the human mating system.
Processes 5145— Cuckolded fathers rare in human populations.Radiculopatia
Anderson KG. How well does paternity confidence match actual paternity? Evidence from worldwide nonpaternity rates. The mating system of foragers in the standard cross-cultural sample.
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Hames R. Costs and benefits of monogamy and polygyny for Yanomamo women.
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Evolutionary history of partible paternity in lowland South America. USA19 —19 Barker M. This is my partner, and this is my partner's partner: Sexual hookup culture: Primeval kinship: The human community as a primate society.
Sexual selection in humans and human evolution. Gavrilets S. Human origins and the transition from promiscuity to pair-bonding. USA— The evolution of social monogamy in mammals.
Beyond the nuclear family: Means, variances, and ranges in Sexual selection in humans success: Variance in male lifetime reproductive success and estimation of the degree of polygyny in a primate. Sexual selection and reproductive careers in mandrills Mandrillus sphinx. Sexual dimorphisms and breeding systems in pinnipeds, ungulates, Adelgazar 10 kilos, and humans.
In Evolutionary biology and human social behavior: North Scituate, MA: Duxbury Press. MacDonald KB. The establishment and maintenance of socially imposed mongamy in Western Europe. Politics Life Sci. When choosy individuals show a sufficiently strong aversion to unpopular individuals large bthe equilibrium Sexual selection in humans unstable regardless of the properties of decorative individuals, and exaggerated traits and preferences evolve eventually.
However, as shown in appendix C, the equilibrium is stable provided both choosy and decorative individuals have the ideal trait that lies between the average trait and the average popular trait, i.
Figure 1. The stability condition of the equilibrium is shown in the ab -parameter space. The equilibrium is Sexual selection in humans in the area covered by the grey pentagon.
Each symbol indicates the parameter condition of ab in figure 2.
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Next, we consider a cultural mating preference for a genetic trait. Third, we consider a cultural mating preference for a trait that is affected by both genes and Sexual selection in humans. In this model, we assume the order of life-history events such as i birth, ii genetic trait expression, iii viability selection, iv trait modification, v mating and vi reproduction.
Fourth, we consider a genetic mating preference for a cultural trait with assumptions as in the second model. Fifth, we consider a genetic mating preference for a genetic trait, which is equivalent to [ 19 ]. Interestingly, the effect of the relative number of choosy individuals on the stability of the equilibrium is opposite to that in the Sexual selection in humans model.
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Ever since the time of Darwin [ 1 ], human sexual selection has been hotly debated but, unfortunately, many arguments are theoretically invalid and some Sexual selection in humans simply wrong. For example, although sexual selection should increase the La buena dieta dimorphism of the target trait [ 19 ], sexual selection theory has been applied to many sexually Sexual selection in humans human traits abilitiessuch as bipedalism, intelligence, creativity, language, art and music [ 42 — 44 ].
As mate choice cannot evolve if it is costly without compensating benefits [ 45 ], and both male and female choosiness should be costly in semi-monogamous human populations because of mate competition, a direct or indirect benefit of choosiness Sexual selection in humans counterbalances cost is necessary for the evolution of preferences.
Although choosy individuals may obtain a benefit if the trait honestly signals the bearers' quality, costly preferences never evolve unless there is a mechanism that maintains the honesty of signals, such as resistance to parasites [ 46 ], mutation bias [ Sexual selection in humans ] and a disagreement between fertility and viability optimums of the trait [ 19 ].
Therefore, even if a human-specific trait seems to contribute to mate acquisition, it cannot be concluded that the trait evolved through sexual selection.
Nevertheless, we cannot simply consider that sexual selection has had little effect on human evolution because human behaviour is often culturally transmitted, which may change the results of general sexual Adelgazar 15 kilos theories that assume genetic traits and preferences. Although humans adopt various social learning strategies [ 47 ], the most often observed tendencies may be success bias copying successful individuals and conformist bias copying the majoritywhich may have evolved as an adaptation to temporally and spatially varying environments [ 4849 ].
Sexual selection in humans has also been assumed that there is a restriction on modifying the plain genetic trait i. Note that when a trait is culturally transmitted, reproductive success of individuals does not directly affect the generational change of the trait, but we can regard the process as sexual selection because mating success of individuals has the main influence on the trait evolution.
The presence of a unique equilibrium Sexual selection in humans been demonstrated where Sexual selection in humans the average trait of the decorative sex and the most preferable trait for the choosy sex are plain.
Therefore, when this equilibrium is stable, the trait never evolves to be exaggerated. In other words, exaggerated traits and peculiar preferences can be observed only when sexual selection destabilizes the equilibrium favoured by natural non-sexual selection. However, the equilibrium is always stable, provided that both the choosy and decorative sexes have the ideal trait that lies between the average trait and Sexual selection in humans average popular trait average trait of individuals with a mate.
In other words, a strong aversion to, or high tolerance of, unsuccessful individuals is necessary for exaggerated traits and peculiar preferences to evolve through cultural sexual selection.
Sexual selection in humans This result is unchanged even if we assume that either the trait or the preference is genetically transmitted. The most important difference between genetic and cultural transmission is the restriction on the range of trait and preference values in the next generation time step. When the trait or the preference is genetically transmitted, it should lie within a certain range in the next generation, while there is Sexual selection in humans restriction in cultural transmission.
Therefore, we can suppose that genetic traits and preferences are less likely to be Sexual selection in humans peculiar compared with cultural traits. In humans, peculiar mating preferences, such as those for small feet foot binding or long necks neck ringsare sometimes observed, and these may be transmitted culturally. On the other hand, many globally observed mating preferences, such as male preferences for female traits indicating reproductive capacity, are probably genetic instinctive and can be regarded as the equilibrium in genetic models [ 19 ].
In short, irrational preferences may seldom evolve genetically but sometimes arise culturally and, therefore, it is important Sexual selection in humans dismiss the preconception that every human mating preference aims at gaining good genes or a direct benefit.
This bias may cause the coevolution of exaggerated traits and peculiar preferences because a strong aversion to unsuccessful individuals destabilizes the equilibrium.
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In other words, once a trait accidentally becomes unpopular, it would be more unpopular in the next time step because individuals dislike unpopular traits, which favours exaggerated traits that Sexual selection in humans dissimilar to the unpopular trait. It should be noted that this acceleration occurs regardless of any learning bias of the decorative sex if the choosy sex has a sufficiently strong aversion to unpopular traits.
When individuals of the choosy sex are Sexual selection in humans and prefer the unpopular traits to avoid mate competition with other individuals b is smallthe equilibrium can also be unstable.
A similar destabilization occurs when the decorative sex has sympathy for unsuccessful individuals and thus expresses similar traits to them a is small. In these cases, the destabilization is more likely Sexual selection in humans occur when Sexual selection in humans opposite sex prefers popular traits, i. Interestingly, the destabilization can occur even when both choosy and decorative sexes have the ideal trait that lies between the average popular and unpopular traits i.
In other words, even when male and female ideal traits are not extreme, the joint acceleration of trait and preference can occur if there Sexual selection in humans a large sexual difference in ideal traits. References Andersson.
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Download all figures. Some hypotheses about the evolution of the human brain argue that it is a sexually selected trait, as it would not confer enough fitness in itself relative to its high maintenance costs a quarter to a fifth of the energy and oxygen consumed by a human.
Sexual selection's role in human evolution cannot be definitively established, as features may result from an equilibrium among competing selective pressures, some involving sexual selection, others natural selectionand others pleiotropy.
Richard Dawkins argued that. Charles Darwin described sexual selection as depending on "the advantage which certain individuals have over others of the same sex and species, solely in respect of reproduction". Charles Darwin conjectured that the male beard, as well as the hairlessness of humans compared to nearly all other mammals, Sexual selection in humans results of sexual selection.
He reasoned that since the bodies of females are more nearly hairless, the loss of fur Sexual selection in humans due to Sexual selection in humans selection of females at a remote prehistoric time when males had overwhelming selective power, and that it nonetheless affected males due to genetic correlation between the sexes.
He also hypothesized that contrasts in sexual selection acting along with natural selection were significant factors in the geographical differentiation in human appearance of some isolated groups, as he did not believe that natural selection alone provided a satisfactory answer.
Although not explicit, his observation that in Khoisan women "the posterior part of Sexual selection in humans body projects in a most wonderful manner" known as steatopygia  implies sexual selection for this characteristic.
In The Descent of Man, and Selection in Relation to SexDarwin viewed many physical traits which vary around Sexual selection in humans world as being so trivial to survival  that he concluded some input from sexual selection was required to account for their presence. He noted that variation in these features among the various peoples Sexual selection in humans the world meant human mate-choice criteria would also have to be quite Adelgazar 20 kilos if the focus was similar, and he himself doubted that, citing  reports indicating that ideals of beauty did not, in fact, vary in this way around the world.
Men are generally hairier than women, and Darwin was of the opinion that hairlessness was related to sexual selection; however, several other explanations have been advanced to explain human hairlessnessa leading one is loss of body hair to facilitate sweating. Indicating that a trait is under sexual selection can be difficult to prove through correlational methods, as characters may result from different selective pressures, some involving sexual selection, Sexual selection in humans natural selection, and some may be accidental and due to pleiotropy.
For example, monogamous primates are known to typically exhibit little sexual dimorphism such Sexual selection in humans particularly large males armed with huge canines; however, powerful big-toothed males can provide protection against predators and may be bigger for that reason, rather than in order to Sexual selection in humans confrontations over females.
Males and females differing in size can specialize in, and more fully exploit, different food resources while avoiding competing with each other; furthermore, body size can be useful in avoiding predators and may also be of assistance in securing a mate.
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This is further complicated by the consideration that with larger body size, the skeleton of mammals becomes much more robust and massive relatively speaking. Studies Sexual selection in humans shown the earliest homininae were highly dimorphic and that this tendency lessened over the course of human evolution, suggesting humans have become more monogamous. In contrast, gorillas living in harems exhibit a much Sexual selection in humans sexual dimorphism see: The theory of sexual selection has been used to explain a number of human Sexual selection in humans features.
These include rounded breasts, facial hairpubic hair and penis size. The breasts of primates are flat, yet are able to produce sufficient milk for feeding their young. The breasts of non-lactating human females are filled with fatty tissue and not milk. Thus it has been suggested the rounded female breasts are signals of fertility. Since a human Adelgazar 72 kilos relies on a hydraulic pumping system, erection failure is a sensitive early warning of certain kinds of physical and mental ill health.
Homo has a thicker penis than the other great apesthough it is on average no longer than the chimpanzee 's.
A model study showed displacement Sexual selection in humans semen was directly proportional to the depth of pelvic thrustingas an efficient semen displacement device.
There are a variety of factors that drive sexual selection in humans. Current available research indicates that selection preferences are biologically driven,  that is, by the display of phenotypic traits that can be both consciously and unconsciously evaluated by the opposite sex to determine the Sexual selection in humans and fertility of a potential mate.
Some of the factors that affect how females select their La buena dieta mates for reproduction include voice pitch, facial shape, muscular appearance, Sexual selection in humans height. In a study measuring female attraction to males with varying levels of masculinityAdelgazar 10 kilos was established that women had a general masculinity preferences for men's voices, and Sexual selection in humans the preference for masculinity was Sexual selection in humans in the fertile phase of the menstrual cycle than in the non-fertile phase.
Another factor affecting the selection process is the environment which the person inhabits. In Sexual selection in humans terms, certain environmental conditions may bring about demands for or the disregarding of certain traits. One such example is a preference for males whose facial structure indicates certain hormonal ratios, such as testosterone - cortisol levels sex and stress hormones. Research shows that, for example, in countries Sexual selection in humans varying Human Development Index HDI Sexual selection in humans, females have different preferences for sex-stress hormone ratios, as expressed in the Sexual selection in humans face.
A Royal Society research showed a significant correlation between a measure of societal development and preferences for indication of lower testosterone levels, as manifested in facial features, and the interaction between preferences for testosterone and cortisol.
Humans also have a much larger penis than Sexual selection in humans primates — our close relatives, gorillas and chimps, average 3cm and 8cm, respectively. Rounded breasts and large penises might have served as courtship signals indicative of health and fertility and, like the peacock's tail, they may have been subject to runaway sexual selection. Sexual selection may have also contributed to the evolution of our unusually large brain.
The brain is responsible for about a quarter of our body's consumption of oxygen and glucose. It's also about as big as it can be while fitting through the birth canal; in fact, the female pelvis had to widen during human evolution in order to accommodate a human infant's large skull. Although the brain is capable of amazing feats, it's not necessarily clear that the adaptive benefits from a big brain would justify such extreme costs; after all, other animals with smaller brains can use tools, forage for food and co-ordinate hunting in groups.
However, both the costliness and the extreme size would be in keeping with our exceptionally large brain being a product of sexual selection. In The Mating MindGeoffrey Miller suggested that things like creativity, music, art and humour might have been used as courtship signals by choosy early humans, leading to runaway selection for these signals driving the evolution of a larger and larger brain. So it might be that your sexiest organ is, in fact, between your ears.
July 13, By: Sedeer el-Showk. Aa Aa Aa. An Introduction to Sexual Selection. Email your Friend. February 01, Goodbye! November 16, Divide and conquer: Black to white amateur interracial.
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If the address matches an existing account you will receive an email with instructions to reset your password. If the address matches an existing account you will receive an email with instructions to retrieve your username. Google Scholar. Find Sexual selection in humans author on PubMed. Search for more papers by this author. In humans, both sexes sometimes show peculiar mating preferences that do not appear to increase their fitness either directly Sexual selection in humans indirectly. Sexy slutty teen cheerleaders Selection humans Sexual in.
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