In humans normal skin pigmentation is due to a dominant gene

In Colour design: theories and applications ed. Best J, editor. Philadelphia, PA: Woodhead. Biological, cultural, and developmental influences on color preference. Colour vision: physiology and psychophysics. London, UK: Academic Press. Normal and defective colour vision. Haynie HJ, Bowern C. Phylogenetic approach to the evolution of color term systems. Natl Acad. USA13 —13 Spence C. On the psychological impact of food colour.

Flavour 421 Color psychology: effects of perceiving color on psychological functioning in humans. Visible skin color distribution plays a role in the perception of age, attractiveness, and health in female faces. When facial attractiveness is only skin deep. Perception 33— Darwin C. The expression of the emotions in man and animals. London, UK: John Murray. Jablonski NG, Chaplin G. The evolution of human skin coloration. Jablonski NG,Chaplin G. The colours of humanity: the evolution of pigmentation in the human lineage.

B Hunter M. The persistent problem of colorism: skin tone, status, and hierarchy. Endler JA, Mappes J. The current and future state of animal coloration research. Hamilton WD, Zuk M. Heritable true fitness and bright birds: a role for parasites? Science— Guilford T, Dawkins MS. Receiver psychology and the evolution of animal signals.

Elliot AJ. Color and psychological functioning: a review of theoretical and empirical work. Reproducible research in the study of biological coloration. Changes in women's facial skin color over the ovulatory cycle are not detectable by the human visual system. Focal length affects depicted shape and perception of facial images.

Studying primate color: towards visual system-dependent methods. Troscianko J, Stevens M. Image calibration and analysis toolbox — a free software suite for objectively measuring reflectance, colour and pattern. Method Ecol. Brainard DH. Color appearance and color difference specification. In The science of color ed. Shevell SK, editor. Boston, MA: Elsevier. Colour detection thresholds in faces and colour patches.

Perception 42— Oxygenated-blood colour change thresholds for perceived facial redness, health, and attractiveness.

The myth of hidden ovulation: shape and texture changes in the face during the menstrual cycle. Using digital photography to measure animal colouration. Color signal information content and the eye of the beholder: a case study in the rhesus macaque. Color preferences are not universal. Maxims or myths of beauty? A meta-analytic and theoretical review. Facial attractiveness: evolutionary based research. R Soc. B— Facial asymmetry as an indicator of psychological, emotional and physiological distress.

Thornhill R, Gangestad SW. Facial sexual dimorphism, developmental stability, and susceptibility to disease in men and women. Fluctuating asymmetry and physical health among young adults. Facial skin coloration affects perceived health of human faces. Redness enhances perceived aggression, dominance and attractiveness in men's faces.

Cross-cultural effects of color, but not morphological masculinity, on perceived attractiveness of men's faces. Skin colour changes during experimentally-induced sickness. Brain Behav. Evaluation of clinical pallor in the identification and treatment of children with moderate and severe anaemia. Armstrong N, Welsman J. Peak oxygen uptake in relation to growth and maturation in to 17—year-old humans.

Skin blood perfusion and oxygenation colour affect perceived human health. Women's facial redness increases their perceived attractiveness: mediation through perceived healthiness. Perception 45— Non-invasive measurements of skin pigmentation in situ.

Pigment Cell Res. Dietary carotenoids contribute to normal human skin color and UV photosensitivity. Miyamura Y, et al. Regulation of human skin pigmentation and responses to ultraviolet radiation. Pigment Cell Melanoma Res. Carotenoid and melanin pigment coloration affect perceived human health.

Color 3D bodies and judgements of human female attractiveness. Fruit over sunbed: carotenoid skin coloration is found more attractive than melanin coloration. You are what you eat: within-subject increases in fruit and vegetable consumption confer beneficial skin-color changes.

It is all in the face: carotenoid skin coloration loses attractiveness outside the face. Color homogeneity and visual perception of age, health, and attractiveness of female facial skin. Coloration in different areas of facial skin is a cue to health: the role of cheek redness and periorbital luminance in health perception. Body Image 1757— Aspects of facial contrast decrease with age and are cues for age perception.

Russell R. Sex, beauty, and the relative luminance of facial features. Perception 32— A sex difference in facial contrast and its exaggeration by cosmetics. Perception 38— Why cosmetics work. Jones AL. Cosmetics alter biologically-based factors of beauty: evidence from facial contrast.

Guéguen N. Does red lipstick really attract men? An evaluation in a bar. Do cosmetics enhance female Caucasian facial attractiveness? Cosmetics: they influence more than Caucasian female facial attractiveness. Revisiting the red effect on attractiveness and sexual receptivity: No effect of the color red on human mate preferences. Elliot AJ, Niesta D. Romantic red: red enhances men's attraction to women. Color Res. Dressed for sex: red as a female sexual signal in humans. Guéguen N, Jacob C. Color and cyber-attractiveness: red enhances men's attraction to women's internet personal ads.

Strategic sexual signals: Women's display versus avoidance of the color red depends on the attractiveness of an anticipated interaction partner. Red and romantic rivalry: viewing another woman in red increases perceptions of sexual receptivity, derogration, and intentions to mate-guard.

Prokop P, Pazda AD. Women's red clothing can increase mate-guarding from their male partner. Distinguishing between perceiver and wearer effects in clothing color-associated attributions. Red, rank, and romance in women viewing men. The influence of red on impression formation in a job application context. Emotion 37— Kramer RSS. The red power less tie: perceptions of political leaders wearing red.

Red enhances women's attractiveness to men: first evidence suggesting universality. Young SG. The effect of red on male perceptions of female attractiveness: moderation by baseline attractiveness of female faces. Schwarz S, Singer M. Romantic red revisited: red enhances men's attraction to young, but not menopausal women. Timing and probability of ovulation in relation to sex skin swelling in wild West African chimpanzees, Pan troglodytes verus.

Baboon sexual swellings: information content of size and color. Sexual swellings in wild white-handed gibbon females Hylobates lar indicate probability of ovulation. Sexual skin color contains information about the timing of the fertile phase in free-ranging Macaca mulatta.

Signal content of red facial coloration in female mandrills Mandrillus sphinx. Hormone profiles and reproductive characteristics in wilde female Japanese macaques Macaca fuscata. Skin color preference, sexual dimorphism and sexual selection: a case of gene-culture co-evolution? Racial Stud. McGuinness BW. Skin pigmentation and the menstrual cycle.

Female facial attractiveness increases during the fertile phase of the cycle. Women's attractiveness changes with estradiol and progesterone across the ovulatory cycle. Bobst C, Lobmaier JS. Men's preference for the ovulating female is triggered by subtle face shape differences. Is preference for ovulatory female's faces associated with men's testosterone levels?

The normal menstrual cycle in women. Thornton MJ. The biological action of estrogens on the skin. Estrogen and skin. Oestrogen functions in skin and skin appendages. Expert Opin. Law Smith MJ, et al. Facial appearance is a cue to oestrogen levels in women.

Testosterone-to-estradiol ratio is associated with female facial attractiveness. Does a woman's skin color indicate her fertility level? Preliminary findings.

Brincat MP. Hormone replacement therapy and the skin. Maturitas 35— Influence of female reproductive hormones on local thermal control of skin blood flow. Cutaneous vascular changes in women in reference to the menstrual cycle and ovariectomy. Facial coloration tracks changes in women's estradiol. The fact that depigmented skin evolved independently in the ancestors of modern Europeans and East Asians suggests that at least two and probably more distinct genetic mutation events occurred and that multiple loci underwent positive selection in these two regions receiving relatively low levels of UVB [ 78 — 80 ].

The most likely reason for this was that it was associated with a loss of skin pigment that favoured vitamin D production under conditions of low UVB [ 697881 ]. Depigmented skin also evolved independently in Homo neanderthalensis [ 82 ] probably for the same reason. There has been a cause and effect relationship between UVR and skin pigmentation in human evolution, and skin colour phenotypes have been modified under the action of natural selection to maintain an optimum balance between photoprotection and photosynthesis over spatially varying conditions of UVR.

Skin colour thus evolved as the product of two opposing clines, one emphasizing dark pigmentation and photoprotection against high loads of UVA and UVB near the equator, the other favouring depigmented skin to promote seasonal, UVB-induced photosynthesis of vitamin D 3 nearer the poles [ 60 ]. Intermediate latitudes with seasonally high loads of UVB favoured the evolution of people with intermediate colour capable of tanning [ 8485 ]. The most important points to reinforce here are that the geographical gradient of human skin colour evolved under the influence of natural selection, and that very similar skin colour phenotypes dark, light and intermediate have evolved independently numerous times under similar UVR conditions.

Diverse combinations of skin colour genes occurred during the course of prehistory as the combined result of natural selection, gene flow due to migration, and founder effect or genetic drift due to population bottlenecks occurring in the course of dispersal events [ 6286 ].

Indigenous populations of the New World have generally lighter skin colours than those of the Old World, probably because they have vouloir mincir une méthode complète wow resided in their homelands for as long a time and because their adaptations to the environment have been more strongly cultural than biological, as exemplified by the wearing of sewn clothing and the making of shelters [ 212287 ].

Sexual selection does not appear to have been a major influence on the evolution of human skin coloration, but it probably did increase the degree of sexual dimorphism in skin colour in some populations [ 2187 ]. The unexposed skin of females is lighter than that of males in most populations [ 2183 ], possibly because of the greater need of females to produce vitamin D in the skin to absorb and mobilize calcium during pregnancy and lactation.

A persistent, directional preference for lighter-coloured females as marriage partners has been recognized during historic times in some east- and south-Asian cultures, and it is likely that this has contributed to the greater sexual dimorphism in coloration observed [ 2187 ]. Like skin, the coloration of human hair and eyes is determined primarily by the amount and type of melanin produced and stored in melanosomes [ 8889 ]. Iris pigmentation is also influenced by structural features within the eye itself and by the degree of pupillary dilation [ 90 — 92 ].

Although skin coloration varies according to the intensity and seasonality of UVR on a global scale, no such regular geographical pattern is observed with hair and eye coloration [ 93 ]. In fact, little variation in hair and eye coloration occurs in indigenous populations outside of Europe for hair and outside of Europe, North Africa, the Middle East, Central Asia and South Asia for eyes [ 888994 ]. The lack of variation in hair and eye coloration in Africa has been assumed to be caused by the importance of eumelanin in affording protection, as it does in the case of skin coloration, but this has not been empirically established.

Hair and eye coloration appear to have not been under as strong natural selection as skin coloration, and loss of genetic variation at one or more population bottlenecks probably contributed to the patterns of phenotypic variation observed in the hair and irises of modern people [ 95 ].

Scalp hair in most non-European populations is very dark brown, with little phenotypic variation [ 96 ]. Many genes appear to contribute to the dark brown hair colour phenotype [ 8893 ], and the relative importance of different loci is not yet known. The relatively high prevalence of blond hair in Northern Island Melanesia has been traced to the 93C allele of the TYRP1 gene [ 9798 ], which has been dispersed throughout the region in the course of human colonization of the Southwest Pacific.

In Europe, blond hair has been traced to establishment of variation in a regulatory enhancer of the KITLG gene, while red hair is produced by a specific range of variants of the MC1R locus [ 99 — ].

Sexual selection is thought to have influenced the high prevalence of blond- and red-hair phenotypes in Europe [ 93 ], but this has not been established empirically. The nature and coloration of human male facial hair—beards and moustaches—have been a matter of curiosity and speculation, but little formal research [ 16, ]. Male facial hair, manifested as moustaches, cheek hair whiskers and beards, occurs in some male primates and appears to represent secondary sexual characteristics that evolved as amplified visual signals of rank, dominance and attractiveness [ 8].

This supports claims that age-related changes in human beard and moustache coverage and colour on the male face serve as honest signals of age or social dominance [ ], and that they evolved as products of contest competition between males [ ]. Beards augment the effectiveness of human aggressive facial displays, but are rated as ambivalent or unattractive by females []. Until very recently, studies of human iris coloration focused primarily on European populations, where the greatest range and variety of eye colours—from dark brown to pale blue—are found.

Iris colour phenotypes are determined by amounts of melanin and by the ratio of eumelanin to phaeomelanin in the iris, with brown eyes having a higher ratio than light eyes [ 8889 ].

Other categorical eye colours, such as blue, green and hazel, are common in Europe and parts of the Middle East, and Central and South Asia, with Europeans having the lightest eye colours [ 88 ]. The sets of genetic markers associated with variation in iris coloration in Europe, South Asia and East Asia are distinct, and relatively little is known of the combination of evolutionary forces—including natural and sexual selection—that influenced their distribution [ 89 ].

Dark iris coloration is associated with less scattering of intraocular light, a trait that may be protective under conditions of bright sunlight and high UVR. Blue eye coloration, on the other hand, is associated with greater intraocular light scattering and a higher level of melatonin suppression, traits that may have been adaptive under highly seasonal sunshine regimes in northwestern Eurasia [ ].

Blue-eyed women have been found to be preferred by blue-eyed men, possibly as a manifestation of a male adaptation for the detection of extra-pair paternity based on eye colour, as a phenotypically based assurance of paternity [ ]. Arguments for the action of natural and sexual selection on iris colour need to be examined with great care as more data on the genetic basis of the trait are revealed. A recent study showing that the genetic markers associated with iris coloration are also associated with skin and hair pigmentation traits suggests that iris coloration was a pleitropic effect associated with selection on pigmentation genes whose primary effect was skin or hair pigmentation, not iris coloration [ 89 ].

The genetic basis of human coloration is complex because some genetic variants affect all pigmentary systems—skin, hair and eyes—through pleiotropic effects, while others affect only one type [ ] and because different genes and gene combinations can create similar coloration phenotypes. Despite the technical difficulties of such studies, the fascination of humans with their own coloration phenotypes will certainly continue to propel research forward quickly.

Skin, hair and eye coloration in humans is variable, and has been influenced by different combinations of evolutionary forces. Skin coloration has been strongly influenced by natural selection, globally and throughout human prehistory, because of the importance of melanin as a natural sunscreen on naked skin. The role of natural selection in the evolution of hair and eye coloration appears to have been negligible, but genetic bottlenecks followed by sexual selection may have played more significant roles in establishing the patterns of variation recognized outside of Africa.

Regimen de la propiedad en condominio

In recent centuries, humans have migrated faster and over longer distances than during any time in prehistory. Many of these movements have brought people into regions with markedly different solar regimes than their homelands. Many people now live under levels of solar radiation that are much stronger, or much weaker and more seasonal, than those under which their ancestors evolved.

These rapid changes in living circumstances have created significant health problems resulting from too much UVR exposure skin cancer, accelerated ageing of the skin and from too little UVR exposure vitamin D deficiency and its many sequelae that have greatly impacted individual well-being and public health.

Mitigating these problems is now the focus of considerable attention in many health professions [ — ]. Rapid, long-distance migrations have also brought people together from disparate and widely separated places, creating unprecedented and novel opportunities for gene flow. The twenty-first century world contains a sepia rainbow of human skin colours, created from old and new combinations of skin colour—related genetic markers. The effects of these new genetic admixtures on health are not known.

More significant to health and overall human well-being, however, are the problems of social segregation and behavioural bias that are rooted in cultural constructions of skin colour—based race categories [ 87 ]. Humans are visually oriented primates, and our varied colours are badges of our recently shared evolutionary history.

Our skin colours unite us, not divide us. Tim and two anonymous reviewers provided excellent suggestions for improvement of this contribution. We thank Theresa Wilson of Penn State for providing comprehensive support and assistance to our research programme, including the maintenance of our reference library and preparation of this manuscript. The authors contributed equally to the conception and design of this paper and to the drafting and revising of the article for important intellectual content; they also gave the final approval of the version to be published.

National Center for Biotechnology InformationU. Published online May Nina G. Jablonski and George Chaplin. Author information Article notes Copyright and License information Disclaimer.

Accepted Dec 9. This article has been cited by other articles in PMC. Abstract Humans are a colourful species of primate, with human skin, hair and eye coloration having been influenced by a great variety of evolutionary forces throughout prehistory. Keywords: eumelanin, phaeomelanin, ultraviolet radiation, natural selection, sexual selection, genetic drift. Introduction Discussions of the cardinal features of the human lineage usually focus on bipedalism, relative brain size, language and technology, and ignore the remarkable distinctions of the integument and eyes that have figured importantly in human evolution.

Human coloration in context Like most mammals, primates have hair covering most of their bodies. Variation in human skin coloration is mostly a product of natural selection Skin colour as measured by skin reflectance and levels of UVR are highly correlated.

Hair pigmentation reviews

Hair and eye coloration are not under strong natural selection Like skin, the coloration of human hair and eyes is determined primarily by the amount and type of melanin produced and stored in melanosomes [ 8889 ]. Conclusion Skin, hair and eye coloration in humans is variable, and has been influenced by different combinations of evolutionary forces.

Authors' contributions The authors contributed equally to the conception and design of this paper and to the drafting and revising of the article for important intellectual content; they also gave the final approval of the version to be published.

Competing interests We have no competing interests. Funding We received no funding for this study. References 1. Caro T. The colours of extant mammals. Cell Dev. Walsberg GE. Consequences of skin color and fur properties for solar heat gain and ultraviolet irradiance in two mammals. B— The adaptive significance of coloration in mammals. BioScience 55— Body temperature, thermoregulatory behaviour and pelt characteristics of three colour morphs of springbok Antidorcas marsupialis.

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The integument of the odd-nosed colobines. In The natural history of the Doucs and snub-nosed monkeys ed. Jablonski NG, editor. Singapore: World Scientific Publishing Co. The primate palette: the evolution of primate coloration.

Contrasting coloration in terrestrial mammals. Kingdon JS. The role of visual signals and face patterns in African forest monkeys guenons of the genus Cercopithecus. Structural colouration of mammalian skin: convergent evolution of coherently scattering dermal collagen arrays. Sexual swellings advertise female quality in wild baboons.

Nature— Nunn CL. The evolution of exaggerated sexual swellings in primates and the graded-signal hypothesis. Familiarity affects the assessment of female facial signals of fertility by free-ranging male rhesus macaques. Social correlates of testosterone and ornamentation in male mandrills.

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Skin pigmentation disorder name

Mundy N, Kelly J. Investigation of the role of the agouti signaling protein gene ASIP in coat color evolution in primates. Genome 17— Held LI. The evo-devo puzzle of human hair patterning. Jablonski NG. The evolution of human skin and skin color. Wheeler PE. The loss of functional body hair in man: the influence of thermal environment, body form and bipedality. The adaptive response of human skin to the savanna.

Endurance running and the evolution of Homo. Jablonski NG, Chaplin G. The evolution of human skin coloration. Lieberman DE. La rousseur se manifeste chez les humains possédant deux exemplaires d'un allèle récessif d'un gène sur le chromosome 16qui provoque une mutation du gène MC1R. La rousseur varie du bordeaux à l' orange vif, en passant par la couleur cuivrée. Elle est caractérisée par de fortes concentrations du pigment roux phéomélanine et des concentrations assez faibles du pigment sombre eumélanine.

La rousseur est le plus souvent associée à une couleur pâle de la peau, une couleur des yeux plus claire yeux gris ou vertsdes taches de rousseurainsi qu'une sensibilité aux rayonnements ultraviolets [ 2 ]. De nombreuses traces d'écrivains grecs mentionnent les personnes rousses. Un fragment du poète Xénophane décrivait les Thraces comme ayant des yeux bleus et des cheveux roux. Hérodote exposait les Budinis comme étant principalement roux.

En Asie, des personnes rousses ont été trouvées parmi l'ancien peuple Tokharienqui occupait le bassin du Tarim qui fait aujourd'hui partie de Chine. La rousseur apparaît également chez les Polynésienset est banale dans certaines tribus et groupes familiaux.

Dans la culture polynésienne, la rousseur a été traditionnellement vue comme un signe d'ancêtres de grande lignée, et une marque de domination [ 7 ][ 8 ].

Les personnes rousses sont communes parmi les peuples germanique et celtique. Une étude de sur la couleur des cheveux des recrues de l'armée britannique a également trouvé d'importants taux de personnes rousses dans le Pays de Galles et au niveau de la frontière anglo-écossaise [ 13 ]. La rousseur est également assez commune chez les Ashkénazespeut-être causée par le flux d'ADN européen durant de nombreux siècles [ 14 ]bien que Ésaü et David soient décrits dans la Bible comme roux.

En Italie, la rousseur était associée aux Juifs italiens, et Judas était traditionnellement présenté comme roux dans les arts italien et espagnol [ 16 ]. Les écrivains, de Shakespeare à Dickens, identifiaient leurs personnages juifs en leur donnant des cheveux roux [ 17 ].

Le stéréotype selon lequel la rousseur est associée au judaïsme reste toujours présent dans certaines zones d'Europe orientale et de Russie [ 18 ]. Les peuples berbères du Maroc [ 19 ] et du Nord de l' Algérie ont parfois des personnes rousses en leur sein.

Abd al-Rahman I er avait également les cheveux roux, sa mère ayant été une esclave berbère chrétienne. Les cheveux roux peuvent être trouvés parmi les peuples de descendance iraniennecomme les PersansLorsNouristanis et Pachtounes. L'émigration de ces populations du Moyen-Orient, de l'Asie centrale, du Nord de l'Inde et de l'Afrique du Nord a fait évoluer les taux de personnes rousses aux Amériques, en Australie, en Nouvelle-Zélande, en Afrique du Sud, ainsi qu'en d'autres zones d'Afrique et d'Europe.

Les pigments de la peau et des cheveux sont composés de différents types de mélanine. Certaines mutations génétiques ou déficits alimentaires graves bloquent le processus au stade de la phéomélanine, que le corps ne peut pas transformer en eumélanine, entraînant la rousseur. Quelqu'un avec les cheveux bruns aura beaucoup d'eumélanine, tandis qu'une personne aux cheveux cuivrés auburn, blond vénitien, roux aura plus de phéomélanine voire uniquement que de la phéomélanine.

Suivant la luminosité des cheveux roux, on constatera une proportion plus ou moins importante de phéomélanine et d'eumélanine. Les bruns sont entre ces deux catégories. Les gènes codant respectivement les pigments des yeux et des cheveux ne se trouvent pas sur le même chromosome. L'origine des cheveux roux à ne pas confondre avec le blond vénitienqui est un blond à reflets roux fut seulement révélée en Elle est liée au gène MC1R melanocortin-1 receptor qui se trouve sur le chromosome 16 et dont l' allèle non muté ne conduit pas à la rousseur contrairement à cinq autres qui donnent des cheveux roux, une peau pâle et des taches de rousseur.

Cela veut dire aussi qu'il y a au moins cinq origines différentes pour la rousseur et qu'une étude basée seulement sur le phénotype la manifestation du gène, ici la rousseur peut être fausse si elle est généralisée à tous les allèles roux sans distinction.