What Race Has Brown Eyes?

What Race Has Brown Eyes
Brown – Light brown iris can be found in Europe, West Asia, South Asia, Central Asia and among the Americas. With few exceptions, all mammals have brown or darkly-pigmented irises. In humans, brown is by far the most common eye color, with approximately 79% of people in the world having it.

Brown eyes result from a relatively high concentration of melanin in the stroma of the iris, which causes light of both shorter and longer wavelengths to be absorbed. Dark brown eyes are dominant in humans. In many parts of the world, it is nearly the only iris color present. Brown eyes are common in Europe, East Asia, Southeast Asia, Central Asia, South Asia, West Asia, Oceania, Africa and the Americas,

Light or medium-pigmented brown eyes can also be commonly found in South Europe, among the Americas, and parts of Central Asia, West Asia and South Asia,

What type of people have brown eyes?

Why Are Brown Eyes Most Common? – NewView Eye Center Ever found yourself wondering just why brown eyes are so common? As it turns out, there’s a reason ; in fact, it’s estimated that more than 50% of the world’s population has brown eyes. If you think this number’s big, consider this: all humans used to have brown eyes, until an ancestor with a genetic mutation developed what we now know as blue, green, and hazel eyes. There’s a lot more cool info about brown eyes and why they happen. Consider busting out these fun facts during your next trivia night – your friends will be amazed!

Brown eyes are far more common in people who live in warmer climates, This is because excess melanin (which causes the brown colors of the iris) protects the eyes from sunlight. Since warmer climates tend to have more sunlight, this means that brown eyes are more common in cultures near the equator.On the other hand, blue, green, and hazel eyes happen when the iris has less melanin. This characteristic is more common in people who live in colder climates, as they may not get as much sunlight.People with brown eyes are less likely to develop certain eye disorders, like age-related macular disease. Interestingly, scientists are at a loss to explain why that might be. Of course, having brown eyes isn’t an ultimate protection against disease and poor vision; you’ll still need to visit your ophthalmologist.

Want to keep your eyes protected now, no matter the color – for years to come? with ophthalmologist Dr. Jacqueline Griffiths at NewView Eye Center in Reston, VA today.703-834-9777 NewView Eye Center serves the greater Washington, DC metro area. : Why Are Brown Eyes Most Common? – NewView Eye Center

What race has brown hair?

Geographic distribution – Brown-haired individuals predominate in most parts of Europe, In northern and central Europe medium to light brown shades are the most common, while darker shades prevail in the rest of the continent. Brown hair, mostly medium to light brown shades, are also dominant in Australia, Canada, South Africa among White South Africans and the United States among European Americans from the Northern, Central and Eastern European ( British, Scandinavian, Baltic, Dutch / Flemish, German (including Swiss-German and Austrian ), Slovenian, Polish, Ukrainian and Russian ) as well as Southern ( Italian, Spanish, Greek, Portuguese ) and Southeastern European ( Bulgarian, Croatian, Serbian ). Afghan children with brown hair Similarly to blond hair, brown hair occurs commonly among Australian Aboriginal and Melanesian populations. Dark brown hair is predominant in the Mediterranean parts of Europe, the Middle East, North Africa, Central Asia, and South Asia,

Very dark brown hair, easily mistaken for black hair, can be found occasionally in parts of East Asia,
This is also true of Southern Cone of South America ( Chile, Argentina, Uruguay, Paraguay, central-southern Brazil ), Colombia, Andean Region of Venezuela, Costa Rican Central Valley and Puerto Rico,

Dark brown hair also may occasionally be found among Indigenous Siberians and Americans ;(formerly) especially for mostly populations in Southeast Asia due to pigment changes (such as the Philippines, Malaysia and Vietnam ) for example particularly when they are young, as well as in many other groups

Where in Europe do brown eyes come from?

In Europe and Central Asia – A 2019 literature review on eye and hair colors included data on eye colors for countries across Europe and Central Asia. The review used the broad categories of “brown,” “intermediate,” and “blue.” Here are statistics for a few of those countries: * Source: Katsara M-A, et al.

Are colored eyes European?

Why Do Europeans Have So Many Hair and Eye Colors? Peter Frost Université Laval (Canada) and St. Andrews University (Scotland). Most humans have only one hair color and one eye color. Europeans are a big exception: their hair is black but also brown, flaxen, golden, or red; their eyes are brown but also blue, gray, hazel, or green. This diversity reaches a maximum in an area centered on the East Baltic and covering northern and eastern Europe. Why this color diversity? And why only in Europe? Some believe it to be a side effect of natural selection for fairer skin to ensure enough vitamin D at northern latitudes. Yet skin color is weakly influenced by the different alleles for hair color or eye color apart from the ones for red hair or blue eyes.

Some have no effect at all on skin pigmentation.
Others put the cause down to intermixture with Neanderthals.
Yet, according to the mtDNA that has been retrieved, no genetic continuity is discernible between late Neanderthals and early modern Europeans.
Perhaps there was some gene flow between the two groups, but certainly not enough to account for the large number of Europeans with neither black hair nor brown eyes.

For others still, this color diversity arose through random factors: genetic drift, founder effects, relaxation of natural selection, etc. But these factors could not have produced such a wide variety of hair and eye hues in the 35,000 years that modern humans have inhabited Europe.

The hair-color gene (MC1R) has at least 7 alleles that exist only in Europe and the same is probably true for the eye-color gene (OCA2). If we take the hypothesis of a relaxation of selection, nearly a million years would be needed to accumulate this amount of diversity. Moreover, it is odd that the same sort of diversification has evolved at two different genes whose only point in common is to color a facial feature.

Thus, some kind of non-random process seems to have targeted hair and eye color per se, that is, as visible characteristics. But how? And why? For some, including the geneticist Luigi L. Cavalli-Sforza, the answer is sexual selection. This mode of selection intensifies when males outnumber females among individuals ready to mate, or vice versa. Guppy males ( Poecilia reticulata ) caught on a single morning from a single creek (Brooks 2002). Rare-color advantage has been studied mainly in guppies and fruit flies but also occurs in other animals. In addition, a number of bird species exhibit color polymorphisms for which the mode of selection remains unclear. Representative eye colors (Sturm and Frudakis 2004) In other animals, bright colors are usually due to sexual selection. Sometimes the result may be a “color polymorphism” (see box). A potential mate will respond not simply to a bright color but also to a rare one that stands out from the crowd.

By enhancing reproductive success, however, such a color will also become more common and less eye-catching.
Sexual attraction will then shift to less common variants, the eventual result being an equilibrium that maximizes color diversity.
This sort of rare-color advantage has been reported in humans.

An American researcher, Thomas Thelen, prepared three series of slides featuring attractive women: one with 6 brunettes; another with 1 brunette and 5 blondes; and a third with 1 brunette and 11 blondes. Male subjects then had to select the woman in each series they would most prefer to marry.

For the same brunette, preference increased significantly from the first to the third series, i.e., in proportion to the rarity of the brunettes.
This rare-color preference may account for the wide range of human hair and eye phenotypes we see today.
But why is hair and eye color so much more diverse in Europe than elsewhere? Perhaps because sexual selection was much stronger among ancestral Europeans than in other human populations.

Sexual selection intensifies when the “Operational Sex Ratio” (OSR) ceases to be balanced, i.e., when too many of one sex are competing for too few of the other. To understand why this may have happened in ancestral humans, we can examine the demography of present-day hunter-gatherer bands.

Such groups usually develop an OSR imbalance for two reasons: 1) hunting distances are longer and have increased the death rates of young men, typically because game animals are more mobile and/or less numerous per unit of land area; and 2) the cost of providing for a second wife is higher and has reduced the incidence of male polygamy (polygyny), typically because women are procuring less food for themselves through food gathering.

As a rule, OSRs are less balanced further away from the equator. In the Temperate Zone, and even more so in the Arctic, game animals roam over larger territories and gatherable food is less available in winter. The most extreme OSR imbalance occurs among hunting peoples of the “steppe-tundra,” where almost all consumable biomass is in the form of highly mobile and spatially concentrated herbivores such as caribou, reindeer, or muskox. Ecological zones in Europe at the last glacial maximum, ca 18,000 BP, Steppe-tundra is now reduced to fragments along the northern fringes of Eurasia and North America. During the last ice age, however, when modern humans first arrived, the Scandinavian icecap had pushed it farther south onto the plains of Europe. The more intense sunlight, combined with fertile loess soils, created an expanse of steppe-tundra with unusually high bioproductivity, even at the peak of the ice age. Less productive was the Asian steppe-tundra east of the Urals. It was drier, farther north, and largely polar desert, especially at the glacial maximum. Prospects were better for continuous and substantial human settlement on the European portion of this ecological zone. The European steppe-tundra was distinctive in another way. It took in an area that covers almost the same area where hair and eye color is today most diverse. Could this be an imprint left on the human genetic landscape by sexual selection? Perhaps. But more proof is needed. One tantalizing piece of evidence is the possibility that these new hair and eye colors are mildly sex-linked, as would be expected if women were more strongly selected for such characteristics. According to an unpublished British study, non-black-haired and non-brown-eyed individuals have longer second fingers in relation to their fourth fingers. This indicates that the new hair and eye colors are associated with a higher ratio of estrogen to testosterone before birth. Interestingly, blond hair has arisen independently among some Aborigines of central Australia and is more frequent there in women than in men. The Aborigine example points to another avenue for research: populations outside Europe among whom new hair and eye colors seem to have appeared independently. There are a few such cases: blond hair among central Australian Aborigines, brown hair among the Yukhagir of eastern Siberia, and fair hair among some Inuit bands of the western Canadian Arctic. Is hair color less diverse in such populations than in Europeans because sexual selection has been less intense or has acted over a shorter period of time? A final avenue for research might be to extract DNA from skeletal remains in order to chart European MC1R and OCA2 variability over the last ice age. If the sexual selection hypothesis is true, MC1R and OCA2 variability should have developed almost entirely during this time window (c.25,000 – 10,000 BP). References: Abbie, A.A., and W.R. Adey.1953. Pigmentation in a central Australian tribe with special reference to fair-headedness. American Journal of Physical Anthropology 11:339-359. Brooks, R.2002. Variation in female mate choice within guppy populations: population divergence, multiple ornaments and the maintenance of polymorphism. Genetica 116:343-358. Duffy, D.L., N.F. Box, W. Chen, J.S. Palmer, G.W. Montgomery, M.R. James, N.K. Hayward, N.G. Martin, and R.A. Sturm.2004. Interactive effects of MC1R and OCA2 on melanoma risk phenotypes. Human Molecular Genetics 13:447-461. Frost, P.2006. European hair and eye color – A case of frequency-dependent sexual selection? Evolution and Human Behavior 27:85-103 Hughes, K.A., L. Du, F.H. Rodd, and D.N. Reznick.1999. Familiarity leads to female mate preference for novel males in the guppy, Poecilia reticulata, Animal Behaviour 58:907-916. Makova, K, and H. Norton.2005. Worldwide polymorphism at the MC1R locus and normal pigmentation variation in humans. Peptides 26:1901-1908. Sturm, R.A., and T.N. Frudakis.2004. Eye colour: portals into pigmentation genes and ancestry. Trends in Genetics 20:327-332. Thelen, T.H.1983. Minority type human mate preference. Social Biology, 30, 162-180.

What eye color is genetically dominant?

Introduction – Eye colour, or more correctly iris colour, is often used as an example for teaching Mendelian genetics, with brown being dominant and blue being recessive. Colour blindness “Daltonism”, which affects 8% of the male population, is a leading example for teaching X-linked recessive disease (Fig.1 ).

This simple model works well most of the time, with the main blue eye gene OCA2,
We can draw pedigrees showing homozygote blue- and homozygote brown-eyed parents having heterozygote brown-eyed children and then grandchildren who may be homozygote or hererozygote blue- or brown-eyed depending on their other parent (Fig.2 ).

Fig.1: Basic Mendelian Genetics of Eye Colour and Colour Perception. What Race Has Brown Eyes Upper row: Brown, Hazel/Green, Blue and Albino eyes as seen by most of the tritanopic “normal” population. Lower row: the same eyes as would be perceived by a person with X-linked protanopia. Fig.2: Simple four-generation Mendelian Pedigree of Brown and Blue eyes. Phenotype shown as brown or blue while dominant brown gene = B and recessive blue gene = b Individuals with bb have blue eyes, while individuals with BB or Bb have brown eyes. Blue or brown describes only a portion of eye colour. There are intermediate variations of green and hazel, as well as albino eyes, which lack pigment entirely—all examples for which the simple Mendelian model does not apply.

Geneticist Victor McKusick stated, “The early view that blue is a simple recessive has been repeatedly shown to be wrong by observation of brown-eyed offspring of two blue-eyed parents”,
This may have inspired his own interest in genetics, as he and his identical twin brother had brown eyes and their parents had blue! We now know that eye colour is actually a complex genetic trait, involving interaction of some major genes and many minor genes.

What race started blonde hair?

Asia – The higher frequencies of light hair in Asia are prevalent among the Pamiris, Kalash, Nuristani and Uyghur ethnic groups. Even though currently, there is no accepted theory regarding the true origins of blond hair, according to geneticist David Reich, blond hair has ancient roots in Asia.

The derived allele responsible for blond hair in Europeans likely evolved first among the Ancient North Eurasians,
The earliest known individual with this allele is a Siberian fossil from Afontova Gora, in south-central Siberia.
Reich has written that the derived SNP for blond hair entered continental Europe by way of a massive population migration from the Eurasian steppe, by a people who had substantial Ancient North Eurasian ancestry.

Blond hair has been discovered in human burial sites in north-western China and Mongolia dating to the Iron Age. The Hmong people were historically recorded with blonde hair and blue eyes by the Chinese since ancient times. Their light phenotypes made it easy for Chinese to distinguish them.

Chinese historical documents describe blond haired, blue-eyed warriors among the Xiongnu, a nomadic equestrian culture from Mongolia, who practiced Tengriism, The Shiwei people were a Mongolic-speaking ethnic group who were blond-haired and blue eyed. Blond hair can still be seen among people from the region they inhabited, even today.

Some Xianbei were described with blond hair and blue eyes according to Chinese historical chronicles. The Uriankhai tribe of Mongols, to which the military generals Subotai and Jelme belonged, were described by Mongol chronicles as blond haired in the 2nd millennium CE.

What is Caucasian race hair?

Caucasian hair – Caucasian hair can be smooth, wavy or curly. Its colorimetry can vary from blond to dark brown. It grows obliquely, and grows about 1.2 centimeters per month. Caucasian hair has an oval shape. The density of Caucasian hair is the highest of the three ethnic groups, so it is the most dense.

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