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Wednesday, February 1, 2023

Black people

From Wikipedia, the free encyclopedia

Black is a racialized classification of people, usually a political and skin color-based category for specific populations with a mid to dark brown complexion. Not all people considered "black" have dark skin; in certain countries, often in socially based systems of racial classification in the Western world, the term "black" is used to describe persons who are perceived as dark-skinned compared to other populations. It is most commonly used for people of sub-Saharan African ancestry and the indigenous peoples of Oceania, though it has been applied in many contexts to other groups, and is no indicator of any close ancestral relationship whatsoever. Indigenous African societies do not use the term black as a racial identity outside of influences brought by Western cultures. The term "black" may or may not be capitalized. The AP Stylebook changed its guide to capitalize the "b" in black in 2020. The ASA Style Guide says that the "b" should not be capitalized. Some perceive the term "black" as a derogatory, outdated, reductive or otherwise unrepresentative label, and as a result neither use nor define it, especially in African countries with little to no history of colonial racial segregation.

Contemporary anthropologists and other scientists, while recognizing the reality of biological variation between different human populations, regard the concept of a unified, distinguishable "Black race" as socially constructed. Different societies apply different criteria regarding who is classified "black", and these social constructs have changed over time. In a number of countries, societal variables affect classification as much as skin color, and the social criteria for "blackness" vary. In the United Kingdom, "black" was historically equivalent with "person of color", a general term for non-European peoples. In other regions such as Australasia, settlers applied the term "black" or it was used by local populations with different histories and ancestral backgrounds.

Africa

Northern Africa

The main slave routes in the Middle East and Northern Africa during the Middle Ages.

Numerous communities of dark-skinned peoples are present in North Africa, some dating from prehistoric communities. Others descend from migrants via the historical trans-Saharan trade or, after the Arab invasions of North Africa in the 7th century, from slaves from the trans-Saharan slave trade in North Africa.

Haratin women, a community of recent Sub-Saharan African origin residing in the Maghreb.

In the 18th century, the Moroccan Sultan Moulay Ismail "the Warrior King" (1672–1727) raised a corps of 150,000 black soldiers, called his Black Guard.

According to Carlos Moore, resident scholar at Brazil's University of the State of Bahia, in the 21st century Afro-multiracials in the Arab world, including Arabs in North Africa, self-identify in ways that resemble multi-racials in Latin America. He claims that darker-toned Arabs, much like darker-toned Latin Americans, consider themselves white because they have some distant white ancestry.

Egyptian President Anwar Sadat had a mother who was a dark-skinned Nubian Sudanese (Sudanese Arab) woman and a father who was a lighter-skinned Egyptian. In response to an advertisement for an acting position, as a young man he said, "I am not white but I am not exactly black either. My blackness is tending to reddish".

Due to the patriarchal nature of Arab society, Arab men, including during the slave trade in North Africa, enslaved more African women than men. The female slaves were often put to work in domestic service and agriculture. The men interpreted the Quran to permit sexual relations between a male master and his enslaved females outside of marriage (see Ma malakat aymanukum and sex), leading to many mixed-race children. When an enslaved woman became pregnant with her Arab master's child, she was considered as umm walad or "mother of a child", a status that granted her privileged rights. The child was given rights of inheritance to the father's property, so mixed-race children could share in any wealth of the father. Because the society was patrilineal, the children inherited their fathers' social status at birth and were born free.

Some mixed-race children succeeded their respective fathers as rulers, such as Sultan Ahmad al-Mansur, who ruled Morocco from 1578 to 1608. He was not technically considered as a mixed-race child of a slave; his mother was Fulani and a concubine of his father.

In early 1991, non-Arabs of the Zaghawa people of Sudan attested that they were victims of an intensifying Arab apartheid campaign, segregating Arabs and non-Arabs (specifically, people of Nilotic ancestry). Sudanese Arabs, who controlled the government, were widely referred to as practicing apartheid against Sudan's non-Arab citizens. The government was accused of "deftly manipulat(ing) Arab solidarity" to carry out policies of apartheid and ethnic cleansing.

Sudanese Arabs are also black people in that they are culturally and linguistically Arabized indigenous peoples of Sudan of mostly Nilo-Saharans, Nubian, and Cushitic ancestry; their skin tone and appearance resembles that of other black people.

American University economist George Ayittey accused the Arab government of Sudan of practicing acts of racism against black citizens. According to Ayittey, "In Sudan... the Arabs monopolized power and excluded blacks – Arab apartheid." Many African commentators joined Ayittey in accusing Sudan of practicing Arab apartheid.

Sahara

An Ibenheren (Bella) woman

In the Sahara, the native Tuareg Berber populations kept "negro" slaves. Most of these captives were of Nilotic extraction, and were either purchased by the Tuareg nobles from slave markets in the Western Sudan or taken during raids. Their origin is denoted via the Ahaggar Berber word Ibenheren (sing. Ébenher), which alludes to slaves that only spoke a Nilo-Saharan language. These slaves were also sometimes known by the borrowed Songhay term Bella.

Similarly, the Sahrawi indigenous peoples of the Western Sahara observed a class system consisting of high castes and low castes. Outside of these traditional tribal boundaries were "Negro" slaves, who were drawn from the surrounding areas.

North-Eastern Africa

In Ethiopia and Somalia, the slave classes mainly consisted of captured peoples from the Sudanese-Ethiopian and Kenyan-Somali international borders or other surrounding areas of Nilotic and Bantu peoples who were collectively known as Shanqella and Adone (both analogues to "negro" in an English-speaking context). Some of these slaves were captured during territorial conflicts in the Horn of Africa and then sold off to slave merchants. The earliest representation of this tradition dates from a seventh or eighth century BC inscription belonging to the Kingdom of Damat.

These captives and others of analogous morphology were distinguished as tsalim barya (dark-skinned slave) in contrast with the Afroasiatic-speaking nobles or saba qayh ("red men") or light-skinned slave; while on the other hand, western racial category standards do not differentiate between saba qayh ("red men"—light-skinned) or saba tiqur ("black men"—dark-skinned) Horn Africans (of either Afroasiatic-speaking, Nilotic-speaking or Bantu origin) thus considering all of them as "black people" (and in some case "negro") according to Western society's notion of race.

Southern Africa

In South Africa, the period of colonization resulted in many unions and marriages between European and Africans (Bantu peoples of South Africa and Khoisans) from various tribes, resulting in mixed-race children. As the European colonialists acquired control of territory, they generally pushed the mixed-race and African populations into second-class status. During the first half of the 20th century, the white-dominated government classified the population according to four main racial groups: Black, White, Asian (mostly Indian), and Coloured. The Coloured group included people of mixed Bantu, Khoisan, and European ancestry (with some Malay ancestry, especially in the Western Cape). The Coloured definition occupied an intermediary political position between the Black and White definitions in South Africa. It imposed a system of legal racial segregation, a complex of laws known as apartheid.

The apartheid bureaucracy devised complex (and often arbitrary) criteria in the Population Registration Act of 1945 to determine who belonged in which group. Minor officials administered tests to enforce the classifications. When it was unclear from a person's physical appearance whether the individual should be considered Coloured or Black, the "pencil test" was used. A pencil was inserted into a person's hair to determine if the hair was kinky enough to hold the pencil, rather than having it pass through, as it would with smoother hair. If so, the person was classified as Black. Such classifications sometimes divided families.

Sandra Laing is a South African woman who was classified as Coloured by authorities during the apartheid era, due to her skin colour and hair texture, although her parents could prove at least three generations of European ancestors. At age 10, she was expelled from her all-white school. The officials' decisions based on her anomalous appearance disrupted her family and adult life. She was the subject of the 2008 biographical dramatic film Skin, which won numerous awards. During the apartheid era, those classed as "Coloured" were oppressed and discriminated against. But, they had limited rights and overall had slightly better socioeconomic conditions than those classed as "Black". The government required that Blacks and Coloureds live in areas separate from Whites, creating large townships located away from the cities as areas for Blacks.

In the post-apartheid era, the Constitution of South Africa has declared the country to be a "Non-racial democracy". In an effort to redress past injustices, the ANC government has introduced laws in support of affirmative action policies for Blacks; under these they define "Black" people to include "Africans", "Coloureds" and "Asians". Some affirmative action policies favor "Africans" over "Coloureds" in terms of qualifying for certain benefits. Some South Africans categorized as "African Black" say that "Coloureds" did not suffer as much as they did during apartheid. "Coloured" South Africans are known to discuss their dilemma by saying, "we were not white enough under apartheid, and we are not black enough under the ANC (African National Congress)".

In 2008, the High Court in South Africa ruled that Chinese South Africans who were residents during the apartheid era (and their descendants) are to be reclassified as "Black people," solely for the purposes of accessing affirmative action benefits, because they were also "disadvantaged" by racial discrimination. Chinese people who arrived in the country after the end of apartheid do not qualify for such benefits.

Other than by appearance, "Coloureds" can usually be distinguished from "Blacks" by language. Most speak Afrikaans or English as a first language, as opposed to Bantu languages such as Zulu or Xhosa. They also tend to have more European-sounding names than Bantu names.

Asia

Western Asia

Arab world

Bilal ibn Ribah (pictured atop the Kaaba, Mecca) was a former Ethiopian slave and the first muezzin, ca. 630.

Historians estimate that between the advent of Islam in 650 CE and the abolition of slavery in the Arabian Peninsula in the mid-20th century, 10 to 18 million black Africans (known as the Zanj) were enslaved by east African slave traders and transported to the Arabian Peninsula and neighboring countries. This number far exceeded the number of slaves who were taken to the Americas. Several factors affected the visibility of descendants of this diaspora in 21st-century Arab societies: The traders shipped more female slaves than males, as there was a demand for them to serve as concubines in harems in the Arabian Peninsula and neighboring countries. Male slaves were castrated in order to serve as harem guards. The death toll of black African slaves from forced labor was high. The mixed-race children of female slaves and Arab owners were assimilated into the Arab owners' families under the patrilineal kinship system. As a result, few distinctive Afro-Arab communities have survived in the Arabian Peninsula and neighboring countries.

Distinctive and self-identified black communities have been reported in countries such as Iraq, with a reported 1.2 million black people (Afro-Iraqis), and they attest to a history of discrimination. These descendants of the Zanj have sought minority status from the government, which would reserve some seats in Parliament for representatives of their population. According to Alamin M. Mazrui et al., generally in the Arabian Peninsula and neighboring countries, most of these communities identify as both black and Arab.

Iran

Afro-Iranians are people of black African ancestry residing in Iran. During the Qajar dynasty, many wealthy households imported black African women and children as slaves to perform domestic work. This slave labor was drawn exclusively from the Zanj, who were Bantu-speaking peoples that lived along the African Great Lakes, in an area roughly comprising modern-day Tanzania, Mozambique and Malawi.

Israel

About 150,000 East African and black people live in Israel, amounting to just over 2% of the nation's population. The vast majority of these, some 120,000, are Beta Israel, most of whom are recent immigrants who came during the 1980s and 1990s from Ethiopia. In addition, Israel is home to more than 5,000 members of the African Hebrew Israelites of Jerusalem movement that are ancestry of African Americans who emigrated to Israel in the 20th century, and who reside mainly in a distinct neighborhood in the Negev town of Dimona. Unknown numbers of black converts to Judaism reside in Israel, most of them converts from the United Kingdom, Canada, and the United States.

Additionally, there are around 60,000 non-Jewish African immigrants in Israel, some of whom have sought asylum. Most of the migrants are from communities in Sudan and Eritrea, particularly the Niger-Congo-speaking Nuba groups of the southern Nuba Mountains; some are illegal immigrants.

Turkey

Beginning several centuries ago, during the period of the Ottoman Empire, tens of thousands of Zanj captives were brought by slave traders to plantations and agricultural areas situated between Antalya and Istanbul, which gave rise to the Afro-Turk population in present-day Turkey. Some of their ancestry remained in situ, and many migrated to larger cities and towns. Other black slaves were transported to Crete, from where they or their descendants later reached the İzmir area through the population exchange between Greece and Turkey in 1923, or indirectly from Ayvalık in pursuit of work.

Apart from the historical Afro-Turk presence Turkey also hosts a sizeable immigrant black population since the end of the 1990s. The community is composed mostly of modern immigrants from Ghana, Ethiopia, DRC, Sudan, Nigeria, Kenya, Eritrea, Somalia and Senegal. According to official figures 1.5 million Africans live in Turkey and around 25% of them are located in Istanbul. Other studies state the majority of Africans in Turkey lives in Istanbul and report Tarlabaşı, Dolapdere, Kumkapı, Yenikapı and Kurtuluş as having a strong African presence.

Most of the African immigrants in Turkey come to Turkey to further migrate to Europe. Immigrants from Eastern Africa are usually refugees, meanwhile Western and Central African immigration is reported to be economically driven. It is reported that African immigrants in Turkey regularly face economic and social challenges, notably racism and opposition to immigration by locals.

Southern Asia

A Siddi girl from the town of Yellapur in Uttara Karnataka district, Karnataka, India.

The Siddi are an ethnic group inhabiting India and Pakistan. Members are descended from the Bantu peoples of Southeast Africa. Some were merchants, sailors, indentured servants, slaves or mercenaries. The Siddi population is currently estimated at around 270,000–350,000 individuals, living mostly in Karnataka, Gujarat, and Hyderabad in India and Makran and Karachi in Pakistan. In the Makran strip of the Sindh and Balochistan provinces in southwestern Pakistan, these Bantu descendants are known as the Makrani. There was a brief "Black Power" movement in Sindh in the 1960s and many Siddi are proud of and celebrate their African ancestry.

Southeastern Asia

Ati woman, Philippines – the Negritos are an indigenous people of Southeast Asia.

Negritos, are a collection of various, often unrelated peoples, who were once considered a single distinct population of closely related groups, but genetic studies showed that they descended from the same ancient East Eurasian meta-population which gave rise to modern East Asian peoples, and consist of several separate groups, as well as displaying genetic heterogeneity. They inhabit isolated parts of Southeast Asia, and are now confined primarily to Southern Thailand, the Malay Peninsula, and the Andaman Islands of India.

Population genomic "TreeMix" analysis of Malaysian Negritos (Semang) and closely related populations (eg. East Asians and Andamanese peoples).

Negrito means "little black people" in Spanish (negrito is the Spanish diminutive of negro, i.e., "little black person"); it is what the Spaniards called the aborigines that they encountered in the Philippines. The term Negrito itself has come under criticism in countries like Malaysia, where it is now interchangeable with the more acceptable Semang, although this term actually refers to a specific group.

They have dark skin, often curly-hair and Asiatic facial characteristics, and are stockily built.

Negritos in the Philippines frequently face discrimination. Because of their traditional hunter-gatherer lifestyle, they are marginalized and live in poverty, unable to find employment.

Afro-Asians

"Afro-Asians" or "African-Asians" are persons of mixed sub-Saharan African and Asian ancestry. In the United States, they are also called "black Asians" or "Blasians". Historically, Afro-Asian populations have been marginalized as a result of human migration and social conflict.

Europe

Western Europe

France

Young Negro with a Bow by Hyacinthe Rigaud, ca. 1697.

While census collection of ethnic background is illegal in France, it is estimated that there are about 2.5 – 5 million black people residing there.

Germany

As of 2020, there are approximately one million black people living in Germany.

Netherlands

Afro-Dutch are residents of the Netherlands who are of Black African or Afro-Caribbean ancestry. They tend to be from the former and present Dutch overseas territories of Aruba, Bonaire, Curaçao, Sint Maarten and Suriname. The Netherlands also has sizable Cape Verdean and other African communities.

Spain

The term "Moors" has been used in Europe in a broader, somewhat derogatory sense to refer to Muslims, especially those of Arab or Berber ancestry, whether living in North Africa or Iberia. Moors were not a distinct or self-defined people. Medieval and early modern Europeans applied the name to Muslim Arabs, Berbers, Sub-Saharan Africans and Europeans alike.

Isidore of Seville, writing in the 7th century, claimed that the Latin word Maurus was derived from the Greek mauron, μαύρον, which is the Greek word for "black". Indeed, by the time Isidore of Seville came to write his Etymologies, the word Maurus or "Moor" had become an adjective in Latin, "for the Greeks call black, mauron". "In Isidore's day, Moors were black by definition..."

Afro-Spaniards are Spanish nationals of West/Central African ancestry. Today, they mainly come from Cameroon, Equatorial Guinea, Ghana, Gambia, Mali, Nigeria and Senegal. Additionally, many Afro-Spaniards born in Spain are from the former Spanish colony Equatorial Guinea. Today, there are an estimated 683,000 Afro-Spaniards in Spain.

United Kingdom

According to the Office for National Statistics, at the 2001 census there were more than a million black people in the United Kingdom; 1% of the total population described themselves as "Black Caribbean", 0.8% as "Black African", and 0.2% as "Black other". Britain encouraged the immigration of workers from the Caribbean after World War II; the first symbolic movement was of those who came on the ship the Empire Windrush and, hence, those who migrated between 1948 and 1970 are known as the Windrush generation. The preferred official umbrella term is "black and minority ethnic" (BAME), but sometimes the term "black" is used on its own, to express unified opposition to racism, as in the Southall Black Sisters, which started with a mainly British Asian constituency, and the National Black Police Association, which has a membership of "African, African-Caribbean and Asian origin".

Eastern Europe

Bust of Russian general Abram Gannibal, who was the great-grandfather of Alexander Pushkin.

As African states became independent in the 1960s, the Soviet Union offered many of their citizens the chance to study in Russia. Over a period of 40 years, about 400,000 African students from various countries moved to Russia to pursue higher studies, including many black Africans. This extended beyond the Soviet Union to many countries of the Eastern bloc.

Balkans

Due to the slave trade in the Ottoman Empire that had flourished in the Balkans, the coastal town of Ulcinj in Montenegro had its own black community. In 1878, that community consisted of about 100 people.

Oceania

Indigenous Australians

Unknown Aboriginal woman in 1911

Indigenous Australians have been referred to as "black people" in Australia since the early days of European settlement. While originally related to skin colour, the term is used today to indicate Aboriginal or Torres Strait Islander ancestry in general and can refer to people of any skin pigmentation.

Being identified as either "black" or "white" in Australia during the 19th and early 20th centuries was critical in one's employment and social prospects. Various state-based Aboriginal Protection Boards were established which had virtually complete control over the lives of Indigenous Australians – where they lived, their employment, marriage, education and included the power to separate children from their parents. Aborigines were not allowed to vote and were often confined to reserves and forced into low paid or effectively slave labour. The social position of mixed-race or "half-caste" individuals varied over time. A 1913 report by Baldwin Spencer states that:

the half-castes belong neither to the aboriginal nor to the whites, yet, on the whole, they have more leaning towards the former; ... One thing is certain and that is that the white population as a whole will never mix with half-castes... the best and kindest thing is to place them on reserves along with the natives, train them in the same schools and encourage them to marry amongst themselves.

After the First World War, however, it became apparent that the number of mixed-race people was growing at a faster rate than the white population, and, by 1930, fear of the "half-caste menace" undermining the White Australia ideal from within was being taken as a serious concern. Cecil Cook, the Northern Territory Protector of Natives, noted that:

generally by the fifth and invariably by the sixth generation, all native characteristics of the Australian Aborigine are eradicated. The problem of our half-castes will quickly be eliminated by the complete disappearance of the black race, and the swift submergence of their progeny in the white.

The official policy became one of biological and cultural assimilation: "Eliminate the full-blood and permit the white admixture to half-castes and eventually the race will become white". This led to different treatment for "black" and "half-caste" individuals, with lighter-skinned individuals targeted for removal from their families to be raised as "white" people and prohibited from speaking their native language and practicing traditional customs, a process now known as the Stolen Generation.

Aboriginal activist Sam Watson addressing Invasion Day Rally 2007 in an "Australia has a Black History" T-shirt

The second half of the 20th century to the present has seen a gradual shift towards improved human rights for Aboriginal people. In a 1967 referendum, more than 90% of the Australian population voted to end constitutional discrimination and to include Aborigines in the national census. During this period, many Aboriginal activists began to embrace the term "black" and use their ancestry as a source of pride. Activist Bob Maza said:

I only hope that when I die I can say I'm black and it's beautiful to be black. It is this sense of pride which we are trying to give back to the aborigine [sic] today.

In 1978, Aboriginal writer Kevin Gilbert received the National Book Council award for his book Living Black: Blacks Talk to Kevin Gilbert, a collection of Aboriginal people's stories, and in 1998 was awarded (but refused to accept) the Human Rights Award for Literature for Inside Black Australia, a poetry anthology and exhibition of Aboriginal photography. In contrast to previous definitions based solely on the degree of Aboriginal ancestry, the Government changed the legal definition of Aboriginal in 1990 to include any:

person of Aboriginal or Torres Strait Islander descent who identifies as an Aboriginal or Torres Strait Islander and is accepted as such by the community in which he [or she] lives

This nationwide acceptance and recognition of Aboriginal people led to a significant increase in the number of people self-identifying as Aboriginal or Torres Strait Islander. The reappropriation of the term "black" with a positive and more inclusive meaning has resulted in its widespread use in mainstream Australian culture, including public media outlets, government agencies, and private companies. In 2012, a number of high-profile cases highlighted the legal and community attitude that identifying as Aboriginal or Torres Strait Islander is not dependent on skin color, with a well-known boxer Anthony Mundine being widely criticized for questioning the "blackness" of another boxer and journalist Andrew Bolt being successfully sued for publishing discriminatory comments about Aboriginals with light skin.

Melanesians

The region of Melanesia is named from Greek μέλας, black, and νῆσος, island, etymologically meaning "islands of black [people]", in reference to the dark skin of the indigenous peoples. Early European settlers, such as Spanish explorer Yñigo Ortiz de Retez, noted the resemblance of the people to those in Africa.

Fijian warrior, 1870s.

Melanesians, along with other Pacific Islanders, were frequently deceived or coerced during the 19th and 20th centuries into forced labour for sugarcane, cotton, and coffee planters in countries distant to their native lands in a practice known as blackbirding. In Queensland, some 55,000 to 62,500 were brought from the New Hebrides, the Solomon Islands, and New Guinea to work in sugarcane fields. Under the Pacific Island Labourers Act 1901, most islanders working in Queensland were repatriated back to their homelands. Those who remained in Australia, commonly called South Sea Islanders, often faced discrimination similarly to Indigenous Australians by white-dominated society. Many indigenous rights activists have South Sea Islander ancestry, including Faith Bandler, Evelyn Scott and Bonita Mabo.

Many Melanesians have taken up the term 'Melanesia' as a way to empower themselves as a collective people. Stephanie Lawson writes that the term "moved from a term of denigration to one of affirmation, providing a positive basis for contemporary subregional identity as well as a formal organisation". For instance, the term is used in the Melanesian Spearhead Group, which seeks to promote economic growth among Melanesian countries.

Other

John Caesar, nicknamed "Black Caesar", a convict and bushranger with parents born in an unknown area in Africa, was one of the first people of recent black African ancestry to arrive in Australia.

At the 2006 Census, 248,605 residents declared that they were born in Africa. This figure pertains to all immigrants to Australia who were born in nations in Africa regardless of race, and includes white Africans.

North America

Canada

"Black Canadians" is a designation used for people of black African ancestry who are citizens or permanent residents of Canada. The majority of black Canadians are of Caribbean origin, though the population also consists of African American immigrants and their descendants (including black Nova Scotians), as well as many African immigrants.

Black Canadians often draw a distinction between those of Afro-Caribbean ancestry and those of other African roots. The term African Canadian is occasionally used by some black Canadians who trace their heritage to the first slaves brought by British and French colonists to the North American mainland. Promised freedom by the British during the American Revolutionary War, thousands of Black Loyalists were resettled by the Crown in Canada afterward, such as Thomas Peters. In addition, an estimated ten to thirty thousand fugitive slaves reached freedom in Canada from the Southern United States during the Antebellum years, aided by people along the Underground Railroad.

Many black people of Caribbean origin in Canada reject the term "African Canadian" as an elision of the uniquely Caribbean aspects of their heritage, and instead identify as Caribbean Canadian. Unlike in the United States, where "African American" has become a widely used term, in Canada controversies associated with distinguishing African or Caribbean heritage have resulted in the term "black Canadian" being widely accepted there.

United States

Civil rights activist Martin Luther King Jr.

There were eight principal areas used by Europeans to buy and ship slaves to the Western Hemisphere. The number of enslaved people sold to the New World varied throughout the slave trade. As for the distribution of slaves from regions of activity, certain areas produced far more enslaved people than others. Between 1650 and 1900, 10.24 million enslaved West Africans arrived in the Americas from the following regions in the following proportions:

The main slave routes in the Atlantic Slave Trade.

By the early 1900s, nigger had become a pejorative word in the United States. In its stead, the term colored became the mainstream alternative to negro and its derived terms. After the American Civil Rights Movement, the terms colored and negro gave way to "black". Negro had superseded colored as the most polite word for African Americans at a time when black was considered more offensive. This term was accepted as normal, including by people classified as Negroes, until the later Civil Rights movement in the late 1960s. One well-known example is the use by Dr. Rev. Martin Luther King Jr. of "Negro" in his famous speech of 1963, I Have a Dream. During the American civil rights movement of the 1950s and 1960s, some African-American leaders in the United States, notably Malcolm X, objected to the word Negro because they associated it with the long history of slavery, segregation, and discrimination that treated African Americans as second-class citizens, or worse. Malcolm X preferred Black to Negro, but later gradually abandoned that as well for Afro-American after leaving the Nation of Islam.

Since the late 1960s, various other terms for African Americans have been more widespread in popular usage. Aside from black American, these include Afro-American (in use from the late 1960s to 1990) and African American (used in the United States to refer to Black Americans, people often referred to in the past as American Negroes).

In the first 200 years that black people were in the United States, they primarily identified themselves by their specific ethnic group (closely allied to language) and not by skin color. Individuals identified themselves, for example, as Ashanti, Igbo, Bakongo, or Wolof. However, when the first captives were brought to the Americas, they were often combined with other groups from West Africa, and individual ethnic affiliations were not generally acknowledged by English colonists. In areas of the Upper South, different ethnic groups were brought together. This is significant as the captives came from a vast geographic region: the West African coastline stretching from Senegal to Angola and in some cases from the south-east coast such as Mozambique. A new African-American identity and culture was born that incorporated elements of the various ethnic groups and of European cultural heritage, resulting in fusions such as the Black church and African-American English. This new identity was based on provenance and slave status rather than membership in any one ethnic group.

By contrast, slave records from Louisiana show that the French and Spanish colonists recorded more complete identities of the West Africans, including ethnicities and given tribal names.

The U.S. racial or ethnic classification "black" refers to people with all possible kinds of skin pigmentation, from the darkest through to the very lightest skin colors, including albinos, if they are believed by others to have African ancestry (in any discernible percentage). There are also certain cultural traits associated with being "African American", a term used effectively as a synonym for "black person" within the United States.

In March 1807, Great Britain, which largely controlled the Atlantic, declared the transatlantic slave trade illegal, as did the United States. (The latter prohibition took effect 1 January 1808, the earliest date on which Congress had the power to do so after protecting the slave trade under Article I, Section 9 of the United States Constitution.)

By that time, the majority of black people in the United States were native-born, so the use of the term "African" became problematic. Though initially a source of pride, many blacks feared that the use of African as an identity would be a hindrance to their fight for full citizenship in the United States. They also felt that it would give ammunition to those who were advocating repatriating black people back to Africa. In 1835, black leaders called upon Black Americans to remove the title of "African" from their institutions and replace it with "Negro" or "Colored American". A few institutions chose to keep their historic names, such as the African Methodist Episcopal Church. African Americans popularly used the terms "Negro" or "colored" for themselves until the late 1960s.

The term black was used throughout but not frequently since it carried a certain stigma. In his 1963 "I Have a Dream" speech, Martin Luther King Jr. uses the terms negro fifteen times and black four times. Each time that he uses black, it is in parallel construction with white; for example, "black men and white men".

With the successes of the American Civil Rights Movement, a new term was needed to break from the past and help shed the reminders of legalized discrimination. In place of Negro, activists promoted the use of black as standing for racial pride, militancy, and power. Some of the turning points included the use of the term "Black Power" by Kwame Ture (Stokely Carmichael) and the popular singer James Brown's song "Say It Loud – I'm Black and I'm Proud".

In 1988, the civil rights leader Jesse Jackson urged Americans to use instead the term "African American" because it had a historical cultural base and was a construction similar to terms used by European descendants, such as German American, Italian American, etc. Since then, African American and black have often had parallel status. However, controversy continues over which, if any, of the two terms is more appropriate. Maulana Karenga argues that the term African-American is more appropriate because it accurately articulates their geographical and historical origin. Others have argued that "black" is a better term because "African" suggests foreignness, although black Americans helped found the United States. Still others believe that the term "black" is inaccurate because African Americans have a variety of skin tones. Some surveys suggest that the majority of Black Americans have no preference for "African American" or "black", although they have a slight preference for "black" in personal settings and "African American" in more formal settings.

In the U.S. census race definitions, black and African Americans are citizens and residents of the United States with origins in the black racial groups of Africa. According to the Office of Management and Budget, the grouping includes individuals who self-identify as African American, as well as persons who emigrated from nations in the Caribbean and sub-Saharan Africa. The grouping is thus based on geography, and may contradict or misrepresent an individual's self-identification, since not all immigrants from sub-Saharan Africa are "black". The Census Bureau also notes that these classifications are socio-political constructs and should not be interpreted as scientific or anthropological.

According to U.S. Census Bureau data, African immigrants generally do not self-identify as African American. The overwhelming majority of African immigrants identify instead with their own respective ethnicities (~95%). Immigrants from some Caribbean, Central American and South American nations and their descendants may or may not also self-identify with the term.

Recent surveys of African Americans using a genetic testing service have found varied ancestries that show different tendencies by region and sex of ancestors. These studies found that on average, African Americans have 73.2–80.9% West African, 18–24% European, and 0.8–0.9% Native American genetic heritage, with large variation between individuals.

According to studies in the Journal of Personality and Social Psychology, U.S. residents consistently overestimate the size, physical strength, and formidability of young black men.

One-drop rule

Multiracial social reformer Frederick Douglass.

From the late 19th century, the South used a colloquial term, the one-drop rule, to classify as black a person of any known African ancestry. This practice of hypodescent was not put into law until the early 20th century. Legally, the definition varied from state to state. Racial definition was more flexible in the 18th and 19th centuries before the American Civil War. For instance, President Thomas Jefferson held in slavery persons who were legally white (less than 25% black) according to Virginia law at the time, but, because they were born to slave mothers, they were born into slavery, according to the principle of partus sequitur ventrem, which Virginia adopted into law in 1662.

Outside of the United States, some other countries have adopted the one-drop rule, but the definition of who is black and the extent to which the one-drop "rule" applies varies greatly from country to country.

The one-drop rule may have originated as a means of increasing the number of black slaves and was maintained as an attempt to keep the white race "pure". One of the results of the one-drop rule was the uniting of the African-American community. Some of the most prominent abolitionists and civil-rights activists of the 19th century were multiracial, such as Frederick Douglass, Robert Purvis and James Mercer Langston. They advocated equality for all.

Blackness

Barack Obama—the first person of color, biracial, and self-identified African American President of the United States—was throughout his campaign criticized as being either "too black" or "not black enough".

The concept of blackness in the United States has been described as the degree to which one associates themselves with mainstream African-American culture, politics, and values. To a certain extent, this concept is not so much about race but more about political orientation, culture and behavior. Blackness can be contrasted with "acting white", where black Americans are said to behave with assumed characteristics of stereotypical white Americans with regard to fashion, dialect, taste in music, and possibly, from the perspective of a significant number of black youth, academic achievement.

Due to the often political and cultural contours of blackness in the United States, the notion of blackness can also be extended to non-black people. Toni Morrison once described Bill Clinton as the first black President of the United States, because, as she put it, he displayed "almost every trope of blackness". Clinton welcomed the label.

The question of blackness also arose in the Democrat Barack Obama's 2008 presidential campaign. Commentators questioned whether Obama, who was elected the first president with black ancestry, was "black enough", contending that his background is not typical because his mother was a white American and his father was a black student visitor from Kenya. Obama chose to identify as black and African American.

Mexico

Caribbean

Dominican Republic

The first Afro-Dominican slaves were shipped to the Dominican Republic by Spanish conquistadors during the Transatlantic slave trade.

Puerto Rico

Spanish conquistadors shipped slaves from West Africa to Puerto Rico. Afro-Puerto Ricans in part trace ancestry to this colonization of the island.

South America

Capoeira, an Afro-Brazilian martial art.

Approximately 12 million people were shipped from Africa to the Americas during the Atlantic slave trade from 1492 to 1888. Of these, 11.5 million of those shipped to South America and the Caribbean. Brazil was the largest importer in the Americas, with 5.5 million African slaves imported, followed by the British Caribbean with 2.76 million, the Spanish Caribbean and Spanish Mainland with 1.59 million Africans, and the French Caribbean with 1.32 million. Today their descendants number approximately 150 million in South America and the Caribbean. In addition to skin color, other physical characteristics such as facial features and hair texture are often variously used in classifying peoples as black in South America and the Caribbean. In South America and the Caribbean, classification as black is also closely tied to social status and socioeconomic variables, especially in light of social conceptions of "blanqueamiento" (racial whitening) and related concepts.

Brazil

The concept of race in Brazil is complex. A Brazilian child was never automatically identified with the racial type of one or both of their parents, nor were there only two categories to choose from. Between an individual of unmixed West African ancestry and a very light mulatto individual, more than a dozen racial categories were acknowledged, based on various combinations of hair color, hair texture, eye color, and skin color. These types grade into each other like the colors of the spectrum, and no one category stands significantly isolated from the rest. In Brazil, people are classified by appearance, not heredity.

Scholars disagree over the effects of social status on racial classifications in Brazil. It is generally believed that achieving upward mobility and education results in individuals being classified as a category of lighter skin. The popular claim is that in Brazil, poor whites are considered black and wealthy blacks are considered white. Some scholars disagree, arguing that "whitening" of one's social status may be open to people of mixed race, a large part of the population known as pardo, but a person perceived as preto (black) will continue to be classified as black regardless of wealth or social status.

Statistics

Brazilian Population, by Race, from 1872 to 1991 (Census Data)
Ethnic group White Black Brown Yellow (East Asian) Undeclared Total
1872 3,787,289 1,954,452 4,188,737 9,930,478
1940 26,171,778 6,035,869 8,744,365 242,320 41,983 41,236,315
1991 75,704,927 7,335,136 62,316,064 630,656 534,878 146,521,661
Demographics of Brazil
Year White Pardo Black
1835 24.4% 18.2% 51.4%
2000 53.7% 38.5% 6.2%
2010 48.4% 42.4% 6.7%

From the years 1500 to 1850, an estimated 3.5 million captives were forcibly shipped from West/Central Africa to Brazil. The territory received the highest number of slaves of any country in the Americas. Scholars estimate that more than half of the Brazilian population is at least in part descended from these individuals. Brazil has the largest population of Afro-ancestry outside Africa. In contrast to the US, during the slavery period and after, the Portuguese colonial government in Brazil and the later Brazilian government did not pass formal anti-miscegenation or segregation laws. As in other Latin American countries, intermarriage was prevalent during the colonial period and continued afterward. In addition, people of mixed race (pardo) often tended to marry white spouses, and their descendants became accepted as white. As a result, some of the European descended population also has West African or Amerindian blood. According to the last census of the 20th century, in which Brazilians could choose from five color/ethnic categories with which they identified, 54% of individuals identified as white, 6.2% identified as black, and 39.5% identified as pardo (brown)—a broad multi-racial category, including tri-racial persons.

In the 19th century, a philosophy of racial whitening emerged in Brazil, related to the assimilation of mixed-race people into the white population through intermarriage. Until recently the government did not keep data on race. However, statisticians estimate that in 1835, roughly 50% of the population was preto (black; most were enslaved), a further 20% was pardo (brown), and 25% white, with the remainder Amerindian. Some classified as pardo were tri-racial.

By the 2000 census, demographic changes including the end to slavery, immigration from Europe and Asia, assimilation of multiracial persons, and other factors resulted in a population in which 6.2% of the population identified as black, 40% as pardo, and 55% as white. Essentially most of the black population was absorbed into the multi-racial category by intermixing. A 2007 genetic study found that at least 29% of the middle-class, white Brazilian population had some recent (since 1822 and the end of the colonial period) African ancestry.

Race relations in Brazil

Brazilian Candomblé ceremony

According to the 2010 census, 6.7% of Brazilians said they were black, compared with 6.2% in 2000, and 43.1% said they were racially mixed, up from 38.5%. In 2010, Elio Ferreira de Araujo, Brazil's minister for racial equality, attributed the increases to growing pride among his country's black and indigenous communities.

The philosophy of the racial democracy in Brazil has drawn some criticism, based on economic issues. Brazil has one of the largest gaps in income distribution in the world. The richest 10% of the population earn 28 times the average income of the bottom 40%. The richest 10 percent is almost exclusively white or predominantly European in ancestry. One-third of the population lives under the poverty line, with blacks and other people of color accounting for 70 percent of the poor.

Fruit sellers in Rio de Janeiro c. 1820

In 2015 United States, African Americans, including multiracial people, earned 76.8% as much as white people. By contrast, black and mixed race Brazilians earned on average 58% as much as whites in 2014. The gap in income between blacks and other non-whites is relatively small compared to the large gap between whites and all people of color. Other social factors, such as illiteracy and education levels, show the same patterns of disadvantage for people of color.

Black people in Brazil c. 1821

Some commentators observe that the United States practice of segregation and white supremacy in the South, and discrimination in many areas outside that region, forced many African Americans to unite in the civil rights struggle, whereas the fluid nature of race in Brazil has divided individuals of African ancestry between those with more or less ancestry and helped sustain an image of the country as an example of post-colonial harmony. This has hindered the development of a common identity among black Brazilians.

Though Brazilians of at least partial African heritage make up a large percentage of the population, few blacks have been elected as politicians. The city of Salvador, Bahia, for instance, is 80% people of color, but voters have not elected a mayor of color.

Patterns of discrimination against non-whites have led some academic and other activists to advocate for use of the Portuguese term negro to encompass all African-descended people, in order to stimulate a "black" consciousness and identity.

Colombia

Afro-Colombians are the third-largest African diaspora population in Latin America after Afro-Brazilians and Afro-Haitians.

Venezuela

Most black Venezuelans descend from people brought as slaves to Venezuela directly from Africa during colonization; others have been descendants of immigrants from the Antilles and Colombia. Many blacks were part of the independence movement, and several managed to be heroes. There is a deep-rooted heritage of African culture in Venezuelan culture, as demonstrated in many traditional Venezuelan music and dances, such as the Tambor, a musical genre inherited from black members of the colony, or the Llanera music or the Gaita zuliana that both are a fusion of all the three major peoples that contribute to the cultural heritage. Also, black inheritance is present in the country's gastronomy.

There are entire communities of blacks in the Barlovento zone, as well as part of the Bolívar state and in other small towns; they also live peaceably among the general population in the rest of Venezuela. Currently, blacks represent a plurality of the Venezuelan population, although many are actually mixed people.

Light skin

From Wikipedia, the free encyclopedia
 
A Norwegian woman with light skin

Light skin is a human skin color that has a base level of eumelanin pigmentation that has adapted to environments of low UV radiation. Light skin is most commonly found amongst the native populations of Europe and Northeast Asia as measured through skin reflectance. People with light skin pigmentation are often referred to as "white" or "fair", although these usages can be ambiguous in some countries where they are used to refer specifically to certain ethnic groups or populations.

As populations migrated away from the tropics into areas of low UV radiation, they developed light skin pigmentation as an evolutionary selection acting against vitamin D depletion.

Humans with light skin pigmentation have skin with low amounts of eumelanin, and possess fewer melanosomes than humans with dark skin pigmentation. Light skin provides better absorption qualities of ultraviolet radiation. This helps the body to synthesize higher amounts of vitamin D for bodily processes such as calcium development. Light-skinned people who live near the equator with high sunlight are at an increased risk of folate depletion. As a consequence of folate depletion, they are at a higher risk of DNA damage, birth defects, and numerous types of cancers, especially skin cancer. Humans with darker skin who live further from the tropics have low vitamin D levels, which also can lead to health complications.

The distribution of light-skinned populations is highly correlated with the low ultraviolet radiation levels of the regions inhabited by them. Historically, light-skinned populations almost exclusively lived far from the equator, in high latitude areas with low sunlight intensity. Due to colonization, imperialism, and increased mobility of people between geographical regions in recent centuries, light-skinned populations today are found all over the world.

Evolution

History of human pigmentation in Europe. Scandinavian hunter-gatherers had higher levels of light pigmentation variants compared to their ancestors from other parts of Europe, suggesting adaptation to a low light conditions.

It is generally accepted that dark skin evolved as a protection against the effect of UV radiation; eumelanin protects against both folate depletion and direct damage to DNA. This accounts for the dark skin pigmentation of Homo sapiens during their development in Africa; the major migrations out of Africa to colonize the rest of the world were also dark-skinned. It is widely supposed that light skin pigmentation developed due to the importance of maintaining vitamin D3 production in the skin. Strong selective pressure would be expected for the evolution of light skin in areas of low UV radiation.

Lighter skin tones evolved independently in ancestral populations of north-west and north-east Eurasia, with the two populations diverging around 40,000 years ago. Studies have suggested that the two genes most associated with lighter skin colour in modern Europeans originated in the Middle East and the Caucasus about 22,000 to 28,000 years ago, and were present in Anatolia by 9,000 years ago, where their carriers became associated with the Neolithic Revolution and the spread of Neolithic farming across Europe. Lighter skin and blond hair also evolved in the Ancient North Eurasian population.

A further wave of lighter-skinned populations across Europe (and elsewhere) is associated with the Yamnaya culture and the Indo-European migrations bearing Ancient North Eurasian ancestry and the KITLG allele for blond hair. Furthermore, the SLC24A5 gene linked with light pigmentation in Europeans was introduced into East Africa from Europe over five thousand years ago. These alleles can now be found in the San, Ethiopians, and Tanzanian populations with Afro-Asiatic ancestry. In the San people, it was acquired from interactions with Eastern African pastoralists. Meanwhile, in the case of north-east Asia and the Americas, a variation of the MFSD12 gene is responsible for lighter skin colour. The modern association between skin tone and latitude is thus a relatively recent development.

Geographic distribution; ultraviolet and vitamin D

Tone 2 according to the fitzpatrick scale
 
Skin reflectance vs. latitude
Some people in Mongolia and Manchuria have light skin.

In the 1960s, biochemist W. Farnsworth Loomis suggested that skin colour is related to the body's need for vitamin D. The major positive effect of UV radiation in land-living vertebrates is the ability to synthesize vitamin D3 from it. A certain amount of vitamin D helps the body to absorb more calcium which is essential for building and maintaining bones, especially for developing embryos. Vitamin D production depends on exposure to sunlight. Humans living at latitudes far from the equator developed light skin in order to help absorb more vitamin D. People with light (type II) skin can produce previtamin D3 in their skin at rates 5–10 times faster than dark-skinned (type V) people.

In 1998, anthropologist Nina Jablonski and her husband George Chaplin collected spectrometer data to measure UV radiation levels around the world and compared it to published information on the skin color of indigenous populations of more than 50 countries. The results showed a very high correlation between UV radiation and skin color; the weaker the sunlight was in a geographic region, the lighter the indigenous people's skin tended to be. Jablonski points out that people living above the latitudes of 50 degrees have the highest chance of developing vitamin D deficiency. She suggests that people living far from the equator developed light skin to produce adequate amounts of vitamin D during winter with low levels of UV radiation. Genetic studies suggest that light-skinned humans have been selected for multiple times.

Some people in Afghanistan and Pakistan have light skin.

Polar regions, vitamin D, and diet

A fair-skinned Assyrian woman.

Polar regions of the Northern Hemisphere receive little UV radiation, and even less vitamin D-producing UVB, for most of the year. These regions were uninhabited by humans until about 12,000 years ago. (In northern Fennoscandia at least, human populations arrived soon after deglaciation.) Areas like Scandinavia and Siberia have very low concentrations of ultraviolet radiation, and indigenous populations are all light-skinned.

However, dietary factors may allow vitamin D sufficiency even in dark skinned populations. Many indigenous populations across Eurasia survive by consuming reindeer, which they follow and herd. Reindeer meat, organs, and fat contain large amounts of vitamin D which the reindeer get from eating substantial amounts of lichen. Some people of the polar regions, like the Inuit (Eskimos), retained their dark skin; they ate Vitamin D-rich seafood, such as fish and sea mammal blubber.

Furthermore, these people have been living in the far north for less than 7,000 years. As their founding populations lacked alleles for light skin colour, they may have had insufficient time for significantly lower melanin production to have been selected for by nature. "This was one of the last barriers in the history of human settlement," Jablonski states. "Only after humans learned fishing, and therefore had access to food rich in vitamin D, could they settle regions of high latitude." Additionally, in the spring, Inuit would receive high levels of UV radiation as reflection from the snow, and their relatively darker skin then protects them from the sunlight.

Earlier hypotheses

Two other main hypotheses have been put forward to explain the development of light skin pigmentation: resistance to cold injury, and genetic drift; now both of them are considered unlikely to be the main mechanism behind the evolution of light skin.

The resistance to cold injury hypothesis claimed that dark skin was selected against in cold climates far from the equator and in higher altitudes as dark skin was more affected by frostbite. It has been found that reaction of the skin to extreme cold climates has actually more to do with other aspects, such as the distribution of connective tissue and distribution of fat, and with the responsiveness of peripheral capillaries to differences in temperature, and not with pigmentation.

The supposition that dark skin evolved in the absence of selective pressure was put forward by the probable mutation effect hypothesis. The main factor initiating the development of light skin was seen as a consequence of genetic mutation without an evolutionary selective pressure. The subsequent spread of light skin was thought to be caused by assortive mating and sexual selection contributed to an even lighter pigmentation in females. Doubt has been cast on this hypothesis, as more random patterns of skin coloration would be expected in contrast to the observed structural light skin pigmentation in areas of low UV radiation. The clinal (gradual) distribution of skin pigmentation observable in the Eastern hemisphere, and to a lesser extent in the Western hemisphere, is one of the most significant characteristics of human skin pigmentation. Increasingly lighter skinned populations are distributed across areas with incrementally lower levels of UV radiation.

Genetic associations

Variations in the KITL gene have been positively associated with about 20% of melanin concentration differences between African and non-African populations. One of the alleles of the gene has an 80% occurrence rate in Eurasian populations. The ASIP gene has a 75–80% variation rate among Eurasian populations compared to 20–25% in African populations. Variations in the SLC24A5 gene account for 20–25% of the variation between dark and light skinned populations of Africa, and appear to have arisen as recently as within the last 10,000 years. The Ala111Thr or rs1426654 polymorphism in the coding region of the SLC24A5 gene reaches fixation in Europe, but is found across the globe, particularly among populations in Northern Africa, the Horn of Africa, West Asia, Central Asia and South Asia.

Biochemistry

Melanin is a derivative of the amino acid tyrosine. Eumelanin is the dominant form of melanin found in human skin. Eumelanin protects tissues and DNA from radiation damage by UV light. Melanin is produced in specialized cells called melanocytes, which are found in the lowest level of the epidermis. Melanin is produced inside small membrane-bound packages called melanosomes. Humans with naturally occurring light skin have varied amounts of smaller and sparsely distributed eumelanin and its lighter-coloured relative, pheomelanin. The concentration of pheomelanin varies highly within populations from individual to individual, but it is more commonly found among lightly pigmented Europeans, East Asians, and Native Americans.

For the same body region, individuals, independently of skin colour, have the same amount of melanocytes (however variation between different body parts is substantial), but organelles which contain pigments, called melanosomes, are smaller and less numerous in light-skinned humans.

For people with very light skin, the skin gets most of its colour from the bluish-white connective tissue in the dermis and from the haemoglobin associated blood cells circulating in the capillaries of the dermis. The colour associated with the circulating haemoglobin becomes more obvious, especially in the face, when arterioles dilate and become tumefied with blood as a result of prolonged physical exercise or stimulation of the sympathetic nervous system (usually embarrassment or anger). Up to 50% of UVA can penetrate deeply into the dermis in persons with light skin pigmentation with little protective melanin pigment.

The characteristic of fair skin, red hair, and freckling is associated with high amount of pheomelanin, little amounts of eumelanin. This phenotype is caused by a loss-of-function mutation in the melanocortin 1 receptor (MC1R) gene. However, variations in the MC1R gene sequence only have considerable influence on pigmentation in populations where red hair and extremely fair skin is prevalent. The gene variation's primary effect is to promote eumelanin synthesis at the expense of pheomelanin synthesis, although this contributes to very little variation in skin reflectance between different ethnic groups. Melanocytes from light skin cells cocultured with keratinocytes give rise to a distribution pattern characteristic of light skin.

Freckles usually only occur in people with very lightly pigmented skin. They vary from very dark to brown in colour and develop a random pattern on the skin of the individual. Solar lentigines, the other types of freckles, occur among old people regardless of skin colour. People with very light skin (types I and II) make very little melanin in their melanocytes, and have very little or no ability to produce melanin in the stimulus of UV radiation. This can result in frequent sunburns and a more dangerous, but invisible, damage done to connective tissue and DNA underlying the skin. This can contribute to premature aging and skin cancer. The strongly red appearance of lightly pigmented skin as a response to high UV radiation levels is caused by the increased diameter, number, and blood flow of the capillaries.

People with moderately pigmented skin (Types III-IV) are able to produce melanin in their skin in response to UVR. Normal tanning is usually delayed as it takes time for the melanins to move up in the epidermis. Heavy tanning does not approach the photoprotective effect against UVR-induced DNA damage compared to naturally occurring dark skin, however it offers great protection against seasonal variations in UVR. Gradually developed tan in the spring prevents sunburns in the summer. This mechanism is almost certainly the evolutionary reason behind the development of tanning behaviour.

Health implications

Skin pigmentation is an evolutionary adaptation to the various UV radiation levels around the world. There are health implications of light-skinned people living in environments of high UV radiation. Various cultural practices increase problems related to health conditions of light skin, for example sunbathing among the light-skinned.

Advantages in low sunlight

Humans with light skin pigmentation living in low sunlight environments experience increased vitamin D synthesis compared to humans with dark skin pigmentation due to the ability to absorb more sunlight. Almost every part of the human body, including the skeleton, the immune system, and brain requires vitamin D. Vitamin D production in the skin begins when UV radiation penetrates the skin and interacts with a cholesterol-like molecule produce pre-vitamin D3. This reaction only occurs in the presence of medium length UVR, UVB. Most of the UVB and UVC rays are destroyed or reflected by ozone, oxygen, and dust in the atmosphere. UVB reaches the Earth's surface in the highest amounts when its path is straight and goes through a little layer of atmosphere.

The farther a place is from the equator, the less UVB is received, and the potential to produce of vitamin D is diminished. Some regions far from the equator do not receive UVB radiation at all between autumn and spring. Vitamin D deficiency does not kill its victims quickly, and generally does not kill at all. Rather it weakens the immune system, the bones, and compromises the body's ability to fight uncontrolled cell division which results in cancer. A form of vitamin D is a potent cell growth inhibitor; thus chronic deficiencies of vitamin D seem to be associated with higher risk of certain cancers. This is an active topic of cancer research and is still debated.

With the increase of vitamin D synthesis, there is a decreased incidence of conditions that are related to common vitamin D deficiency conditions of people with dark skin pigmentation living in environments of low UV radiation: rickets, osteoporosis, numerous cancer types (including colon and breast cancer), and immune system malfunctioning. Vitamin D promotes the production of cathelicidin, which helps to defend humans' bodies against fungal, bacterial, and viral infections, including flu. When exposed to UVB, the entire exposed area of body's skin of a relatively light skinned person is able to produce between 10 and 20000 IU of vitamin D.

Disadvantages in high sunlight

Fatal neural tube defect

Light-skinned people living in high sunlight environments are more susceptible to the harmful UV rays of sunlight because of the lack of melanin produced in the skin. The most common risk that comes with high exposure to sunlight is the increased risk of sunburns. This increased risk has come along with the cultural practice of sunbathing, which is popular among light-skinned populations. This cultural practice to gain tanned skin if not regulated properly can lead to sunburn, especially among very lightly-skinned humans. The overexposure to sunlight also can lead to basal cell carcinoma, which is a common form of skin cancer.

Another health implication is the depletion of folate within the body, where the overexposure to UV light can lead to megaloblastic anemia. Folate deficiency in pregnant women can be detrimental to the health of their newborn babies in the form of neural tube defects, miscarriages, and spina bifida, a birth defect in which the backbone and spinal canal do not close before birth. The peak of neural tube defect occurrences is the highest in the May–June period in the Northern Hemisphere. Folate is needed for DNA replication in dividing cells and deficiency can lead to failures of normal embryogenesis and spermatogenesis.

Individuals with lightly pigmented skin who are repeatedly exposed to strong UV radiation, experience faster aging of the skin, which shows in increased wrinkling and anomalies of pigmentation. Oxidative damage causes the degradation of protective tissue in the dermis, which confers the strength of the skin. It has been postulated that white women may develop wrinkles faster after menopause than black women because they are more susceptible to the lifetime damage of the sun throughout life. Dr. Hugh S. Taylor, of Yale School of Medicine, concluded that the study could not prove the findings but they suspect the underlying cause. Light-coloured skin has been suspected to be one of the contributing factors that promote wrinkling.

Dark skin

From Wikipedia, the free encyclopedia
 
A woman with dark skin

Dark skin is a type of human skin color that is rich in melanin pigments. People with very dark skin are often referred to as "black people", although this usage can be ambiguous in some countries where it is also used to specifically refer to different ethnic groups or populations.

The evolution of dark skin is believed to have begun around 1.2 million years ago, in light-skinned early hominid species after they moved from the equatorial rainforest to the sunny savannas. In the heat of the savannas, better cooling mechanisms were required, which were achieved through the loss of body hair and development of more efficient perspiration. The loss of body hair led to the development of dark skin pigmentation, which acted as a mechanism of natural selection against folate (vitamin B9) depletion, and to a lesser extent, DNA damage. The primary factor contributing to the evolution of dark skin pigmentation was the breakdown of folate in reaction to ultraviolet radiation; the relationship between folate breakdown induced by ultraviolet radiation and reduced fitness as a failure of normal embryogenesis and spermatogenesis led to the selection of dark skin pigmentation. By the time modern Homo sapiens evolved, all humans were dark-skinned.

Humans with dark skin pigmentation have skin naturally rich in melanin (especially eumelanin), and have more melanosomes which provide superior protection against the deleterious effects of ultraviolet radiation. This helps the body to retain its folate reserves and protects against damage to DNA.

Dark-skinned people who live in high latitudes with mild sunlight are at an increased risk—especially in the winter—of vitamin D deficiency. As a consequence of vitamin D deficiency, they are at a higher risk of developing rickets, numerous types of cancers, and possibly cardiovascular disease and low immune system activity. However, some recent studies have questioned if the thresholds indicating vitamin D deficiency in light-skinned individuals are relevant for dark-skinned individuals, as they found that, on average, dark-skinned individuals have higher bone density and lower risk of fractures than lighter-skinned individuals with the same levels of vitamin D. This is possibly attributed to lower presence of vitamin D binding agents (and thus its higher bioavailability) in dark-skinned individuals.

The global distribution of generally dark-skinned populations is strongly correlated with the high ultraviolet radiation levels of the regions inhabited by them. These populations, with the exception of indigenous Tasmanians almost exclusively live near the equator, in tropical areas with intense sunlight: Australia, Melanesia, New Guinea, South Asia, Southeast Asia, West Asia, and Africa. Studies into these populations indicates dark skin is not necessarily a retention of the pre-existing high UVR-adapted state of modern humans before the out of Africa migration, but may in fact be a later evolutionary adaptation to tropical rainforest regions. Due to mass migration and increased mobility of people between geographical regions in the recent past, dark-skinned populations today are found all over the world.

Evolution

Due to natural selection, people who lived in areas of intense sunlight developed dark skin colouration to protect against ultraviolet (UV) light, mainly to protect their body from folate depletion. Evolutionary pigmentation of the skin was caused by ultraviolet radiation of the sun. As hominids gradually lost their fur between 1.2 and 4 million years ago, to allow for better cooling through sweating, their naked and lightly-pigmented skin was exposed to sunlight. In the tropics, natural selection favoured dark-skinned human populations as high levels of skin pigmentation protected against the harmful effects of sunlight. Indigenous populations' skin reflectance (the amount of sunlight the skin reflects) and the actual UV radiation in a particular geographic area is highly correlated, which supports this idea. Genetic evidence also supports this notion, demonstrating that around 1.2 million years ago there was a strong evolutionary pressure which acted on the development of dark skin pigmentation in early members of the genus Homo. The effect of sunlight on folic acid levels has been crucial in the development of dark skin.

Savannas in East Africa, where most of the hominid evolution of dark skin may have taken place

The earliest primate ancestors of modern humans most likely had light skin, like our closest modern relative—the chimpanzee. About 7 million years ago human and chimpanzee lineages diverged, and between 4.5 and 2 million years ago early humans moved out of rainforests to the savannas of East Africa. They not only had to cope with more intense sunlight but had to develop a better cooling system. It was harder to get food in the hot savannas and as mammalian brains are prone to overheating—5 or 6 °C rise in temperature can lead to heatstroke—there was a need for the development of better heat regulation. The solution was sweating and loss of body hair.

Sweating dissipated heat through evaporation. Early humans, like chimpanzees now, had few sweat glands, and most of them were located in the palms of the hand and the soles of the feet. At times, individuals with more sweat glands were born. These humans could search for food and hunt for longer periods before being forced back to the shades. The more they could forage, the more and healthier offspring they could produce, and the higher the chance they had to pass on their genes for abundant sweat glands. With less hair, sweat could evaporate more easily and cool the bodies of humans faster. A few million years of evolution later, early humans had sparse body hair and more than 2 million sweat glands in their body.

Hairless skin, however, is particularly vulnerable to be damaged by ultraviolet light and this proved to be a problem for humans living in areas of intense UV radiation, and the evolutionary result was the development of dark-coloured skin as a protection. Scientists have long assumed that humans evolved melanin in order to absorb or scatter harmful sun radiation. Some researchers assumed that melanin protects against skin cancer. While high UV radiation can cause skin cancer, the development of cancer usually occurs after child-bearing age. As natural selection favours individuals with traits of reproductive success, skin cancer had little effect on the evolution of dark skin. Previous hypotheses suggested that sunburned nipples impeded breastfeeding, but a slight tan is enough to protect mothers against this issue.

A 1978 study examined the effect of sunlight on folate—a vitamin B complex—levels. The study found that even short periods of intense sunlight are able to halve folate levels if someone has light skin. Low folate levels are correlated with neural tube defects, such as anencephaly and spina bifida. UV rays can strip away folate, which is important to the development of healthy foetuses. In these abnormalities children are born with an incomplete brain or spinal cord. Nina Jablonski, a professor of anthropology and expert on evolution of human skin coloration, found several cases in which mothers' visits to tanning studios were connected to neural tube defects in early pregnancy. She also found that folate was crucial to sperm development; some male contraception drugs are based on folate inhibition. It has been found that folate may have been the driving force behind the evolution of dark skin.

As humans dispersed from equatorial Africa to low UVR areas and higher latitudes sometime between 120,000 and 65,000 years ago, dark skin posed a disadvantage. Populations with light skin pigmentation evolved in climates of little sunlight. Light skin pigmentation protects against vitamin D deficiency. It is known that dark-skinned people who have moved to climates of limited sunlight can develop vitamin D-related conditions such as rickets, and different forms of cancer.

A 2022 study revealed that traits such as dark skin show strong signals for Convergent evolution and selective pressure (positive Selection).

Other hypotheses

The main other hypotheses that have been put forward through history to explain the evolution of dark skin coloration relate to increased mortality due to skin cancers, enhanced fitness as a result of protection against sunburns, and increasing benefits due to antibacterial properties of eumelanin.

Darkly pigmented, eumelanin-rich skin protects against DNA damage caused by the sunlight. This is associated with lower skin cancer rates among dark-skinned populations. The presence of pheomelanin in light skin increases the oxidative stress in melanocytes, and this combined with the limited ability of pheomelanin to absorb UVR contributes to higher skin cancer rates among light-skinned individuals. The damaging effect of UVR on DNA structure and the entailing elevated skin cancer risk is widely recognized. However, these cancer types usually affect people at the end or after their reproductive career and could have not been the evolutionary reason behind the development of dark skin pigmentation. Of all the major skin cancer types, only malignant melanoma have a major effect in a person's reproductive age. The mortality rates of melanoma have been very low (less than 5 per 100,000) before the mid-20th century. It has been argued that the low melanoma mortality rates during reproductive age cannot be the principal reason behind the development of dark skin pigmentation.

Studies have found that even serious sunburns could not affect sweat gland function and thermoregulation. There are no data or studies that support that sunburn can cause damage so seriously it can affect reproductive success.

Another group of hypotheses contended that dark skin pigmentation developed as antibacterial protection against tropical infectious diseases and parasites. Although it is true that eumelanin has antibacterial properties, its importance is secondary to 'physical adsorption' (physisorption) to protect against UVR-induced damage. This hypothesis is not consistent with the evidence that most of the hominid evolution took place in savanna environments and not in tropical rainforests. Humans living in hot and sunny environments have darker skin than humans who live in wet and cloudy environments. The antimicrobial hypothesis also does not explain why some populations (like the Inuit or Tibetans) who live far from the tropics and are exposed to high UVR have darker skin pigmentation than their surrounding populations.

Biochemistry and genetics

Darkly pigmented skin

Dark-skinned humans have high amounts of melanin found in their skin. Melanin is derivative of the amino acid tyrosine. Eumelanin is the dominant form of melanin found in human skin. Eumelanin protects tissues and DNA from the radiation damage of UV light. Melanin is produced in specialized cells called melanocytes, which are found at the lowest level of the epidermis. Melanin is produced inside small membrane-bound packages called melanosomes. People with naturally-occurring dark skin have melanosomes which are clumped, large and full of eumelanin. A four-fold difference in naturally-occurring dark skin gives seven- to eight-fold protection against DNA damage, but even the darkest skin colour cannot protect against all damage to DNA.

Dark skin offers great protection against UVR because of its eumelanin content, the UVR-absorbing capabilities of large melanosomes, and because eumelanin can be mobilized faster and brought to the surface of the skin from the depths of the epidermis. For the same body region, light- and dark-skinned individuals have similar numbers of melanocytes (there is considerable variation between different body regions), but pigment-containing organelles, called melanosomes, are larger and more numerous in dark-skinned individuals. Keratocytes from dark skin cocultured with melanocytes give rise to a melanosome distribution pattern characteristic of dark skin. Melanosomes are not in aggregated state in darkly pigmented skin compared to lightly pigmented skin. Due to the heavily melanised melanosomes in darkly-pigmented skin, it can absorb more energy from UVR and thus offers better protection against sunburns and by absorption and dispersion UV rays.

Darkly-pigmented skin protects against direct and indirect DNA damage. Photodegration occurs when melanin absorbs photons. Recent research suggest that the photoprotective effect of dark skin is increased by the fact that melanin can capture free radicals, such as hydrogen peroxide, which are created by the interaction of UVR and layers of the skin. Heavily pigmented melanocytes have greater capacity to divide after ultraviolet irradiation, which suggests that they receive less damage to their DNA. Despite this, medium-wave ultraviolet radiation (UVB) damages the immune system even in darker skinned individuals due to its effect on Langerhans cells. The stratum corneum of people with dark or heavily tanned skin is more condensed and contains more cornified cell layers than in lightly-pigmented humans. These qualities of dark skin enhance the barrier protection function of the skin.

Although darkly-pigmented skin absorbs about 30 to 40% more sunlight than lightly-pigmented skin, dark skin does not increase the body's internal heat intake in conditions of intense solar radiation. Solar radiation heats up the body's surface and not the interior. Furthermore, this amount of heat is negligible compared to the heat produced when muscles are actively used during exercise. Regardless of skin colour, humans have excellent capabilities to dissipate heat through sweating. Half of the solar radiation reaching the Earth's surface is in the form of infrared light and is absorbed similarly regardless of skin coloration.

In people with naturally occurring dark skin, the tanning occurs with the dramatic mobilization of melanin upward in the epidermis and continues with the increased production of melanin. This accounts for the fact that dark-skinned people get visibly darker after one or two weeks of sun exposure, and then lose their colour after months when they stay out of the sun. Darkly-pigmented people tend to exhibit fewer signs of aging in their skin than the lightly-pigmented because their dark skin protects them from most photoaging.

Skin colour is a polygenic trait, which means that several different genes are involved in determining a specific phenotype. Many genes work together in complex, additive, and non-additive combinations to determine the skin colour of an individual. The skin colour variations are normally distributed from light to dark, as it is usual for polygenic traits.

Data collected from studies on MC1R gene has shown that there is a lack of diversity in dark-skinned African samples in the allele of the gene compared to non-African populations. This is remarkable given that the number of polymorphisms for almost all genes in the human gene pool is greater in African samples than in any other geographic region. So, while the MC1Rf gene does not significantly contribute to variation in skin colour around the world, the allele found in high levels in African populations probably protects against UV radiation and was probably important in the evolution of dark skin.

Skin colour seems to vary mostly due to variations in a number of genes of large effect as well as several other genes of small effect (TYR, TYRP1, OCA2, SLC45A2, SLC24A5, MC1R, KITLG and SLC24A4). This does not take into account the effects of epistasis, which would probably increase the number of related genes. Variations in the SLC24A5 gene account for 20–25% of the variation between dark- and light-skinned populations of Africa, and appear to have arisen as recently as within the last 10,000 years. The Ala111Thr or rs1426654 polymorphism in the coding region of the SLC24A5 gene reaches fixation in Europe, and is also common among populations in North Africa, the Horn of Africa, West Asia, Central Asia and South Asia.

Health implications

Skin pigmentation is an evolutionary adaptation to various UVR levels around the world. As a consequence there are many health implications that are the product of population movements of humans of certain skin pigmentation to new environments with different levels of UVR. Modern humans are often ignorant of their evolutionary history at their peril. Cultural practices that increase problems of conditions among dark-skinned populations are traditional clothing and vitamin D-poor diet.

Advantages in high sunlight

Dark-pigmented people living in high sunlight environments are at an advantage due to the high amounts of melanin produced in their skin. The dark pigmentation protects from DNA damage and absorbs the right amounts of UV radiation needed by the body, as well as protects against folate depletion. Folate is a water-soluble vitamin B complex which naturally occurs in green, leafy vegetables, whole grains, and citrus fruits. Women need folate to maintain healthy eggs, for proper implantation of eggs, and for the normal development of placenta after fertilization. Folate is needed for normal sperm production in men. Furthermore, folate is essential for fetal growth, organ development, and neural tube development. Folate breaks down in high intensity UVR. Dark-skinned women suffer the lowest level of neural tube defects. Folate plays an important role in DNA production and gene expression. It is essential for maintaining proper levels of amino acids which make up proteins. Folate is used in the formation of myelin, the sheath that covers nerve cells and makes it possible to send electrical signals quickly. Folate also plays an important role in the development of many neurotransmitters, e.g. serotonin which regulates appetite, sleep, and mood. Serum folate is broken down by UV radiation or alcohol consumption. Because the skin is protected by the melanin, dark-pigmented people have a lower chance of developing skin cancer and conditions related to folate deficiency, such as neural tube defects.

Disadvantages in low sunlight

Rickets is a condition associated with dark skin.

Dark-skinned people living in low sunlight environments have been recorded to be very susceptible to vitamin D deficiency due to reduced vitamin D synthesis. A dark-skinned person requires about six times as much UVB than lightly-pigmented persons. This is not a problem near the equator; however, it can be a problem at higher latitudes. For humans with dark skin in climates of low UVR, it can take about two hours to produce the same amount of vitamin D as humans with light skin produce in 15 minutes. Dark-skinned people having a high body-mass index and not taking vitamin D supplements were associated with vitamin D deficiency. Vitamin D plays an important role in regulating the human immune system and chronic deficiencies in vitamin D can make humans susceptible to specific types of cancers and many kinds of infectious diseases. Vitamin D deficiency increases the risk of developing tuberculosis five-fold and also contributes to the development of breast, prostate, and colorectal cancer.

The most prevalent disease to follow vitamin D deficiency is rickets, the softening of bones in children potentially leading to fractures and deformity. Rickets is caused by reduced vitamin D synthesis that causes an absence of vitamin D, which then causes the dietary calcium to not be properly absorbed. This disease in the past was commonly found among dark-skinned Americans of the southern part of the United States who migrated north into low sunlight environments. The popularity of sugary drinks and decreased time spent outside have contributed to significant rise of developing rickets. Deformities of the female pelvis related to severe rickets impair normal childbirth, which leads to higher mortality of the infant, mother, or both.

Vitamin D deficiency is most common in regions with low sunlight, especially in the winter. Chronic deficiencies in vitamin D may also be linked with breast, prostate, colon, ovarian, and possibly other types of cancers. The relationship between cardiovascular disease and vitamin D deficiency also suggest a link between health of cardiac and smooth muscle. Low vitamin D levels have also been linked to impaired immune system and brain functions. In addition, recent studies have linked vitamin D deficiency to autoimmune diseases, hypertension, multiple sclerosis, diabetes and incidence of memory loss.

Outside the tropics UVR has to penetrate through a thicker layer of atmosphere, which results in most of the intermediate wavelength UVB reflected or destroyed en route; because of this there is less potential for vitamin D biosynthesis in regions far from the equator. Higher amount of vitamin D intake for dark-skinned people living in regions with low levels of sunlight are advised by doctors to follow a vitamin D-rich diet or take vitamin D supplements, although there is recent evidence that dark-skinned individuals are able to process vitamin D more efficiently than lighter-skinned individuals so may have a lower threshold of sufficiency.

Geographic distribution

There is a correlation between the geographic distribution of UV radiation (UVR) and the distribution of skin pigmentation around the world. Areas that have higher amounts of UVR have darker-skinned populations, generally located nearer the equator. Areas that are further away from the equator and generally closer to the poles have a lower concentration of UVR and contain lighter-skinned populations. This is the result of human evolution which contributed to variable melanin content in the skin to adapt to certain environments. A larger percentage of dark-skinned people are found in the Southern Hemisphere because latitudinal land mass distribution is disproportionate. The present distribution of skin colour variation does not completely reflect the correlation of intense UVR and dark skin pigmentation due to mass migration and movement of peoples across continents in the recent past. Dark-skinned populations inhabiting Africa, Australia, Melanesia, Papua New Guinea and South Asia all live in some of the areas with the highest UV radiation in the world, and have evolved very dark skin pigmentations as protection from the sun's harmful rays. Evolution has restricted humans with darker skin in tropical latitudes, especially in non-forested regions, where ultraviolet radiation from the sun is usually the most intense. Different dark-skinned populations are not necessarily closely related genetically. Before the modern mass migration, it has been argued that the majority of dark-pigmented people lived within 20° of the equator.

Natives of Buka and Bougainville at the northern Solomon Islands in Melanesia and the Chopi people of Mozambique in the southeast coast of Africa have darker skin than other surrounding populations. (The native people of Bougainville, Papua New Guinea, have some of the darkest skin pigmentation in the world.) Although these people are widely separated they share similar physical environments. In both regions, they experience very high UVR exposure from cloudless skies near the equator which is reflected from water or sand. Water reflects, depending on colour, about 10 to 30% of UVR that falls on it. People in these populations spend long hours fishing on the sea. Because it is impractical to wear extensive clothing in a watery environment, culture and technology does little to buffer UVR exposure. The skin takes a very large amount of ultraviolet radiation. These populations are probably near or at the maximum darkness that human skin can achieve.

More recent research has found that human populations over the past 50,000 years have changed from dark-skinned to light-skinned and vice versa. Only 100–200 generations ago, the ancestors of most people living today likely also resided in a different place and had a different skin color. According to Nina Jablonski, darkly-pigmented modern populations in South India and Sri Lanka are an example of this, having re-darkened after their ancestors migrated down from areas much farther north. Scientists originally believed that such shifts in pigmentation occurred relatively slowly. However, researchers have since observed that changes in skin coloration can happen in as little as 100 generations (~2,500 years), with no intermarriage required. The speed of change is also affected by clothing, which tends to slow it down.

Australia

An Aboriginal Australian man with dark skin

The Aborigines of Australia, as with all humans, are descendants of the Out-of-Africa wave, and their ancestors may have been among the first major groups to leave Africa around 50,000 years ago. Despite early migrations, genetic evidence has pointed out that the indigenous peoples of Australia are genetically very dissimilar to the dark-skinned populations of Africa and that they are more closely related to Eurasian populations.

The term black initially has been applied as a reference to the skin pigmentation of the aborigines of Australia; today it has been embraced by aboriginal activists as a term for shared culture and identity, regardless of skin colour.

Melanesia

Dark-skinned blond boy from Vanuatu, Melanesia

Melanesia, a subregion of Oceania, whose name means "black islands", have several islands that are inhabited by people with dark skin pigmentation. The islands of Melanesia are located immediately north and northeast of Australia as well as east coast of Papua New Guinea. The western end of Melanesia from New Guinea through the Solomon Islands were first colonized by humans about 40,000 to 29,000 years ago.

In the world, blond hair is exceptionally rare outside Europe and West Asia, especially among dark-skinned populations. However, Melanesians are one of the dark-skinned human populations known to have naturally-occurring blond hair.

New Guinea

Buka boys from Bougainville Island, Papua New Guinea. People from Bougainville have some of the darkest skin tones among humans.

The indigenous Papuan people of New Guinea have dark skin pigmentation and have inhabited the island for at least 40,000 years. Due to their similar phenotype and the location of New Guinea being in the migration route taken by Indigenous Australians, it was generally believed that Papuans and Aboriginal Australians shared a common origin. However, a 1999 study failed to find clear indications of a single shared genetic origin between the two populations, suggesting multiple waves of migration into Sahul with distinct ancestries.

Sub-Saharan Africa

Women from South Sudan

Sub-Saharan Africa is the region in Africa situated south of the Sahara where a large number of dark-skinned populations live. Dark-skinned groups on the continent have the same receptor protein as Homo ergaster and Homo erectus had. According to scientific studies, populations in Africa also have the highest skin color diversity. High levels of skin color variation exists between different populations in Sub-Saharan Africa. These differences depend in part on general distance from the equator, illustrating the complex interactions of evolutionary forces which have contributed to the geographic distribution of skin color at any point of time.

Due to frequently differing ancestry among dark-skinned populations, the presence of dark skin in general is not a reliable genetic marker, including among groups in Africa. For example, Wilson et al. (2001) found that most of their Ethiopian samples showed closer genetic affinities with lighter-skinned Armenians than with darker-skinned Bantu populations. Mohamoud (2006) likewise observed that their Somali samples were genetically more similar to Arab populations than to other African populations.

South Asia

Fisherman from Chennai, Tamil Nadu in southern India.

South Asia has some of the greatest skin color diversity outside of Africa. Skin color among South Indians is on average darker than North Indians. This is mainly because of the weather conditions in South Asia—higher UV indices are in the south. Several genetic surveys of South Asian populations in different regions have found a weak negative correlation between social status and skin darkness, represented by the melanin index. A study of caste populations in the Gangetic Plain found an association between the proportion of dark skin and ranking in the caste hierarchy. Dalits had, on average, the darkest skin. A pan-India study of Telugu and North Indian castes found a similar correlation between skin color and caste association, linked to the absence of the rs1426654-A variant of the SLC245-A gene, but are also linked to mutations overriding these variants.

Americas

A dark-skinned Wayuu couple from Colombia. Many other Indigenous peoples of tropical or subtropical areas of the Americas have dark skin.

Relatively dark skin remains among the Inuit and other Arctic populations. A combination of protein-heavy diets and summer snow reflection have been speculated as favouring the retention of pigmented skin.

Earliest European colonial descriptions of North American populations include terms such as "brown", "tawny" or "olive", though some populations were also described as "light-skinned". Most North American indigenous populations rank similar to African and Oceanian populations in regards to the presence of the allele Ala111.

Native South Americans and Mesoamericans are also typically considered dark-skinned. High ultraviolet radiation levels occur throughout the Andes region of Peru, Bolivia, Chile, and Argentina.

Culture

The preference or disfavour for darker skin has varied depending on geographical area and time. Today, darker skin is viewed as fashionable and as a sign of well-being in some societies. This resulted in the development of tanning industry in several countries. However, in some countries, dark skin is not seen as highly desirable or indicative of higher class, especially among women.

Inequality (mathematics)

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