Wikipedia

Black hair

This article is about hair that is black in color. For information regarding hair that is the texture of unprocessed African hair, seeAfro-textured hair.

Black hairis the darkest and most common of allhuman hair colorsglobally, due to large populations with this trait. This hair type contains a much more dense quantity ofeumelaninpigmentation in comparison to other hair colors, such as brown, blonde and red.[1]In English, various types of black hair are sometimes described assoft-black,raven black,orjet-black.The range ofskin colorsassociated with black hair is vast, ranging from the palest oflight skintones todark skin.Black-haired humans can have dark or light eyes, but more commonly dark.

Distribution

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Black hair is the most common inAsiaandAfrica.[2]Though this characteristic can also be seen throughoutEuropeas well, it is considerably less common.[3]It can be found inCelticpopulations such as inIreland,ScotlandandWales.[4]Black hair can come in a variety oftextures,just as any hair color. Generally, the East Asian, Central Asian and Native American population hasstraight hairwith a very thickcuticle layer[5]and South Asians have thick, wavy orcurly hair,[6]while the general hair type seen in black African hair is thick, curly and dense with more hair growing from the head. The curly quality comes from the shape of the hair follicle, as straight hair grows from more circular hair follicles, and curly hair grows from more oval-like follicles.[7]

Varieties of black hair

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  • raven black

Naturally, hair reflects light, which is why even black hair does not appear fully dark in the light. However, the darkest shade of black hair, raven-black, does not behave as other hair would in the light. The name of the color comes from a raven’s wing due to similarities in behavior. Appearing as being almost blue in some conditions, this hair color is mostly found with people fromAfrica,SouthandSoutheast Asia,Central AsiaandLatin America.[8]

True black hair is similar to ablack cat's fur.

CleopatrabyJohn William Waterhouse
Ablack catperched on afence.
  • deepest brunette:the darkest brown, which can be a very darkchestnut;sometimes appears to be off-black at a distance, and is often considered to be black.[9]

Genetics

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Native Americans,East Asian,Southeast Asian,Far East Russian,South Asian,Central AsianandHimalayanblack-haired people have thicker hair due to thederived EDAR gene allelethat is linked to thicker and potentially straighter hair in some parts of Asia, andshovel-shaped incisors.The derived EDAR gene arose approximately 30,000 years ago inChina.[10][11][12]One study[which?]shows thatPaleo-Indianshad both variants of the EDAR gene, the derived G-allele and the ancestral A-allele. When they[who?]testedancient DNAremains found in theAmericasof the individuals named USR1,Anzick-1and Laranjal-6700 the results showed that they carried the ancestral A-allele.[citation needed]

11,000-year-old remains of Cuncaicha andLauricochaindividuals fromSouth Americashareallelesat the highest rate with present-dayAmerindians,indicating that the derived G-allele increased infrequencyin parallel with the ancestral A-allele.[13]

One of the most studied genes that producebrown hairisMC1R,which helps the body to produce themelanocortinprotein. This protein in turn helps the body's hair follicles to produce the type of melanin calledeumelanin.To have black hair, one must have genetically inherited this gene from both of their parents, and brown hair is achieved when it is inherited from one parent. This gene is demographically common, as 90% of the total world population carries this gene. Black hair, along with brown hair, comes to turn grey in old age as the hair follicles can no longer produce the pigmentation, but the cause of this inability has yet to be determined.[14]

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See also

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References

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  1. ^"Is hair color determined by genetics?: MedlinePlus Genetics".medlineplus.gov.Retrieved2022-11-17.
  2. ^Goodley, Alvin (2019-10-18)."4 Rarest Hair Colors in the World".Archivedfrom the original on 2020-08-06.
  3. ^The Distribution of Anthropological Traits in Europe,Bertil Lundman:The Races and Peoples of Europe(New York 1977)
  4. ^Hornbeck, Shirley Elro (2000-01-01).This and that Genealogy Tips.Genealogical Publishing Com.ISBN9780806350271.
  5. ^Leerunyakul, Kanchana; Suchonwanit, Poonkiat (April 2020)."Asian Hair: A Review of Structures, Properties, and Distinctive Disorders".Clinical, Cosmetic and Investigational Dermatology.13:309–318.doi:10.2147/CCID.S247390.ISSN1178-7015.PMC7187942.PMID32425573.
  6. ^Mettrie, Roland (October 2007). "Shape Variability and Classification of Human Hair: A Worldwide Approach".Human Biology.79(3):265–281.doi:10.1353/hub.2007.0045.PMID18078200.S2CID39460005.
  7. ^"Why do people of African descent have a unique hair texture?".The Tech Interactive.2021-12-23.Retrieved2022-11-17.
  8. ^"How Many People in The World Have Black Hair?".23 July 2019.
  9. ^McAfee, Clare."Hair Color Chart".wiggoddess.com. Archived fromthe originalon 15 August 2012.Retrieved25 October2012.
  10. ^"Native Americans and Asians carry a version of the EDAR gene that is linked to thicker hair shafts".23 April 2018.
  11. ^Kamberov, Yana G.; Wang, Sijia; Tan, Jingze; Gerbault, Pascale; Wark, Abigail; Tan, Longzhi; Yang, Yajun; Li, Shilin; Tang, Kun; Chen, Hua; Powell, Adam (2013-02-14)."Modeling recent human evolution in mice by expression of a selected EDAR variant".Cell.152(4):691–702.doi:10.1016/j.cell.2013.01.016.ISSN0092-8674.PMC3575602.PMID23415220.
  12. ^Hlusko, Leslea J.; Carlson, Joshua P.; Chaplin, George; Elias, Scott A.; Hoffecker, John F.; Huffman, Michaela; Jablonski, Nina G.; Monson, Tesla A.; O’Rourke, Dennis H.; Pilloud, Marin A.; Scott, G. Richard (2018-05-08)."Environmental selection during the last ice age on the mother-to-infant transmission of vitamin D and fatty acids through breast milk".Proceedings of the National Academy of Sciences of the United States of America.115(19):E4426 –E4432.Bibcode:2018PNAS..115E4426H.doi:10.1073/pnas.1711788115.ISSN0027-8424.PMC5948952.PMID29686092.
  13. ^Posth, C.; et al. (2018)."Reconstructing the Deep Population History of Central and South America".Cell.175(5): 1185–1197.e22.doi:10.1016/j.cell.2018.10.027.PMC6327247.PMID30415837.
  14. ^"Is hair color determined by genetics?: MedlinePlus Genetics".medlineplus.gov.Retrieved2022-11-17.
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