When did White become White?

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When did White become White?

http://www.buildinghistory.org/distantpast/looks.shtml





Whereas most of the peoples of the planet have uniformly black hair and dark eyes, people with origins in Europe, Western Asia and North Africa have a wider range of colouring. Why is that? Dark skin protects people from ultra-violet light, but for that very reason makes it more difficult for their skin to synthesize vitamin D, essential for bone growth and activation of the immune system. Pale people in sunny places are at higher risk of skin cancer and folate deficiency, while dark people in cooler climes are prone to problems of low vitamin D. So it has long been supposed that the range of skin colours we see today arose through natural selection - M.Jobling, M.E. Hules and C. Tyler-Smith, Human Evolutionary Genetics (2004), Section 13.3 and Box 13.4 provide an introduction to the subject, updated by A. Juzeniene et al., Development of different human skin colors: A review highlighting photobiological and photobiophysical aspects, Journal of Photochemistry and Photobiology B: Biology, vol. 96, no. 2 (3 August 2009), pp. 93-100; M. Rode von Essen et al, Vitamin D controls T cell antigen receptor signaling and activation of human T cells, Nature Immunology (print 7 March 2010).

There are at least 11 genes involved in skin pigmentation. So far it looks as though one biological path to paler skin does not interfere with the ancestral dark hair and eyes, while another throws up red hair as a side effect, with another you get blond hair, and mixtures give in between shades - F. Liu et al., Digital quantification of human eye color highlights genetic association of three new loci, PLoS Genetics, vol. 6, no. 5 (2010), e1000934; J. Mengel-From et al., Genetic determinants of hair and eye colour in the Scottish and Danish populations, BMC Genetics vol. 10 (December 2009) 88; R.A. Sturm, Molecular genetics of human pigmentation diversity, Human Molecular Genetics, vol. 15, no. 18(R1) (April 2009), R9-17; W. Branicki, Interactions between HERC2, OCA2 and MC1R may influence human pigmentation phenotype, Annals Human Genetics, vol. 73, no. 2 (Mar 2009), pp.160-70.

Scientists calculate that the new allele causing paler skin cropped up on gene SLC24A5 only around 5300 to 6000 years ago. It is nicknamed the golden gene, as it also causes golden stripes in zebrafish - R.L. Lamason et al, SLC24A5 affects pigmentation in zebrafish and man, Science vol. 310 (2005), pp.1782-1786; A. Gibbons, European skin turned pale only recently, gene suggests, Science, vol. 316, no. 5823 (20 April 2007), p.364. While the golden gene and two others (SLC45A2 and KITLG) cause most of the paleness of Europeans and their relatives, East Asians have their own colour-drainer (His615Arg in OCA2), as well as KITLG, showing independent evolution after their ancestors moved deeper into Asia.

However the similar distribution of alleles in the KITLG gene within Western Eurasians and East Asians suggests that some selection for paler skin is older - M. Edwards et al., Association of the OCA2 polymorphism His615Arg with melanin content in East Asian populations: further evidence of convergent evolution of skin pigmentation, PLoS Genetics, vol. 6, no.3 (March 2010); H.L. Norton, Genetic evidence for the convergent evolution of light skin in Europeans and East Asians, Molecular Biology and Evolution, vol. 24 (2007), pp.710-722.

Early (non-white?) Europeans boosted their vitamin D intake by eating fatty fish and fish eggs. Salmon bones, fish hooks, and paintings of salmon, trout, and pike have been found in caves they occupied - G.E. Adán et al., Fish as diet resource in North Spain during the Upper Paleolithic, Journal of Archaeological Science, vol. 36, no. 3 (March 2009), pp. 895-899. The range of the most recent mutations for lighter colouring suggests that they were first spread by the early farmers from the Near East: Europe, Western Asia and North Africa. For example SLC24A5 is found in 60-70% of the population in Tunisia and Morocco - G. Lucotte et al., A Decreasing Gradient of 374F Allele Frequencies in the Skin Pigmentation Gene SLC45A2, from the North of West Europe to North Africa, Biochemical Genetics, vol. 48, nos. 1-2 (2010), pp. 26-33.

The present range of hair colouring is documented around 3000 BC in rock paintings from the Tassili n’Ajjer plateau, Algeria - S. di Lernia and M. Gallinaro, The date and context of Neolithic rock art in the Sahara: engravings and ceremonial monuments from Messak Settafet (south-west Libya), Antiquity, vol. 84, no. 326 (December 2010), pp. 954–975.

Worshippers at Sumerian temples could be depicted with either blue or brown eyes. The same is true of ancient Egyptians of the same period. There is no reason to think that blue eyes predominated in these populations, but every reason to accept that they existed.

The predominant gene for blue eyes (rs12913832 GG) appeared between 6,000 and 10,000 years ago. Professor Hans Eiberg and his team analysed the DNA of people with blue eyes in Denmark, Turkey and Jordan. All of them had exactly the same DNA sequence covering half the HERC2 gene. That suggests a common ancestor. Eiberg and his colleages surmised the mutations responsible for the blue eye color most likely originate from the Near East area or northwest part of the Black Sea region, where the great agriculture migration to the northern part of Europe took place in the Neolithic periods about 6–10,000 years ago - H. Eiberg et al, Blue eye color in humans may be caused by a perfectly associated founder mutation in a regulatory element located within the HERC2 gene inhibiting OCA2 expression, Human Genetics, vol.123, no 2 (Mar 2008), pp. 177-87.

What would be the advantage of blue eyes in northern climes? The lower melanin in blue eyes makes it easier to absorb light in winter and so protect against Seasonal Affective Disorder (SAD) - S. Higuchi et al., Influence of eye colors of Caucasians and Asians on suppression of melatonin secretion by light, American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, vol. 292, no. 6 (June 2007), pp. R2352-R2356.

There are two types of melanin. Black and brown pigments are formed from eumelanin. Red and yellow result from pheomelanin. Mutations on the MC1R gene, causing loss of only eumelanin, result in yellow or red coat colours in many mammals. Man is no different. Some of these mutations appear in redheads - Helgi B. Schiöth et al., Loss of function mutations of the human melanocortin 1 receptor are common and are associated with red hair, Biochemical and Biophysical Research Communications, vol. 260, no. 2, (5 July 1999), pp. 488-491.

Red hair is not restricted to Celts. It is not even restricted to Indo-Euopeans. In the 4th century BC Herodotus described a nomadic, foraging tribe called the Budini with piercing grey eyes and bright red hair, who lived in the forest east of the River Don and 15 days journey north of the Sea of Azov - Herodotus, The Histories, 4.21-2, 108-9. They sound like the Udmurts, who claim as many red-heads as the Irish. The Udmurt Republic lies in Russia, in the forest zone between two tributaries of the Volga. The Udmurts speak a Finno-Ugric language. They now celebrate their rufosity each September with the Red Festival.

At Hierakonpolis 43 (c.3600-3400BC), most of the hair found on mummies is very dark brown, showing that this colour can be preserved for millennia, and that it was the most common. Yet male burial no. 79 had natural wavy, red hair - J. Fletcher, The Secrets of the Locks Unraveled. Nekhen News, Vol 10, (Milwaukee Public Museum 1998), pp. 7-8.

Red hair was evidently rare in Ancient Egypt, as it is in North Africa today. But it crops up occasionally among the Berbers of Algeria and Morocco.

P.S. – In my view, the only reason that “agriculturalists” would have been successful enough to spread in the first place is that they combined grain and vegetable farming with herding; otherwise, they would have been little better off than neighboring seed gatherers and bird/small mammal trappers.

If they were also adult lactose-tolerant, the value of keeping a herd would have been maximized; they would have had both a considerable nutritional advantage AND developed a sense of movable property, leading to a completely new and different civilization.

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