The Melanin Dosage Test by Cheikh Anta Diop

Below is an extract from an article originally published in French under the title “Pigmentation des anciens Égyptiens. Test par la mélanine” by CHEIKH ANTA DIOP. We transcribed it and translated it into English. The original source material can be found on Abibitumi Kasa.

BULLETIN

OF

THE FUNDAMENTAL INSTITUTE OF BLACK AFRICA

SERIES B, HUMAN SCIENCES

Volume XXXV No. 3 July 1973

Pigmentation of the ancient Egyptians.

Melanin test

By CHEIKH ANTA DIOP.

A. GENERAL CONSIDERATIONS
The following development is intended to show:

(1) that the level of melanin is a fundamental racial characteristic;
(2) that this rate can very well be measured in practice by various methods in the laboratory for all races and for living or dead beings.

We then applied the method to a few Egyptian mummies preserved in the anthropological laboratory of the Musée de l’Homme in Paris, thanks to the kindness of Mrs. CHAMLA, head of the department, and her aides. We used the technique of thin sections observed in ultraviolet or natural light; The preparations were graciously prepared by Mrs. J. GUILLEN, a technician in the physiology laboratory of the Faculty of Sciences of Dakar and Mr Mamadou CISSE, in charge of the IFAN Vertebrate Department. The results speak for themselves: first of all, contrary to widespread opinion1 , mummification processes do not destroy the epidermis to the point of rendering the method inapplicable in most cases. In particular, it would make it possible to analyze the skin of all the royal mummies of the Cairo Museum in perfect state of preservation: Thutmosis III, founder of the XVIIIth dynasty, the conqueror of all Western Asia, Sethi (Seti) I the founder Of the XIXth Dynasty, his son the famous Rameses II. The game would be worth the candle, and that’s why I tried to get samples to analyze. The Curator of the Cairo Museum, Dr. RYAD (Riyadh?), had promised to send me, but I have been waiting for more than a year.

I am surprised, however, that such an analysis has not already been attempted and carried out by other researchers for a very long time. In any case, we can say that such an examination undoubtedly reveals an unknown melanin level in leucoderm races and undoubtedly classifies ancient Egyptians among Africans of Black Africa.

Let us make some general remarks before discussing the purely technical exposition of the method.

It should be noted at the outset that even today’s Egyptians, after so many millennia of crossbreeding, still belong to the blood group B of the Negroes of West Africa 2 except group A2, except for the present inhabitants of The delta region that have obviously come from elsewhere.

Since the blood groups of the last prehistory men can in some cases be determined from their skeletons and the remains of their mummies, there is a possibility of studying migration.

The blood group A, is of importance to anthropology. It is characteristic of whites of European origin 3, and is not found in principle in colored races, in Negroes in particular.

The Gloger rule states that in warm-blooded higher animals the melanin pigmentation tends to grow with a. Heat and humidity. A high degree of moisture, combined with a high degree of heat causes black pigmentation. The maximum pigmentation being in the warm regions of the equator and the minimum at the Arctic Circle. The same scale seems to be valid for man 4

On the other hand, the triumph of the thesis of the monogenetic origin of mankind obliges us to reconsider all ethnic problems from a new angle. In drawing all the consequences of this fact, it must be admitted that all other races are born of the Negro race perhaps from a differentiation of the man from Grimaldi in Europe. The present laws of heredity would not oppose it. Quantum chemistry even attempts to formulate the law of biological mutations, or in any case to give a satisfactory scientific explanation 5. The Grimaldi would have passed through Gibraltar and Spain as the man of the Acheulean would have done. Another fairly probable parallel route would be through Tunisia, Sicily and southern Italy. A humanity born under the latitude of the Great Lakes must, according to what follows, be pigmented and black on the functional role of pigmentation, and according to the rule of GLOGER. If this hypothesis is to be taken into account (and it is difficult to see how the present state of scientific research could be escaped), the picture of the evolution of the human species would be as follows: a strongly pigmented Negroid Homo sapiens (GLoGER’s law) would have moved from the Great Lakes region (Kenya, Ethiopia, Uganda) to populate the rest of the world by migration. For Dr. LEAKEY, not only Homo faber but Homo sapiens-sapiens was also born in Black Africa at least 150,000 years ago 6. We believe that this man would have gained Europe, not by the Suez isthmus and the periphery of the Eastern Mediterranean where his traces are non-existent, but by the Sahara, Spain or Italy, which gives a singular importance The rock paintings that mark this voice and, it must be said, raises problems of chronology. But they are in the process of finding a scientific solution. In fact, they were the consequence of a sort of curse which the eminent French scholar Vaufrey had thrown upon Africa without making it on purpose: “Africa is lagging behind,” he had written; From then on, it became a sacrilege to attribute an age of any age to anything in black Africa. Nothing here could be connected chronologically to anything in Europe. But here is the advent of absolute chronology (potassium-argon, C-14, etc.) which restores the rights of science against the prejudices of scientists, hence the triumph of the monogenetic origin of man with localization The cradle of humanity in Africa: it was the potassium-argon method and related methods that made this feat possible. It is even known that men probably of the species Sapiens exploited the oldest mine in the world 40 000 years ago in Swaziland 7 to extract red ocher. But leaving the latter aside to return to that of the Homo sapiens of Kenya, their antiquity (they are anterior “Grimaldi and the man of Combe-Capelle) makes plausible the idea of a migration to Europe from Homo sapiens negroides (the Grimaldian in this case) in the Upper Palaeolithic.

The prehistoric African facts could very well explain those of Spain and the south of France, all prejudice apart. Two difficulties would remain:

(A) The Saharan chronology should one day provide dates for the Upper Palaeolithic and not only for the Neolithic in particular with regard to rock art: It may be assumed that a more detailed, more thorough and methodical study of the facts Could also change our thinking on this serious issue.

(B) The difficulty that prehistoric man would experience in crossing the Straits of Gibraltar.

In the VII. Congress of Prehistory (Addis Ababa, 1971), the typologist, Tixier, spoke of the nervousness of the lower Palaeolithic specialists whenever they contemplate the implications of the presence of the poultry (this typically African industry) in the south Of Europe, excluding the northern regions.

In fact, the idea is that in the remote period of the lower Palaeolithic, Homo faber, the man of Acheulean was already sufficiently equipped to cross the Straits of Gibraltar, much less, Grimaldi’s man of the Paleolithic era could have carried out such a feat. If such was the path followed, how to explain racial differentiation, in the present case the appearance of white or Cro-Magnon man twenty thousand years ago in the Solutrean, that is to say ten thousand years after the arrival of the Negroid Grimaldi in Europe. The problem is posed, science will answer it, but science is scientifically merited to our mind with the triumph of the monogenetic thesis. The account that we have given of the colloquium on the appearance of Homo sapiens, and the ideas which could be put forward prudently on this question8 concerning the probability of mutations with a change of environment. The Grimaldi, who is in any case an invading Negroid, is the first occupant of European soil as Homo Sapiens-Sapiens and the first white appeared 10,000 years after his arrival. We may assume a mutation due to the change in physical, climatic conditions in particular, for we are in full glacial period and negroes or negroids, transplanted under such conditions for such a period of time, may well change in appearance.

GRIMALDI GROTTE DES ENFANTS
FIG. 1. — Coupe de la Grotte des Enfants à Grimaldi, d’après Boule & Vallois. les Hommes fossiles, p. 298. N, niveau primitif du sol; F, foyers ; + 1, point où gisaient les Négroïdes ; + 2, + 3, points où gisaient les squelettes du type de Cro-Magnon.

The distinctly negroid characters of the Cro-Magnon of Spain, the nigritic osteology of the first Cro-Magnon men of France, the late appearance of this white, the still later one of yellow (the man of Chancelade ) to the Magdalenian 15,000 years ago, so many facts that did not receive a rational explanation, become more intelligible to us in the light of this hypothesis.

Western scholars have already expressed similar ideas. This is the case of Sanfourche quoting Goury: –

“On the other hand, the Palaeolithic works of art clearly situate the peak of the civilization of this remote state in Western Europe, especially in the Aquitano-Cantabrian region. Manifestated from the Aurignacian as one of the first creations of the Homo sapiens, art develops in Solutreen to magnificently flourish in the Magdalenian. During this long period, it is still the West that is the initiator, or at least the transmitter of a civilization coming perhaps from the South, that is to say from North- Western region. This is what Professor GOURY thinks: “A civilization stemming from the African land, that would upset the principles so far! The classical tradition has never ceased to affirm that all ancient civilizations come from the East. We are so impregnated with traditions erected in dogmas that an African civilizational nucleus seems incomprehensible to us … What we are able to affirm is that the first current of people to whom we owe our Lower Aurignacian comes from ” Africa by Spain, and no doubt also by Italy. 9

Be that as it may, one sees that the moment is not far when the learned world will admit that the black race is the first race of Homo sapiens to exist; All the others are derived from it by a process that science will specify. It is no longer necessary to populate Black Africa and Egypt at the beginning of time by mysterious whites or non-negro races.

B. TECHNICAL PART

In the current state of research, the authors (R. A. Nicolaus) distinguish three kinds of melanins.

(1) eumelanin or true melanin (black);

(2) phaeomelanin or brown, yellow melanin;

(3) Allomelanin or other melanins consisting of pigments which vary from brown to yellow.

The first two varieties are found chiefly in the animal kingdom, while the latter predominates in the vegetable kingdom.

Eumelanin is responsible for the color of the skin and hair. Tyrosine is the precursor of eumelanins. Black pigments are generally formed from the oxidation of diphenols such as dihydroxyphenylalanine (DOPA), 5-6 dihydroxyindole, catechol and 1-8 dihydroxynaphthalene, where quinone nuclei are formed with many active centers for polymerization. This is a necessary condition for obtaining a black pigment. Compounds in which the number of active centers is limited produce brown, brown, yellow-brown10 pigments.

The relative insolubility of melanins makes their study delicate, as it becomes difficult to purify them. On the other hand, they are of remarkable stability, and melanin has been found on fossil specimens dating back 150 million years11; They can be heated to 600º without decomposition.

According to R. A. Nicolaus, modern methods of physico-chemical analysis can not be used for the study of the structure of melanins. In fact, these absorb both in the ultraviolet and the visible violet without characteristic band. The spectroscopic study by nuclear magnetic resonance is very difficult. The infrared spectrum is irrelevant and the X-ray diffraction spectrum has just shown that the structure is not crystalline. The spectroscopic study by electron spin resonance revealed the free radical property of melanins. The study of degradation products yielded interesting results.

The tracer method, which is to mark C-14 for example, a precursor like tyrosine, is full of promises. It has already made it possible to follow the formation of melanin in the hair, etc.

Among the different pigments that contribute to the formation of skin color, carotene, oxyhemoglobin, reduced hemoglobin, melanin, the latter plays the role of primary racial factor in pigmentation of the skin of different breeds. Special cells called melanocytes are responsible for the formation of melanin in the “dermis” and especially in the human epidermis. Their number is relatively independent of the breed, but their activity, ie the amount of melanin they can make, depends on a racial factor linked to the genetic code: in other words, the negro has the same number of melanocytes as white and albino, for a given region of the skin but, its cells being much more active, will produce more grains of melanin than those of white due to the activity of tyrosinase, an enzyme which controls the formation of melanin. The melanocytes are found in the malpighi layer of the epidermis, 1035 per mm2 in the negro.12. It appears that there is no qualitative difference in melanin in passing from one breed to the other, but only in rate variations.

The development of melanin generally requires three elements: the substrate (tyrosine or DOPA), the enzyme catalyst for the oxidation reaction of the substrate and oxygen.

The reaction depends on several factors, temperature, pH, oxidation-reduction potential, and presence of enzyme inhibitor such as sulfur-containing reducing functional groups.

Tyrosinase-inhibiting biochemicals all contain the functional group – N-C- and are potent reducing agents.
S

There is nevertheless a correlation between the size and morphology of the melanocytes and their activity. The protein supporting albino tyrosinases is genetically defective 13.

The gene responsible for albino acts via groups, reducing agents. It has been thought that the oxidation of 5-6 dihydroxyindole can be inhibited in albino animals by sulfur functional groups which are present in melanic melanocytes. The αMSH (melanin-stimulating hormone) β-MSH and ACTH (adrenocorticotropin hormone) stimulate the differentiation of non-pigmented melanoblast cells into pigmented melanocytes. The activity of tyrosinase is promoted by the hormonal secretion of the pituitary gland.

The electron resonance spin (e.s.r.) detected in natural melanins is attributed to the existence of free radicals trapped in the polymerized mass of the macromolecules. The paramagnetism of melanins would thus be explained; Same electron exchangers,

Formation DE LA MELANINE A PARTIR DE LA TYROSINE.png
Formation DE LA MELANINE A PARTIR DE LA TYROSINE

The electron resonance spin (e.s.r.) detected in natural melanins is attributed to the existence of free radicals trapped in the polymerized mass of the macromolecules. The paramagnetism of melanins would thus be explained; Same electron exchangers, Melanins may have a protective role for organ- ism against oxidation-reduction phenomena and trapping of free radicals that could disturb the metabolism of living cells. They could protect the skin from radiation by such mechanism. Melanins are probably a mixture of macromolecules formed by the copolymerization of
Different precursors. Hydrogen peroxide discolours eumelanin. Melanin is purified by:

1) washing with 1% HCl
2) hot extraction with acetone
3)Prolonged boiling in concentrated Hcl.

According to electron microscopic studies, two types of epidermal cells are responsible for skin pigmentation: melanocyte and squamous cell; The dendritic melanocyte produces melanin and distributes it to neighboring squamous cells. (P. DROCHMANS, pp. 155-156). Melanocytes contain tyrosinase, an enzyme that transforms tyrosine and more rapidly DOPA into melanin. This is dispersed in the form of grains in the cell and in its dendritic extensions. The melanocytes have an epidermal localization and those whose penkaryon plunges entirely into the dermis, remain separated by the dermal membrane. The squamous cells, thus pigmented, carry away the pigmentation during their evolution towards the surface of the epidermis.

Quantitative Determination Method.

The measurement of the color of the skin by spectrophotometry was carried out in America as early as 1939, on whites, Japanese. Hindus, Mulattoes and Negroes, the skins of corpses, and the results were conclusive14. The sum of the absorptions, transmissions and reflections of the different layers of the skin is characteristic of it; Five pigments and a dispersion factor play an important role: the melanoid must be added to the four already mentioned. A flap of black skin (25 square inches) is macerated in 5% KOH, melanin being soluble in dilute alkalis; The solution obtained is assayed by spectrophotometry; The analysis reveals a high absorption (without characteristic band however) at the beginning of the visible spectrum in the violet and a minimum absorption at the end of the spectrum in the red.
The transmission grows without rupture from violet to red. Melanin, like other pigments, obeys Beer’s law, that is, the logarithm of the transmission is directly proportional to the concentration.

FIG. 2. Résultats de la mesure de la couleur de la peau par spectrophotométrie
FIG. 2. Résultats de la mesure de la couleur de la peau par spectrophotométrie, d’après Adwards & Duntley, the pigments and color of living human skin.
I. Comparison of the skin of the buttocks of men of different “colors”.
II. Transmission through solutions of various concentrations of melanin in 5% KOH. Note the marked but gradual absorption at the violet end.
III. Transmission and reflection of the corneal layer of a corpse heel, As the horny layer is translucent (even more than in living organisms), transmission is strong and reflection is weak.
On the abscissa, wavelength in millimicrons,

The idea that racial differences in color are due solely to variations in the amount of melanin in the epidermis was confirmed by the observations made on dissolved melanin.

Melanin has an equivalent behavior under the skin and in solution.

The spectrophotometric properties of melanin, among others (absorption band in the visible violet) classify the melanoid as a degradation product of melanin.

The woman is generally less pigmented than the man of the same race.

The amount of melanoid formed always depends on the amount of melanin present and the storage depends on the thickness of skin, epidermis. Both varieties of blood hemoglobins have characteristic absorption bands and transmission peaks. The light is reflected by the epidermis, the dermis and the walls of the veins. The carotene has an absorption band in blue at 482 mμ. By dissolution and spectrophotometric analysis, it was possible to determine that the color of the fat is due to the carotene, which is also present in the thick parts of the epidermis.

All pigments have a predominant absorption in blue. The transmitted light contains a larger proton of long wavelengths (red) while the reflected light contains the short wavelengths (blue), this is a dispersion effect.

The racial differences are explained by the quantities of melanin and melanoid, excluding other pigments, carotene, hemoglobin.

Ross Aiken Gortner studied the effect of alkalies on melanin and described the conditions for good extraction without decomposition with 0.2% sodium hydroxide. The melanin obtained is then soluble in acetic acid, formic acid or mineral acids having a concentration of less than N / 10. Otherwise losses easily reach 50%. Melanin decomposes as soon as the concentration of alkali exceeds the content of 0.2%, according to this author who observes: “a black product can be obtained from black wool by any method”15. If the pigment is well prepared the combustion does not leave ash and the H, C, N, S, O. rates can then be determined according to the conventional methods of analysis: combustion in an oxygen stream, Dumas method For nitrogen, etc.

A.J. Lea relates the solubility of all varieties of melanin in cold ethylene chlorohydrin: it does not appear to be a combination with the so-called solvent, as is the case with diethylamine, because The residual product after evaporation retains all the properties of melanin 16.

A good resolution of melanin grains can be obtained by microscopic observation in ultraviolet light by thin sections fixed to glutaraldehyde and post-fixed with osmium tetroxide17.

V. VILTER remarks that: “the larvae of Amblystoma mexicanum change color according to the conditions of brightness or according to the color of the background on which they develop. This phenomenon of chromatic adaptation is subject to the control of the nervous system through vision. ”

The stay of the larvae on a black background provokes the gradual darkening of the color of the integuments. The melanophores of the segmental melanic spots of the young larvae spread out considerably, which determines the more intense tint and the gradual confluence of these spots.

The Axolotls, which are made to remain on a white ground, exhibit a coloration of the integuments, which gradually becomes lighter in young larvae, and the segmental patches gradually diminish in extent and intensity owing to the contraction of the melanophores. If one prolongs the stay on a white ground, the melamic pattern is soon represented only by small rounded patches of greyish color clearly separated from one another18.

An Austro-American group of researchers has recently stated that the color of the skin depends particularly on the regular distribution of melanotomes, a phenomenon more pronounced in black than in any other breed.

CONCLUSION

It is clear from the foregoing that physical anthropology thus has a method that is both powerful and fine, practicable whenever the animal or human remains to be analyzed include flaps of skins: this method is therefore also applicable to the A protohistoric race from Egypt studied by Elliot Smith who often harvested pieces of skins. Perhaps one could also re-examine Serge’s “brown” race, which populated the entire Mediterranean periphery with protohistory and which is complacently identified with the protodynastic Egyptian race?

The power of the method of analysis described above contrasts with the rarity of its use. However, its fineness must not lead to the excesses of molecular anthropology which allowed the classification of two twin brothers in different racial categories. Strictly speaking, the samples of skins analyzed should have undergone an identical treatment: a freshly harvested skin (of Negro or other) should have undergone beforehand a mummification process which, by partially destroying the epidermis, would leave especially the nuclei of the melanocytes In the form of inclusions in the tissues separating the dermis and the epidermis: in this case only the melanin contents would be strictly comparable.

Footnotes
1. Thomas J. Pettigrew, Pettigrew’s history of Egyptian mummies, London, 1934. G. Elliot SMITH and W. R. Dawson: Egyptian mummies, London, 1924.
2. Ashley Montagu, an Introduction to Physical Anthropology, third. ed., 1960,
Charles C. Thomas Publisher, Illinois (USA), p. 337
3. MoNTAGU, ор. cit., p. 344
4. Op, cit, p. 366.
5. Op cit, p. 390.
6. PULLMANN B. & A…: Quantum biochemistry Inter science.
7. Cheikh Anta Drop : L’apparition de l’Homo sapiens, Bull. IFAN, tome XXXII, série B, no 3, 1970.
8. Leakey : rapport (sous presse) du VIIe Congrès Panafricain de préhistoire à Addis Abeba (1971).
9. Cheikh Anta Diop : L’apparition de l’Homo Sapiens: Bull, IFAN, t. XXXII, série B.
10. Cheikh Anta Diop, op. Cit,
11. La fin du Néolithique et l’apparition des métaux, Revue de la métallurgie, n° 8 1954 par A. A. Sanfourche.
12. R. A. Nicolaus : Melanins, Paris, Hermann 1968.
13. R. A. Nicolaus, op. cit., р- 11
14. L’identité antomique et de nombre des organes de la pigmentation chez toutes les races militerait pour une origine monogénétique de l’humanité : la différence de la pigmentation étant d’origine purement physiologique et fonction du climat.
15. Nicolaus, op. cit., р 12
16. Lucia T.Y. Chian Elal : Tyrosinas inhibitor : its role in suntanning and albinism in Science, vol. 155, p. 138 et suivantes.
17. Edward A. et. coll. The Pigments and color of living human skin: in American Journal of anatomy, vol. 65, no. 1, juillet 1939.
18. Ross Aiken Gortner. Effect of Alkali on Melanin, p. 346.
19. LEA A. J. Nature, vol. 156, p. 478, 20 octobre 1945.
20. Κ. Κ. Μυstakalliο et al, Dermatologica (1967), p. 134, 187, 190. Resolution of melanin granules and epidermal cell types by U.V. television microscope and by high contrast phase microscopy of electron microscopic section.
21. V. VILTER : Modification du système mélanique chez les Axolotls soumis l’action des fonds blancs et noirs. Société de biologie, 1931, p. 774 et suivantes.