The Descent of Man – Day 49 of 151

On the Formation of the Races of Man

In some cases the crossing of distinct races has led to the formation of a new race. The singular fact that the Europeans and Hindoos, who belong to the same Aryan stock, and speak a language fundamentally the same, differ widely in appearance, whilst Europeans differ but little from Jews, who belong to the Semitic stock, and speak quite another language, has been accounted for by Broca (49. ‘On Anthropology,’ translation, ‘Anthropological Review,’ Jan. 1868, p. 38.), through certain Aryan branches having been largely crossed by indigenous tribes during their wide diffusion. When two races in close contact cross, the first result is a heterogeneous mixture: thus Mr. Hunter, in describing the Santali or hill-tribes of India, says that hundreds of imperceptible gradations may be traced “from the black, squat tribes of the mountains to the tall olive-coloured Brahman, with his intellectual brow, calm eyes, and high but narrow head”; so that it is necessary in courts of justice to ask the witnesses whether they are Santalis or Hindoos. (50. ‘The Annals of Rural Bengal,’ 1868, p. 134.) Whether a heterogeneous people, such as the inhabitants of some of the Polynesian islands, formed by the crossing of two distinct races, with few or no pure members left, would ever become homogeneous, is not known from direct evidence. But as with our domesticated animals, a cross-breed can certainly be fixed and made uniform by careful selection (51. ‘The Variation of Animals and Plants under Domestication,’ vol. ii. p. 95.) in the course of a few generations, we may infer that the free intercrossing of a heterogeneous mixture during a long descent would supply the place of selection, and overcome any tendency to reversion; so that the crossed race would ultimately become homogeneous, though it might not partake in an equal degree of the characters of the two parent-races.

Of all the differences between the races of man, the colour of the skin is the most conspicuous and one of the best marked. It was formerly thought that differences of this kind could be accounted for by long exposure to different climates; but Pallas first shewed that this is not tenable, and he has since been followed by almost all anthropologists. (52. Pallas, ‘Act. Acad. St. Petersburg,’ 1780, part ii. p. 69. He was followed by Rudolphi, in his ‘Beytrage zur Anthropologie,’ 1812. An excellent summary of the evidence is given by Godron, ‘De l’Espece,’ 1859, vol. ii. p. 246, etc.) This view has been rejected chiefly because the distribution of the variously coloured races, most of whom must have long inhabited their present homes, does not coincide with corresponding differences of climate. Some little weight may be given to such cases as that of the Dutch families, who, as we hear on excellent authority (53. Sir Andrew Smith, as quoted by Knox, ‘Races of Man,’ 1850, p. 473.), have not undergone the least change of colour after residing for three centuries in South Africa. An argument on the same side may likewise be drawn from the uniform appearance in various parts of the world of gipsies and Jews, though the uniformity of the latter has been somewhat exaggerated. (54. See De Quatrefages on this head, ‘Revue des Cours Scientifiques,’ Oct. 17, 1868, p. 731.) A very damp or a very dry atmosphere has been supposed to be more influential in modifying the colour of the skin than mere heat; but as D’Orbigny in South America, and Livingstone in Africa, arrived at diametrically opposite conclusions with respect to dampness and dryness, any conclusion on this head must be considered as very doubtful. (55. Livingstone’s ‘Travels and Researches in S. Africa,’ 1857, pp. 338, 339. D’Orbigny, as quoted by Godron, ‘De l’Espece,’ vol. ii. p. 266.)

Various facts, which I have given elsewhere, prove that the colour of the skin and hair is sometimes correlated in a surprising manner with a complete immunity from the action of certain vegetable poisons, and from the attacks of certain parasites. Hence it occurred to me, that negroes and other dark races might have acquired their dark tints by the darker individuals escaping from the deadly influence of the miasma of their native countries, during a long series of generations.

I afterwards found that this same idea had long ago occurred to Dr. Wells. (56. See a paper read before the Royal Soc. in 1813, and published in his Essays in 1818. I have given an account of Dr. Wells’ views in the Historical Sketch (p. xvi.) to my ‘Origin of Species.’ Various cases of colour correlated with constitutional peculiarities are given in my ‘Variation of Animals and Plants under Domestication,’ vol. ii. pp. 227, 335.) It has long been known that negroes, and even mulattoes, are almost completely exempt from the yellow-fever, so destructive in tropical America. (57. See, for instance, Nott and Gliddon, ‘Types of Mankind,’ p. 68.) They likewise escape to a large extent the fatal intermittent fevers, that prevail along at least 2600 miles of the shores of Africa, and which annually cause one-fifth of the white settlers to die, and another fifth to return home invalided. (58. Major Tulloch, in a paper read before the Statistical Society, April 20, 1840, and given in the ‘Athenaeum,’ 1840, p. 353.) This immunity in the negro seems to be partly inherent, depending on some unknown peculiarity of constitution, and partly the result of acclimatisation. Pouchet (59. ‘The Plurality of the Human Race’ (translat.), 1864, p. 60.) states that the negro regiments recruited near the Soudan, and borrowed from the Viceroy of Egypt for the Mexican war, escaped the yellow-fever almost equally with the negroes originally brought from various parts of Africa and accustomed to the climate of the West Indies. That acclimatisation plays a part, is shewn by the many cases in which negroes have become somewhat liable to tropical fevers, after having resided for some time in a colder climate. (60. Quatrefages, ‘Unite de l’Espece Humaine,’ 1861, p. 205. Waitz, ‘Introduction to Anthropology,’ translat., vol. i. 1863, p. 124. Livingstone gives analogous cases in his ‘Travels.’) The nature of the climate under which the white races have long resided, likewise has some influence on them; for during the fearful epidemic of yellow fever in Demerara during 1837, Dr. Blair found that the death-rate of the immigrants was proportional to the latitude of the country whence they had come. With the negro the immunity, as far as it is the result of acclimatisation, implies exposure during a prodigious length of time; for the aborigines of tropical America who have resided there from time immemorial, are not exempt from yellow fever; and the Rev. H.B. Tristram states, that there are districts in Northern Africa which the native inhabitants are compelled annually to leave, though the negroes can remain with safety.

That the immunity of the negro is in any degree correlated with the colour of his skin is a mere conjecture: it may be correlated with some difference in his blood, nervous system, or other tissues. Nevertheless, from the facts above alluded to, and from some connection apparently existing between complexion and a tendency to consumption, the conjecture seemed to me not improbable. Consequently I endeavoured, with but little success (61. In the spring of 1862 I obtained permission from the Director-General of the Medical department of the Army, to transmit to the surgeons of the various regiments on foreign service a blank table, with the following appended remarks, but I have received no returns. “As several well-marked cases have been recorded with our domestic animals of a relation between the colour of the dermal appendages and the constitution; and it being notorious that there is some limited degree of relation between the colour of the races of man and the climate inhabited by them; the following investigation seems worth consideration. Namely, whether there is any relation in Europeans between the colour of their hair, and their liability to the diseases of tropical countries. If the surgeons of the several regiments, when stationed in unhealthy tropical districts, would be so good as first to count, as a standard of comparison, how many men, in the force whence the sick are drawn, have dark and light-coloured hair, and hair of intermediate or doubtful tints; and if a similar account were kept by the same medical gentlemen, of all the men who suffered from malarious and yellow fevers, or from dysentery, it would soon be apparent, after some thousand cases had been tabulated, whether there exists any relation between the colour of the hair and constitutional liability to tropical diseases. Perhaps no such relation would be discovered, but the investigation is well worth making. In case any positive result were obtained, it might be of some practical use in selecting men for any particular service. Theoretically the result would be of high interest, as indicating one means by which a race of men inhabiting from a remote period an unhealthy tropical climate, might have become dark-coloured by the better preservation of dark-haired or dark-complexioned individuals during a long succession of generations.”), to ascertain how far it holds good. The late Dr. Daniell, who had long lived on the West Coast of Africa, told me that he did not believe in any such relation. He was himself unusually fair, and had withstood the climate in a wonderful manner. When he first arrived as a boy on the coast, an old and experienced negro chief predicted from his appearance that this would prove the case. Dr. Nicholson, of Antigua, after having attended to this subject, writes to me that dark-coloured Europeans escape the yellow fever more than those that are light-coloured. Mr. J.M. Harris altogether denies that Europeans with dark hair withstand a hot climate better than other men: on the contrary, experience has taught him in making a selection of men for service on the coast of Africa, to choose those with red hair. (62. ‘Anthropological Review,’ Jan. 1866, p. xxi. Dr. Sharpe also says, with respect to India (‘Man a Special Creation,’ 1873, p. 118), “that it has been noticed by some medical officers that Europeans with light hair and florid complexions suffer less from diseases of tropical countries than persons with dark hair and sallow complexions; and, so far as I know, there appear to be good grounds for this remark.” On the other hand, Mr. Heddle, of Sierra Leone, “who has had more clerks killed under him than any other man,” by the climate of the West African Coast (W. Reade, ‘African Sketch Book,’ vol. ii. p. 522), holds a directly opposite view, as does Capt. Burton.) As far, therefore, as these slight indications go, there seems no foundation for the hypothesis, that blackness has resulted from the darker and darker individuals having survived better during long exposure to fever-generating miasma.

Dr. Sharpe remarks (63. ‘Man a Special Creation,’ 1873, p. 119.), that a tropical sun, which burns and blisters a white skin, does not injure a black one at all; and, as he adds, this is not due to habit in the individual, for children only six or eight months old are often carried about naked, and are not affected. I have been assured by a medical man, that some years ago during each summer, but not during the winter, his hands became marked with light brown patches, like, although larger than freckles, and that these patches were never affected by sun-burning, whilst the white parts of his skin have on several occasions been much inflamed and blistered. With the lower animals there is, also, a constitutional difference in liability to the action of the sun between those parts of the skin clothed with white hair and other parts. (64. ‘Variation of Animals and Plants under Domestication,’ vol. ii. pp. 336, 337.) Whether the saving of the skin from being thus burnt is of sufficient importance to account for a dark tint having been gradually acquired by man through natural selection, I am unable to judge. If it be so, we should have to assume that the natives of tropical America have lived there for a much shorter time than the Negroes in Africa, or the Papuans in the southern parts of the Malay archipelago, just as the lighter-coloured Hindoos have resided in India for a shorter time than the darker aborigines of the central and southern parts of the peninsula.

Post a Comment

Your email is never published nor shared. (To tell the truth I don't even really care if you give me your email or not.)