I’m currently reading Nicholas Wade’s A Troublesome Inheritance: Genes, Race and Human History, and it’s an outstanding read. He succinctly puts the science of racial differences so it’s easy for the lay person to understand. I’ve come across a part in the book where he talks about race and body odor. In the past, I’ve gotten into discussions on how and why different races have different body odors. My article Gene Expression by Race is great to get up to speed on the differences I’ve already written on in regards to the races of man.
Robert Lindsay has a good post on race and body odor, but I thought I’d add more information to how and why these differences exist.
East Asians have thicker hair than do Africans and Europeans. The gene, called ‘EDAR‘, is present in both Africans and Europeans, however a different type of this allele is widespread in East Asian populations (Han Chinese, 93 percent; Japan and Thailand about 70 percent and 60 to 90 percent in ‘Native’ Americans [which makes sense since we know that they branched off of Siberians around 10kya]). This allele is called “EDAR-V370A” since the V (valine) and A (alanine) switched on the “370th codon” (Wade, 2015: 88).
East Asians who carry this allele have thick and shiny hair. However, correlation is not causation, blah blah blah. So researchers genetically modified a strain of mice whose EDAR gene was converted into the form that East Asians carry. The results were shocking. The mice with the East Asian EDAR variant had thicker fur, and more eccrine glands in their footpads. Sweat glands come in two forms–eccrine glands which secrete water to cool the body and apocrine glands which secrete proteins and hormones (Wade, 2015: 89). Looking at the Chinese, we can see that they do carry significantly more eccrine glands!! Moreover, the mice also had smaller breasts. If East Asians had this EDAR variant then, logically speaking, they would have smaller breasts and what do you know: they do! This is, most likely, the reason why East Asians have smaller breasts than Africans and Europeans.
Another prominent effect of the EDAR variant that East Asians carry is the proclivity for shoveled teeth. When viewed from the back, East Asian teeth look ‘shovel-shaped’. The reason that this single gene is able to effect a lot of the phenotype is because this gene is active early in development. “EDAR has a great influence on the body because it’s switched on so early in embryonic development and helps shape organs such as the skin, teeth, hair and breasts” (Wade, 2015: 89).
Why does this singular gene have so many effects? One posited reason is thick hair and small breasts were admired by men (and thick hair for women) and this is what drove the selection (sexual selection). Another possibility, says Wade “is that many or all of the effects of EDAR-V370A were advantageous at one time or another, and that natural selection favored each in turn” (Wade, 2015: 90).
Turning our attention to Africans, they have more eccrine sweat glands, and, in comparison to East Asians, Africans have wider pores in their skin. Due to this, blacks have a stronger scent when sweating than East Asians. Conversely, East Asians have smaller pores.
I no longer have access to the source of this next quote, however, I have parts of the text saved:
There are fewer apocrine glands in Orientals and Native American Indians than in Blacks and Whites. Apocrine glands excrete fat and protein along with water (Poirier et al p 567).
The amount of chloride excreted by sweat glands varies by race: Blacks have more chloride in sweat than do whites. Acclimatized Whites excrete less chloride than unacclimatized whites– a useful adaptation (text 452). Water loss can be considerable: in extreme temperatures young males can loose 4 liters per hour. Thus, human ancestors in tropics must have always had ready access to water (see Overfield for many details).
So since apocrine sweat glands excrete more fats and proteins along with water, this explains why the two races differ in smell in comparison to East Asians. It also makes sense that ‘Native’ Americans would have fewer apocrine glands than Caucasians and Africans since they split off of East Asians around 10-15 kya. You can also see that blacks have more chloride in their sweat. Now, I’ve never encountered this myself, but I’ve seen numerous people say that blacks smell worse than whites or East Asians. This does have a biological basis, and it has to do with pore size, pore type and amount of chloride excreted by the sweat glands.
Of course, like with a lot of traits (not all), whites fall in the middle.
“Almost all Europeans have and all Africans have the wet earwax allele of the ABCC11 gene. The sharp differentiation of the two alleles implies a strong selection pressure.” (Wade, 2015: 90) The function of earwax is to prevent bugs from flying in the ear. Obviously, if the wax is wet (like Africans and Caucasians), the bug won’t be able to get too far into the ear before it gets stopped by the wet earwax. And as luck would have it, the two alleles of the ABCC11 gene are involved in the apocrine sweat glands (Wade, 2015: 90).
The apocrine sweat glands, unlike the eccrine glands, are restricted to the nipples, eyelids, armpits and other special areas on the body. These glands make slightly oil secretions, the specialty of which is to secrete earwax. The glands are odorless, but begin to cause a smell after bacteria begins decomposing dead skin cells(Wade, 2015: 90-91).
East Asians, having the dry earwax allele produce fewer excretions from their apocrine glands and, thusly, have less body odor. “Among people spending many months in confined spaces to escape the cold, lack of body odor would have been an attractive trait and one perhaps favored by sexual selection.” (Wade, 2015: 91) I love this!! It makes so much sense. East Asians were already selected for smaller sweat glands which, along with their dry earwax, produce less of a strong smell when they are perspiring.
Wade further goes into the earwax/body odor relationship and states that the dry earwax allele is almost universal in north China “but yields to the wet allele toward the south.” (Wade, 2015: 91) Most, but not all East Asians have the dry earwax allele, as well as the EDAR-V370A allele.
For a final point, it is assumed that all races have roughly the same skin structure. HOWEVER, morphological differences exist between the races. To quote Ruche and Cesarini (1992):
Under the microscope skin structure is roughly the same in all races, but morphological differences exist, particularly within the epidermis, with potential practical consequences. In comparison with white skin, the black skin stratum corneum is equal in thickness but more compact: about twenty cell layers are observed in blacks versus sixteen layers in whites. The lipid content of black epidermis is also somewhat higher, and this perhaps explains the greater cellular cohesion, hence the difficulty in stripping off the black horny layer. These findings could also explain a slightly inferior permeability of black skin to certain chemicals. The hair of blacks in naturally more brittle and more susceptible to breakage and spontaneous knotting than that of whites. The kinky or wooly form of black hair, the weak intercellular cohesion between cortical cells and the specific hair grooming practices among black people account for these effects. The higher electrical resistance of black skin suggests that the black epidermis would be less hydrated than white epidermis. Anatomically, the amount of sweat glands in black and white skins is identical and varies with climatic changes but not with racial factors. Likewise, sweating is thought to be similar in both races, taking into account the contradictory results from studies, but black subjects withstand humid heat better while whites cope better with dry heat.
So racial factors have no bearing on this, but climatic changes do. Generally, Africans come from humid climates nearer to the equator while Europeans come from cooler places farther from the equator. So we can say that, technically, there is a racial variation between the two.
And from this website on body odor:
Excessive sweating is a more common problem for Caucasians and Africans, who tend to have more hair follicles to which the apocrine glands are attached. East Asian people appear to have less and smaller apocrine glands, which explains why they might not need to use deodorants as often as populations of Africa and Europe (see paragraph below). As a matter of fact the deodorant/antiperspirant market in Asia is much smaller than in the western world. Surely, though, there may be many exceptions since body odour is obviously influenced by many factors, for example by one’s personal diet (spicy asiatic food etc.).
Below this section, the article talks about earwax and body odor, which I have covered above.
Differing allele frequencies between the races of man produce differing phenotypes based on where that groups’ ancestors evolved. Changes in certain alleles and not in others clearly led to differences in phenotype that did not occur because the environment was different between the races. These pheno and genotypic differences *prove the existence of race*, along with modern-day genomic testing. The fact that the races differ, albeit subtly, on numerous traits proves the existence of race, population, whatever you want to call it. It doesn’t change race’s reality.
If you have not read it, buy it!!! You’ll be a better and sharper race-realist as Nicholas Wade is an outstanding researcher and can explain complex concepts very simply.