Human evolution theory utilizing concepts of neoteny & female sexual selection
An etiology of neuropsychological disorders such as autism and dyslexia, and the origin of left handedness.

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 Library of Excerpts

Africans and African-Americans: Heterochronic Patterns


"In Western clinical populations, a marked diurnal variation in serum T levels has been reported, with evening values averaging around 30% lower than morning values (Nieschlag, 1974). Baseline values of !Kung hunters show similar diurnal variation." (Worthman, Carol M. & Konner, Melvin, J. (1987) Testosterone levels change with subsistence hunting effort in !Kung San men. Psychoneuroendocrinology 12(6): pp. 452)

"Handedness and sex are also significantly related for several subgroups: whites (p<0.0001), blacks (0.04), younger respondents (0.0001), older ones (0.0003), younger whites (0.0003), and younger blacks (0.02; Table 2 and 3). For all subgroups except all blacks, the pattern is similar to that reported in Table 1. For all blacks, there are proportionally more males in the Mixed categories, and more females in the two extremes: Lefts or Rights." (Lansky, LM, Feinstein H, & Peterson JM (1988) Demography of handedness two samples of randomly selected adults (N = 2083). Neuropsychologia 26: 468)

"Subtracting facial length, Broca obtained the following figures for anterior cranium: 78.351 for whites, 72.628 for blacks. In other words, based on the cranium alone, the foramen magnum of blacks lay farther forward (the ratio of front to back, calculated from Broca's data, is .781 for whites, and .720 for blacks). Clearly, by criteria explictly accepted before the study, blacks are superior to whites. Or so it must be, unless the criteria suddenly shift, as they did forthwith." (Gould 1996: 134, The Mismeasure of Man)

"Two approaches are possible. First, extensive comparisons have already been made of sexual dimorphism between human populations of different geographic origins. these populations could also be compared with respect to breeding-system differences. Eveleth (1975) amd Eveleth and Tanner (1976), for example, compare a large number of populations of Europeans, Africans, Amerindians, Asians, and inhabitants of New Guinea in regard to sexual dimorphism in stature. Their conclusions are that Amerindians are the most dimorphic, followed by Asians and Europeans, with inhabitants of Africa and New Guinea more or less alike and the least dimorphic. Using recent history as the criterion, it would appear that African and New Guinea populations are the most polygynous of these five groups rather than the least as the demorphism data would suggest from comparisons with other mammal groups." (Alexander R.D., et. al. (1979) Sexual Dimorphisms and Breeding Systems in Pinnipeds, Ungulates, Primates, and Humans. In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 417)

"The MCR [metabolic clearance rate] of testosterone is mainly influenced by environmental factors rather than genetic whereas the PR [production rate] of testosterone is affected by genetic factors. Those findings and the results of this study suggest that environmental factors may account for the elevated MCR of testosterone observed in men with protatic cancer rather than a gentic factor. The patients and controls undoubtedly have a familial contribution to the plasma antrogen levels, and their PR of DHT and testosterone. It therefore appears that hereditary factors could regulate the PR of testosterone in men who develop prostatic cancer. .. Men with apparent stress and evidence of dissemination of the cancer were excluded as were those who had received endocrine therapy." (Meikle AW, Smith JA, Stringham JD(1989) Estradiol and testosterone metabolism and production in men with prostatic cancer. J Steroid Biochem 33(1):21)

“Plasma gonadotropin levels throughout the regular menstrual cycle in 10 Japanese women were measured daily using radioimmunoassay. At the peak of ovulation, mean FSH levels were 17.6 +/- 7.9 mlU/ml and mean LH levels were 75.2 +/- 26.0 mlU/ml. At midcycle, the mean gonadotropin levels were significantly lower in Japanese women than in Nigerian womenwho, as reported by Nylander (1973), had a high frequency of twinning. It is, therefore, suggested that the low frequency of dizygotic twinning in Japanese women might be related to their low output of gonadotropin. “ (Soma H, Takayama M, Kiyokawa T, Akaeda T, Tokoro K (1975) Serum gonadotropin levels in Japanese women. Obstet Gynecol 46 (3): 311)


[citations removed] "Five dietitians supervised the subjects to follow the experimental diet. The reduction in fat was realized by replacing the regular milk, butter, fatty meat, cheese and suasages by skimmed milk, vegetable oil, margarine (high P/S-ratio) fish, vegetables and fruit as described in detail previously. ... Indeed, the diet influenced the degree of protein binding of testosterone resulting in a small but uniform rise in the percentage of free testosterone fraction as measured utilizing the precipitation method of Bergink et al. Therefore, the calculated concentrations of free (non-protein bound) testosterone decreased less than that of total unconjugated hormone (P < 0.01). ... With regard to testosterone and androstenedione, which decreased 15 and 11% respectively our results show the same tendency as those in the study of Hill el al. However, they reported a more remarkable fall in testosterone in white subjects and the change of androstenedione in black subjects, was not statistically significant. ... Interestingly, there was a negative correlation between serum prolactin and androgens during the whole study. The hypogonadic effect of hyperprolactinemia in man is well-documented. There is evidence that prolactin may interfere with the gonadal steroidogenesis in rats and man and low levels of testosterone can occur without a gonadotrophin response." (Hamalainen E, Adlercreutz H, Puska P, Pietinen P (1984) Diet and serum sex hormones in healthy men. J Steroid Biochem 20(1):459-462)

"Epidemiologic data reveal that the incidence rate of prostate gland carcinoma among the black population in the United States (US) is several times higher than among Nigerians. A collaborative study between the two countries was undertaken, and blood hormone (testosterone [T], dihydrotestosterone [DHT], estrone [E1], estradiol [E2], and prolactin [P1]), total acid phosphatase (TP), and prostatic acid phosphatase (PAP) profiles in the two population groups were compared. In the US groups (patients and controls) there were significantly higher levels of T (P less than 0.01) and E1 (P less than 0.05) compared with the Nigerians. Also, the US patients had significantly higher levels of T (P less than 0.05) and E1 (P less than 0.01) compared with their matched controls. In the Nigerians T but not E1 levels were significantly lower (P less than 0.05) in patients compared with controls. DHT, E2, and P1 were not significantly different in patients and controls between and within the populations. Nigerian patients had higher levels (P less than 0.001) of TP and PAP compared with US patients. It is concluded that differences in blood hormone profiles in the two population groups are based on factors other than the genetic makeup of the populations." (Ahluvalia B, Jackson MA, Jones GW, Williams AO, Mamidanna SR, Rajguru S (1981) Blood hormone profiles in prostate cancer patients in high-risk and low-risk populations. Cancer 48: 2267)

"The differences in dizygotic twin frequency, and presumably ovulaton rate, are in the same direction as the differences in testis size. The frequencies of dizygotic twins are even higher (up to 49 per 1,000 births) among African blacks. ... Yoruba women, with the world's highest frequency of dizygotic twins, have higher FSH and LH levels at the time of ovulation than do Japanese women, who have the lowest frequency of dizygotic twins. This variation in female hormone levels may contribute to the distribution of the incidence of breast cancer, which is known to be related to oestrogen levels. Even after all other risk factors for breast cancer have been taken into account, the incidence among Japanese women remains inexplicably low. Perhaps this puzzel, the so-called 'Japanese factor' of (breast cancer, is related to the low double-ovulation frequencies and low hormone levels." Diamond, JM (1986) Variation in human testis size. Nature (London) 320: 488-489)

"...the American colored population is, in fact, at least one-fifth Caucasion in genetic composition (Roberts 1955)." Hulse, F.S. (1978) Group selection and sexual selection in human evolution. in Evolutionary models and studies (Hague) Meier, R., Otten, C.M., Abdel-Hameed, F. (eds.), Moulton Publisher, Paris.p. 33)

"The age-standardized incidence rate [carcinoma of the prostate] varies from a low of 2.7 / 100,000 among the Japanese in Osaka to a high of 77.0 / 100,000 among Afro-Americans in the San Francisco Bay area. A study of migrant workers showed that when people moved from an area of low cancer incidence to a high-incidence area their risk for the disease increased correspondingly, suggesting that factors other than genetic makeup of the population are involved." (Ahluvalia B, Jackson MA, Jones GW, Williams AO, Mamidanna SR, Rajguru S (1981) Blood hormone profiles in prostate cancer patients in high-risk and low-risk populations. Cancer 48: 2267)

[citations removed] "It is well known that androgens are required for normal development and maturation of the prostate gland, and hypertrophy of this gland does not occur in men castrated in later life. The date reported here imply that the prostate glands of Nigerian males as a group are consistently exposed to lesser amounts of androgens compared to US males and are therefore less stimulated to grow. However, it is clear that higher T levels alone cannot be the sole basis for the low incidence of this disease in Nigerians for two reasons--first, wide fluctuation in T levels was found within a population, and the fact that no significant differences in T levels in patients and their controls were found when arranged according to age and stage of the disease within each group cast doubt as to the validity of the conclusion. Although the US patients had higher levels of T (P<0.05) compared with their controls, the differences, while significant, appear to be too small in our opinion to provide sufficient basis to implicate T in the etiology of the disease. ... To our knowledge this is the first report showing blood hormone levels in two culturally divergent but genetically linked groups. Hil et al. (1976) reported a comparison of hormone profiles in low-risk Bantus and high-risk North American Caucasians in incidence of breast cancer. The results of the study showed a difference in adrenal activity in the two groups raising the possibility that dietary factors may be a contributory cause. That diet alone alters release of gonadotropins, and adrenal activity was reported. Ample evidence suggests that environmental factors including dietary habits and life style can alter the incidence of breast cancer. This is evident from data on migrant populations who move from low-risk to high-risk populations with high incidence of the disease. That diet with high animal protein content can initiante early menarch and is associated with increased risk of breast cancer is reported. ... Higher levels of TP and PAP in the Nigerian patients and a later stage of the disease is that population compared with US patients suggest a correlation of disease stage to levels of TP and PAP." (Ahluvalia B, Jackson MA, Jones GW, Williams AO, Mamidanna SR, Rajguru S (1981) Blood hormone profiles in prostate cancer patients in high-risk and low-risk populations. Cancer 48: 2271-1)

"Evolutionary arguments for the importance of hunting in shaping foundations of men's behavior have tended to focus on its aggressive, competitive and stressful components. Its basic nature as a form of effort, or work, has been less frequently considered. The data suggest that !Kung men do not experience subsistence hunting as mere stress, which depresses T levels, for its main effect was an increase in evening values. On the other hand, no interaction of hunt outcome and T levels were observed, in contrast to reports that T reflects success and failure in certain aggressive and dominance interactions. Rather, these data are most congruent with reported effects of moderate prolonged excercise." (Worthman, Carol M. & Konner, Melvin, J. (1987) Testosterone levels change with subsistence hunting effort in !Kung San men. Psychoneuroendocrinology 12(6): pp. 456)

"We conclude that subsistence hunting was associated with significant changes in testosterone patterns in !Kung hunters, due primarily to the maintenance of T concentrations during hunting days that is reflected in elevation of evening values. Diurnal variation in circulating T was hence markedly attenuated. It is also notable that shifts in T level were a consequence, not a primary cause, of the behaviors observed here; hormone changes followed and supported, not preceded, hunting activity. Studies of human behavioral biology might consider the ways in which the dominant context of human evolution, the hunting-gathering niche, may have selected for efficient, appropriate responses to subsistence-related effort." (Worthman, Carol M. & Konner, Melvin, J. (1987) Testosterone levels change with subsistence hunting effort in !Kung San men. Psychoneuroendocrinology 12(6): pp. 456)

"Of the total sample (N=1496) [Detroit], 7% were left-handed. The percentage of smokers among left-handers (78%) is significantly greater than among right-handers (60%, p < .0005). In Table1, data in the first column (non smokers) show that regardless of race and sex groups, the left-handers consistently have fewer non-smokers than dextrals. The amount smoked also significantly varies by handedness; data in the bottom row (Total) show that 68% of left-handers smoked 10 or more cigarettes daily compared with 49% of right-handers (p< .0005). Table 1 also indicates the same pattern within each of the four race-sex subgroups. Predictably a greater proportion of males than females smoked more cigarettes daily (p< .0005); and more whites tended to smoke 30 or more cigarettes daily than did blacks. Left-handed males had the greatest percentage of smokers (90%), as well as the greatest percentage smoking 10 or more cigarettes daily (78%). Table 1 also indicates that black femalesl stand out as the group with the fewest smokers, even among left-handers."(Harburg, E., Feldstein, A., Papsdorf, J. (1978) Handedness and smoking. Perceptual and Motor Skills 47: pp. 1172)

"The ethnographic record {e.g., A French Army Surgeon (1898/1972), a 30-year specialist in genitourinary diseases} makes reference to numerous anatomical distinctions which show a similar pattern of whites being between blacks and Orientals. These include the placement of female genitals (Orientals front and high; blacks back and low); angle and texture of erection (Orientals parallel to body and stiff, blacks at right angles to body and flexible); salient buttocks, breasts, and muscularity (Orientals least, blacks most); and size of genitalia (Orientals smallest, blacks largest). We averaged the ethnographic data on erect penis and found the means to approximate: Orientals, 4 to 5.5 in. in length and 1.25 in. in diameter; Caucasions, 5.5 to 6 in. in length and 1.5 in. in diameter; blacks, 6.25 to 8 in. in length and 2 in. in diameter. Women were proportionate to men, with Orientals having smaller vaginas and blacks larger ones, relative to Caucasians. Clitoral size differed in length: in European women, 1.2 in.; in African women, 2 in. variations were noted; in French West Indies, the size of the penis and vagina covaried with amount of black admixture; Arab men, who were often mixed with black, had larger penises than Europeans. Recent data show similar patterns. Measurements taken from living subjects as well as those at autopsy, show the size of testes is twofold lower in Asian men than Europeans (9 g vs 21 g), a difference too large to be accounted for entirely in terms of body size (Diamond, 1986; Short, 1984). Concomitantly, as mentioned, Asian women have lower ovulation rates than Caucasian women, as indexed by dizotic twin frequency, with the frequency per 1000 across several Asian populations being < 4, while for Caucasians it is 8, and for blacks 16 per 1000 (Bulmer, 1970; Diamond, 1986). Contrary to the general trend, Freeman (1934) observed that, at autopsy, American blacks had less heavy testes than American whites (13g vs 15g). Freeman (1934), however, did find that black women had heavier ovaries than white women. Subsequently Daniel, Fienstein, Howard-Peebles, and Baxley (1982) found no black-white difference in testicular volume among American adolescents, while Ajmani, Jain, and Saxena (1985) found larger scrotal circumference in Nigerians than Europeans (212.6 mm vs 195.1 mm or 8.37 in. vs 7.68 in.). A French Army Surgeon (1988/1972) also provided early observations that, in speed of sexual maturation, Orientals < whites< blacks. Several subsequent studies are confirmatory. In the United States, blacks are more precoscious than whites as indexed by age at menarche, first sexual experience, and first pregnancy (Malina, 1979). A national probability sample of American youth found that by age 12, 19% of black girls had reached the highest stages of breast and pubic hair development, compared to 5% of white girls (Harlan, Harlan, & Grillo, 1980), although the same survey found white and black boys to be similar (Harlan, Grillo, Coroni-Huntley, & Leaverton, 1979). Subsequently, Westney, Jenkins, Butts, and Williams (1984) found that 60% of 11-year-old black boys had reached the stage of acelerated penis growth in contrast to the white norm of 50% of 12 1/2-year-olds. This genital stage significantly predicted onset of sexual interest, with 2.2% of the black boys experiencing intercourse by age 11. While some surveys found that Oriental girls enter puberty as early as whites (Eveleth & Tanner, 1976), others suggest that in both physical development and onset of interest in sex, the Japanese, on the average, lag 1.5 to 2 years behind white Americans (Asayama, 1975). (Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal Research in Personality 21(4): pp. 536-7)

"As can be seen in Table 2, the results showed that African adolescents are more sexually active than Europeans, who are more sexually active than Asians." (Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal Research in Personality 21(4): pp. 535)

"The rate of premarital intercourse is matched by that following marriage. We inspected a section on cross-cultural intercourse frequency in a review by Ford and Beach (1951) and categorized the tribal peoples listed into three main groups. The Oceanic and Amerindian peoples tended to a lower per week average (1-4), than U.S. whites (2-4), than Africans (3-10). Recent surveys support the same conclusion. For married couples in their 20's, the average frequency per week of intercourse for the Japanese approximates 2 (Asayama, 1975), for American whites 4, and for American blacks, 5 (Fisher, 1980)." (Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal Research in Personality 21(4): pp. 535)

"Conjecturing as to physiological mechanisms, one hypothesis implicates testosterone and other sex hormones. Freeman (1934) found differences in the weight of the hypophysis (pituitary) with blacks having the heaviest (800 mg), whites being intermdiate (700 mg), and Orientals the lightest (600 mg). The pituitary is directly involved with the release of gonadotropins which stimulate the testicles and ovaries in their functions (the release of testosterone, estradiol, and progesterone on the one hand, and sperm and eggs on the other)." (Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal Research in Personality 21(4): pp. 546)

"Compared to whites the black respondents in this sample entered puberty at a later age, but did tend to leave home earlier." (Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal Research in Personality 21(4): pp. 539)

"While the monozygotic twinning rate is nearly constant at about 3 1/2 per 1000 in all groups, dizygotic twinning (the r-strategy) is greater among lower than upper social class women in both European and African samples (Golding, 1986; Nylander, 1981). Also, the rate per 1000 births among Mongoloids is <4; among Caucasoids, 8; and among Negroids, >16, with some African populations having rates as high as 57 per 1000 (Bulmer, 1970). The incidence of nonmonozygotic triplets and quadruplets shows comparable rank orders. Moreover, data from racially mixed matings suggest that the mother independently of the race of the father, as shown for Mongoloid-Caucasoid crossings in Hawaii, and Caucasoid-Negroid crosses in Brazil (Bulmer, 1970)." (Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal Research in Personality 21(4): pp. 534)

"Novel analyses of data from the Institute for Sex Research are also carried out, indicating that American blacks, compared to American whites, are more precocious and less constrained. Their parents were younger when they were born, had more children, and had an earlier mortality. Blacks left home earlier, experienced a variety of premarital and extramarital partners, had a greater frequency of marital intercourse, used fewer contraceptives, and had a greater incidence of pregnancy, at a faster rate. The men had larger penises, at a different angle of erection, and maintained intromission longer, while the women had shorter menstrual cycles, more periodicity of sexual intercourse, and a greater number of orgasms per act of coitus. Whites varied their sexual activity more, both with spouses and with protitutes, although blacks consorted with protitutes more frequently. Finally, blacks had a shorter duration of marriage and more permissive sexual attitudes." (Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal Research in Personality 21(4): pp. 529)

"The issue of whether populations differ in brain size remains controversial. Cranial capacities were calculated from external head measurements reported for a stratified random sample of 6,325 U.S. Army personnel measured in 1988. After adjusting for the effects of stature and weight, and then, sex, rank, or race, the cranial capacity of men averged 1,442 and women 1,332 cm3; that of officers averaged 1,393 and enlisted personnel 1375 cm3; and that of Mongoloids averaed 1,416. Caucasoids 1.380, and Negroids 1,359 cm3. (Rushton, J.P. (1992) Cranial capacity related to sex, rank, and race in a stratified random sample of 6325 US military personnel. Intelligence 16 (3-4): pp. 401)

"Caucasian men have, on average, a larger cranial capacity than do their Mongoloid counterparts, whereas Mongoloid women have a larger cranial capacity than do Caucasian women. Negroid men and women have smaller cranial capacities than do Mongoloid and Caucasoid men and women." (Rushton, J.P. (1992) Cranial capacity related to sex, rank, and race in a stratified random sample of 6325 US military personnel. Intelligence 16 (3-4): pp. 405)

"Thin men have higher testosterone levels than do heavier men (10). Because the white men in this study were, on average, 11 pounds lighter than black men despite similar mean heights, we might expect white to have somewhat higher testosterone levels. In fact, simultaneous adjustment for weight and age exagerated slightly the differences in testosterone levels between the two groups.....Although alcohol intake is known to decrease circulating testosterone (13) when measured in close proximity to ingestion, there is no evidence of any long-lasting effect (10). .... Prostate cancer is reportedly much less common (4,17) and testosterone levels are reportedly substantially lower (18) in Africanblacks compared to U.S. blacks. (Ross, R., Bernstein, L., Judd, H., Hanisch, R., Pike, M., and Henderson, B.E. (1986) Serum testosterone levels is healthy young black and white men. Journal National Cancer Institute 76: pp. 47)

"Blacks in the United States have the highest prostate cancer rate in the world and nearly twice that of whites in the United States. The 2:1 black-to-white ratio in prostate cancer rates is already apparent at age 45 years, the age at which the earliest prostate cancer cases occur. This finding suggests that the factor(s) responsible for the difference in rates occurs, or first occurs, early in life. Testosterone has been hypothesized to play a role in the etiology of prostate cancer, because testosterone and its metabolite, dihydrotestosterone, are the principal trophic hormones that regulate growth and function of epithelial prostate tissue. This report gives the results of assays of circulating steroid hormone levels in white and black college students in Los Angeles, CA. Mean testosterone levels in blacks were 19% higher than in whites, and free testosterone levels were 21% higher. Both these differences were statistically significant. Adjustment by analysis of covariance for time of sampling, age, weight, alcohol use, cigarette smoking, and use of prescription drugs somewhat reduced the differences. After these adjustments were made, blacks had a 15% higher testosterone level and a 13% higher free testosterone level. A 15% difference in circulating testosterone levels could readily explain a twofold difference in prostate cancer risk. ... For this study we solicited 50 white and 50 black volunteers at two Los Angeles area universities: the University of Southern California (USC) and California State University of Los Angeles (CSLA)" (Ross, R., Bernstein, L., Judd, H., Hanisch, R., Pike, M., and Henderson, B.E. (1986) Serum testosterone levels is healthy young black and white men. Journal National Cancer Institute 76: pp. 45)

"The groups with the earliest median age for menarche (first mentrual period) are the well-off in Istanbul (age 12.3), Singapore (12.4) and Hong Kong (12.5), and Afro-Americans (12.5). Those with the latest menarche are in New Guinea and East Africa (15.5 to 18.0)." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 275)

"The growth of Africans in Africa is limited in most populations by undernutrition and disease, especially in the first few years after birth, to which period special attention in given. Well-off groups of Africans (e.g. Yoruba in Nigeria belonging to the upper classes) grow in height and weight very much as do Europeans, and in the United States recent surveys have established that children of predominantly African descent are taller and heavier at all ages than children of European descent, even at somewhat lower economic levels. This is chiefly because the Afro-American children mature faster from birth onwards, alike in dental development, skeletal maturity, pubertal development (mean menarche age 12.5 years compared with 12.8 years) and percentage of adult height attained at successive ages. There is little reason to suppose that groups of Africans in Africa would not grow similarly if their environmental conditions were better." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 274)

"Asiatics, even those who are growing up under the best circumstances, are less tall at all ages than well-off Europeans and Africans. Chinese and Japanese mature as early or earlier than well-off Africans and considerably earlier than populations in Northwest Europe.....At puberty Asiatics have a different pattern of skeletal maturation from Europeans and Africans, increasing their rate of maturing more swiftly and reaching full skeletal maturity earlier." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 274)

"Chinese in Hong Kong have one of the earliest recorded medians (12.5 for well-off, 12.8 for middle class and 13.3 for poor) and Japanese are relatively early (12.9). New Zealand Maori are earlier (12.7) than New Zealand Europeans (13.0), both figures being derived from a full national survey (Fig. 167). Though Africans in Africa, even those apparently well-off, are relatively late (13.4, Uganda; 14.1, Nigeria), Afro-Americans are early, averaging 12.5 (Fig.167). People largely of European-African mixture in Cuba average 13.0 over the whole island, but about 12.6 in Havana. It seems likely, therefore, that in good environmental conditions Africans may be as early-maturing in this parameter as Asiatics and southern Europeans, and earlier than the peoples of Northern and Central Europe. Girls in the Near East have a relatively late menarche, with the exception of well-off girls in Istambul who at 12.3 have the earliest median of any population studied. Even the poor in Estanbul average 13.2 years. In India the well-off average about 12.8, and the poor up to 14.5. The people with the latest menarche are the Melanesians of New Guinea, having medians ranging from 15.5 to 18.4 years (Fig. 167). Menarche is delayed by chronic undernutrition. In the poor rural area of 'Appalachia' in the southern United Stated thirty undernourished Euro-American girls followed longitudinally had a mean menarcheal age of 14.4 years against 12.4 in the well-nourished controls (Dreizen, Spirakis & Stone, 1967). They were likewise delayed in skeletal maturation and shorter in height during childhood, though they reached the height of the controls at maturity. ... In the nineteenth century menarche occured on average around 15 years in England and in Norway and Finland at nearly 17 years (Tanner, 1966c). The trend shown in Fig. 168 (a) represents about 0.3 years per decade. There is some evidence that this trend is now stopping...." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 213-217)

"Afro-American girls have menarche some 0.3 years earlier than European-descended girls (12.5 compared to 12.8 years) and in both sexes dental and skeletal development is advanced in Afro-Americans (Garn et al., 1972a,b). Thus, part of their greater height is due to earlier maturation. Figs. 173 and 174 show the weight curves. Whereas Washington and London children are quite similar from 1 year until puberty, birth weights appear to be lower in African descendants when US samples adjusted for income, maternal age, parity and smoking and compared (Penchaszadeh et al., 1972). Hong Kong Chinese are lighter at every age. Thus they are lower in weight-for-height than London and Washington children, who are similar. In summary then, Afro-American children growing up under favorable conditions are a little taller and heavier than Europeans and Euro-Americans living in the same cities. This is partly or wholly because they are a little more advanced in maturity. Asiatics, on the other hand, under equally favourable circumstances are smaller despite being still further advanced in maturity." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 229)

"Thus, the human penis shows high species-specificity as an elaborated genital structure. Penis size also varies moderately across populations, being largest among African populations, smaller among European populations, and smallest among East Asian populations, but with substantial overlap (Rushton, 1987, 1988b, 1989b). Penises are highly age-specific, attaining their full resting size only after puberty, and are highly courtship-specific, attaining their full erect size only under sexually arousing conditions. Thus, penises show all the hallmarks of a morphological trait elaborated somehow through sexual selection." (Miller, Geoffrey F. (1994) Evolution of the human brain through runaway sexual selection: the mind as a protean courtship device. unpublished thesis. pp. 185)

"The rate of monozygotic twinning is very much the same throughout the world: about 3 twin births per 1000. The dizygotic twinning rate, however, varies considerably. Thus, some older data showed that in Japan there was approximately 1 dizygotic twin birth out of 165, whereas in the northern countries of Ireland and Scotland the rate was about three times as high. The rates in northern Europe are generally of this order, and those in southern Europe are lower (Bulmer 1970). The highest twinning rates so far observed occur in West Africa, particularly among the Yoruba, especially in the vicinity of Ibaden, where the rate is about 1 in 18 births. In young Yoruba women of high parity the rate of twinning may be nearly 1 in 10 births. It is no surprise that twin dolls are a characteristic feature of Yoruba art. In the United States, Blacks (most of West African descent) have higher twinning rates, and Orientals have lower twinning rates than Caucasians (Bulmer 1970).

"Buttock size also shows moderate population-specificity, being fairly small among East Asian populations and larger among European and African populations. Among the Kalahari bushwomen and the Hottentots, female buttock size is particularly exaggerated into a condition known as "steatopygia"; this condition bears no clear relation to any ecological requirement for fat storage." (Miller, Geoffrey F. (1994) Evolution of the human brain through runaway sexual selection: the mind as a protean courtship device. unpublished thesis. pp. 203)

"In this little book [A Short Course on Physical Anthropology] and in a later article Drennan [M.R.] employed the concept of neoteny to explain the strikingly large brains of the extinct Aftrican humans known as Boskop [Boskopoids] man, as well as many of the features of their presumed descenants, the Bushman of Khoi San of South Africa." (Montagu, Ashley (1989) Growing Young N.Y.: McGraw Hill pp. 240) [on page 263 he says they went extinct about 100,000 years ago]

"A useful paradigmatic case is provided by the emergence of bipedal locomotion, a species typical, centrally organized neuromotor action pattern shown by all normal adults --- indeed by all normal 2 year olds--- in our species. The mean age of attainment of one useful criterion, three steps taken without hands held, hovers around a year of age in many samples, usually falling between 11 and 14 months. Large samples studies is five European cities had means with 6 weeks of each other at the extremes. (Hindley et al., 1966) Precocity for infants in developing countries, especially Africa, has been frequently been claimed (Super, 1981; Werner, 1972, 1979). Some carefully designed and conducted studies, however, fail to show any difference, and one critical review of a large numbe of studies concluded that African infant precocity has not been demonstrated. (Konner, Melvin (1991) Universals of Behavioral Development in Relation to Brain Myelination in Brain Maturation and Cognitive Development: Comparative and Cross-cultural Perspectives (K.L. Gibson & A.C. Peterson, ed.) DeGruyter, N.Y. pp. 200)

"On the basis of recent studies of the incidence of the Duffy blood group gene Fya, which is absent in Africans but has a high frequency in Europeans, Reed (1969) has estimated that on average about one-fifth to one-quarter of the genes of persons currently regarded as Afro-Americans are of European origin." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 82)

"Even the rural Tutsi, a Nilo-Hamitic group of people who as adults are taller than Bantu or Sudanese (Fig. 75) are usually shorter than the urban Bantu during childhood, and achieve their adult height by way of a longer growing period. At 18 years Tutsi boys are still 12 cm below their adult mean compared with 1.4 cm for Mozambique Bantu and 2.1 cm for Tanzania Bantu." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 88)

"Most children of African origin lie well within the European range until the age of 6 months. At that age African village children fall off in rate; the prividged urban children, on the other hand, remain at the European level." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 104)

"In calf circumference all African groups are lower than the European range, as might be expected, since the slender African calf, like the longer legs, is believed to be a genetic characteristic."(Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 111)

"The populations themselves show no striking departures from the overall regression, however. By 16 years (Fig.131) boys' and girls' plots are clearly separated. This occured also in European populations, but not in African or Asiatic ones." [less dimorphic?] (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 169)

"At 15 years, when British girls have nearly attained adult height, Bundi girls have reached only 91.5% adult height. At 17 years a similar situation holds for boys. Thus Bundi youth, in a similar way to Hutu and Tutsi youth of East Africa (Chapter 4), have considerably more growth ahead of them at 15 to 17 years than British adolescents." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 183)

"Aborigines have much the longest legs for trunk length; their relative sitting height indices at every age are among the lowest in the world, being even less than those of most African groups (Appendix Table 49). The Nilotes of East Africa may be lower, but we do not have any sitting height data from them to use for comparison. As in Africans, the distinctive shape of the Aborigines is already present at an early age." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 194)

"A number of investigators have studied the effects of malnutrition on tooth eruption (Graham & Morales, 1963; Cifuentes & Alvarado, 1973; Neill et al., 1973; Truswell & Hansen, 1973). Infants who are small-for-dates have a delayed eruption. Eruption is delayed also in triplets and higher order multiple births. Possibly infants with severe protein-calorie malnutrition are delayed, but if so, the effect is considerably less on dentition than it is on weight, height or skeletal development (Meredith, 1973; Robinow, 1973). Hong Kong Chinese infants (Billewicz, Thomson, Baber & Field, 1973) do not differ significantly in deciduous eruption times from Newcastle British (Billewicz et al., 1973) or New Guineans (Bailey, 1964b)(Fig. 163; Appendix Table 107). Generally, Australian Aborigines, Bengalis, Hindus, Nigerian villagers and Gambians (not shown in Fig. 163) have slightly delayed eruption. The two Nigerian samples are interesting in showing environmental contrasts (Enwonwu, 1973). Both groups are Yoruba, but one comes from the group of Ibadan privileged that we have examined before in other parameters of growth, and the second in derived from the rural villages of Osgere and classed as underprivileged. The well-off group has by far the most advanced eruption, not only compared with the villagers, but with all the groups shown in Fig. 164. These Nigerian data throw some doubt on the wisdom of using number of erupted primary teeth as a guide to chronological age in tribal groups where age is not known. This has been advocated by various authors (Bailey, 1964b, Brook & Barker, 1973; Malcolmm 1973; Billewicz, 1973) on the grounds that it is less affected by sex, race and poor nutrition than any other indicator." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 207-8)

"Whereas there are no clear differences between ethnic groups in the age of eruption of deciduous teeth, there are marked ones in the permanent dentition (Figs. 165 and 166; Appendix Table 109). Most investigators agree that the peoples of New Guinea, together with Africans in Africa and the United States, are the most advanced." (Eveleth, P.B. & Tanner, J.M. (1976) Worldwide Variation in Human Growth: Cambridge Univ. Press, London p. 210)


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