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Showing papers in "Annals of Human Biology in 1983"


Journal ArticleDOI
TL;DR: A two-part hypothesis for the apparent maturity delay in athletes is suggested which combines biological selective factors (i.e., physique and skill) and social factors and family size influences the timing of menarche.
Abstract: The determinants of the timing of menarche are many, and it is difficult to isolate a single factor which may delay or accelerate this maturational event. Menarche, on average, occurs later in athletes, including ballet dancers, than in the general population. With few exceptions, the data are consistent across several countries. Swimmers are an exception to the tendency towards later menarche in athletes. In all samples of swimmers surveyed but one, menarche tends to approximate the average for the general population. The menarcheal data are consistent with other indices of biological maturity status, i.e., skeletal age and secondary sex character development. The data dealing with the effects of intensive physical training on menarche are reviewed and given the number of factors involved, it is difficult to implicate training as a factor which specifically delays menarche. A two-part hypothesis for the apparent maturity delay in athletes is thus suggested. The hypothesis combines biological selective factors (i.e., physique and skill) and social factors. Family size and composition, however, must receive more consideration. Family size influences the timing of menarche and such a trend is apparent in data for several groups of athletes.

224 citations


Journal ArticleDOI
TL;DR: The age at menopause in Upper Chumik is accelerated relative to that reported for Western industrial populations; however, these data do not permit drawing conclusions about the reasons underlying the acceleration.
Abstract: Women in a Tibetan speaking population living at 3250-3560 m in Upper Chumik, Nepal, have median ages at menopause and menarche of 46.8 and 16.2 years, respectively, assessed by the status quo technique. Recalled ages at menopause and menarche yield similar results and suggest a long-term existence of a pattern of relatively accelerated age at menopause and delayed age at menarche. Variation in the length of the calculated biological reproductive span in this sample is more strongly associated with recalled age at menopause than recalled age at menarche. The age at menopause in Upper Chumik is accelerated relative to that reported for Western industrial populations; however, these data do not permit drawing conclusions about the reasons underlying the acceleration.

79 citations


Journal ArticleDOI
Grace Wyshak1
TL;DR: In an epidemiological survey of the reproductive history of a large group of United States women who had given birth to at least one child, there was a secular trend in age at menarche between thoseBorn around 1920 and those born around 1940-45.
Abstract: In an epidemiological survey of the reproductive history of a large group of United States women who had given birth to at least one child, there was a secular trend in age at menarche between those born around 1920 and those born around 1940-45. The trend was linear and the increment 3.2 months (+/- 0.36) per decade. The women were White, well nourished, middle-class and resided in all parts of the United States.

75 citations


Journal ArticleDOI
TL;DR: Evidence is presented to show that castes living together in the same region had so organized their pattern of resource use as to avoid excessive intercaste competition for limiting resources, which favoured the cultural evolution of traditions ensuring sustainable use of natural resources.
Abstract: Indian society is an agglomeration of several thousand endogamous groups or castes each with a restricted geographical range and a hereditarily determine mode of subsistence. These reproductively isolated castes may be compared to biological species, and the society thought of as a biological community with each caste having its specific ecological niche. In this paper we examine the ecological-niche relationships of castes which are directly dependent on natural resources. Evidence is presented to show that castes living together in the same region had so organized their pattern of resource use as to avoid excessive intercaste competition for limiting resources. Furthermore, territorial division of the total range of the caste regulated intra-caste competition. Hence, a particular plant or animal resource in a given locality was used almost exclusively by a given lineage within a caste generation after generation. This favoured the cultural evolution of traditions ensuring sustainable use of natural resources. This must have contributed significantly to the stability of Indian caste society over several thousand years. The collapse of the base of natural resources and increasing monetarization of the economy has, however, destroyed the earlier complementarity between the different castes and led to increasing conflicts between them in recent years.

64 citations


Journal ArticleDOI
TL;DR: Weight measurements at frequent intervals, from age six to adulthood, of 248 contemporary middle-class American girls were fitted to a mathematical model to examine weight and weight velocity at specified ages, the characteristics of the weight growth spurt and the relation of this spurt to menarche.
Abstract: Height measurements at frequent intervals, from age six to adulthood, of 338 middle-class American girls are used to examine contemporary height and height velocity at specified ages, the characteristics of the adolescent growth spurt and its relation to menarche. These data, analysed by fitting to a mathematical model (Preece and Baines 1978), are presented as tables of means and standard deviations, percentiles and correlations. There is no evidence of a trend towards increased or accelerated growth in height; in the United States and Western Europe, girls have been the same height at specified ages, and have grown at the same rate, for the past 45 years, at least. Examination of the data plots and the growth statistics of all 338 girls revealed a group of 67 girls (designated E) who are different from the remaining 271 girls (designated S). Plots of the E girls show no discernible growth spurt. Compared with the S girls, they are significantly taller at specified ages; velocities are greater at ages 6 and 9 but less at age 12. During the growth spurt, and at menarche, they are taller but not older. Their adult height is greater and is reached later. Their velocity at takeoff is greater but, at peak, smaller; spurt intensity is much lower. Their adolescent growth spurt contributes less to adult height. For all 338 girls (the E as well as the S subgroup), adult height is correlated only with height during the growth spurt and is virtually independent of spurt timing, whereas menarche is strongly correlated with spurt timing and very little with height. Additional indications that menarche is unrelated to size are that E girls at menarche are significantly taller but not older than the S girls, and that 19 prematurely-born girls at menarche are shorter than girls born at full term but the same age.

62 citations


Journal ArticleDOI
TL;DR: When lean body weight was predicted by multiple regression, leg lean area was the best predictor of any anatomical cross-section and abdomen circumference plus one skinfold provided excellent prediction of total abdomen fat area.
Abstract: SummaryComputed tomography (CT) scanning was evaluated for its potential application to body-composition research. Three cross-sections (upper leg, abdomen, chest including upper arms) were scanned in 41 healthy men (mean age 57·6 years). Subcutaneous fat thicknesses measured at specific sites on the CT scans were correlated with the total area of fat from the same scans. For the chest and leg cross-sections, correlations were highly significant. Subcutaneous fat thicknesses at the abdomen were relatively poorer correlates of total abdomen fat area, because they were unrelated to intra-abdominal fat. Correlation analyses were performed between fat areas of each cross-section and total fat weight (by 40K counting), and the abdomen yielded the highest correlations. Multiple regression was used to predict abdomen fat area from external anthropometry, and abdomen circumference plus one skinfold provided excellent prediction of total abdomen fat area (R2 = 0·79). Subcutaneous or intra-abdominal fat areas separ...

61 citations


Journal ArticleDOI
TL;DR: Intra-pair height and weight differences and differences in their growth velocities indicate that MZ twins are more concordant than DZ twins throughout the adolescent growth period.
Abstract: SummaryForty-eight pairs of MZ and like-sex DZ twins of Panjabi parentage were studied longitudinally for such pubertal changes as growth of genitalia, pubic, axillary and facial hair, change of voice and ejaculation of semen in boys, and growth of pubic and axillary hair, breast development and onset of menarche in girls, besides growth in height and weight. Mean intrapair age differences are small and intra-pair correlations for age at different secondary sexual developments are higher in MZ twins than in DZ twins in both sexes. Mean intra-pair differences and intra-pair correlations for the time taken to pass from first stage to the final stage of development also present a similar picture. Intra-pair height and weight differences and differences in their growth velocities also indicate that MZ twins are more concordant than DZ twins throughout the adolescent growth period. These findings indicate a strong genetic component in regulating the pubertal changes as well as in the growth of height and weigh...

54 citations


Journal ArticleDOI
TL;DR: Test of the hypothesis that in modern stratified societies upward and downward social mobility is selective with respect to body height found that among the 116 male pairs in which the sibs differed in both education and stature, the proportion of pairs inWhich the taller sib was the better educated (BE) was significantly higher than the proportion that the shorter siber was the less well educated (LE) of the two.
Abstract: SummaryStature and education in 214 pairs of adult brothers and 188 pairs of adult sisters were analysed in order to test the hypothesis that in modern stratified societies upward and downward social mobility is selective with respect to body height. Among the 116 male pairs in which the sibs differed in both education and stature, the proportion of pairs in which the taller sib was the better educated (BE) was significantly higher than the proportion of pairs in which the taller sib was the less well educated (LE) of the two. Mean intra-pair difference in stature between the BE and LE brothers was 1·26 cm, and significantly different from zero. In female pairs similar tendencies were noted but deviations from the null hypothesis were not significant. Implications of these findings are discussed.

53 citations


Journal ArticleDOI
TL;DR: The increasing fit of stature distribution to the Normal distribution agrees with the hypothesis of an increasing expression of the genetic endowment in consequence of a progressive improvement in living conditions.
Abstract: The secular trend of stature in Italy from 1874 to 1960 has been examined using military records concerning nearly complete samples of males born in Italy in given years. The national mean value increased by nine cm (about one cm/decade) and the averages of the different Italian regions tend progressively to aggregate towards higher values (the north) and lower ones (the south). The rate of increase of stature was more or less constant up to subjects born in 1945, but in the period 1945-55 a very steep increase was observed. In more recent times, a clear slowing down has taken place both at national and regional level. The following moments around the mean were investigated: (1) variance--the national value has remained more or less constant and regional values pass from very diverse figures to very similar ones; (2) skewness--the initially negative national value has become slightly positive; in the regions, from very diverse negative values a close aggregation around zero is recently attained; (3) kurtosis--initial national hyperkurtosis has reduced to values typical of the Normal distribution; the same is true for regional figures which, moreover, have become closely aggregated. The increasing fit of stature distribution to the Normal distribution agrees with the hypothesis of an increasing expression of the genetic endowment in consequence of a progressive improvement in living conditions.

52 citations


Journal ArticleDOI
TL;DR: It is inferred that differences in height between occupational and family-size groups resulted more from differences in leg than in trunk length, and that heights significantly lower than average were found only among subjects with fathers in unskilled manual occupations and with large families.
Abstract: White Newcastle upon Tyne schoolchildren born in 1962 were examined at approximately half-yearly intervals from 9 to 17 years of age. During the last year of compulsory education losses to follow-up became selective with respect to socio-economic background, and the results reported here are restricted to 564 boys and 669 girls seen regularly between the ages of 10 and 15 years at least. Newcastle adolescents were slightly shorter and lighter than the London children on whom Tanner's British Standards were based. The longitudinal pattern of skinfold changes in boys was different from that observed in girls. Differences in height attained between occupational groups were well established by the age of five years, and the same was true of differences between family-size groups for children with fathers in manual occupations. It is inferred that differences in height between occupational and family-size groups resulted more from differences in leg than in trunk length. At age 15, the correlations of height attained with maternal height were 0.42 and 0.43, and with birthweight 0.25 and 0.28, for boys and girls respectively. Adjustment, by regression, of heights attained for birthweight, age at peak height velocity and maternal height diminished differences between occupational and family-size groups. After such adjustment, heights significantly lower than average were found only among subjects with fathers in unskilled manual occupations and with large families. Among subjects with fathers in manual occupations, subscapular and triceps skinfolds and arm circumference decreased significantly with increasing family size.

46 citations


Journal ArticleDOI
TL;DR: Conditional standards for length and weight in preschool children are presented, which assess a child's length or weight taking into account previous measurements and/or a current measurement of a second anthropometric variable.
Abstract: The appropriateness of a preschool child's size at a particular age is usually assessed by comparing the child's measurement against growth charts. When the child has measurements at more than one age, the child's percentile status at one age is sometimes compared with the percentile status at a subsequent age, with the purpose of assessing the child's pattern over time or growth rate. This second use of growth charts is not entirely appropriate, for it assumes a high degree of 'tracking' in the population. Healthy children frequently cross percentile lines, the amount of shifting depending upon the age range under consideration, the child's sex, and whether the measurements are length or weight. Thus the correct evaluation of percentile-level changes over time is difficult. We present here conditional standards for length and weight in preschool children, which assess a child's length or weight taking into account previous measurements and/or a current measurement of a second anthropometric variable. The approach can be very flexible as regards ages of measurement, although complete flexibility requires use of a computer. In addition to its clinical application, this approach can be used to predict the future size of a child and may be valuable as an analytic tool in research situations in which control populations are not feasible.

Journal ArticleDOI
TL;DR: The risk of having poor gynaecological health (high GYNDEX) is greatly increased for women experiencing both dysmenorrhoea and irregularity in the first few years postmenarche.
Abstract: SummaryIn a sample of 54 women who have participated in a longitudinal study since birth there is a significant relationship between adolescent menstrual characteristics and gynaecological health as measured by GYNDEX (Gardner 1982) in the second and third decades postmenarche. The menstrual characteristics were recorded in health histories taken in the 1940s as part of a yearly evaluation of growth, development and health status. Using stepwise multiple regression analysis, the measures of regularity and dysmenorrhoea in adolescence explain 46% of the variation in GYNDEX from 11 to 20 years postmenarche (P<0·001). These variables are still significant predictors 21 to 30 years postmenarche, explaining 26% of the variance (P<0·005). The risk of having poor gynaecological health (high GYNDEX) is greatly increased for women experiencing both dysmenorrhoea and irregularity in the first few years postmenarche.

Journal ArticleDOI
TL;DR: The findings that spouses do not covary significantly in fatness, while biological relatives of traditional nuclear families exhibit a significant degree of resemblance even after statistical control over daily energy intake, daily energy expenditure and socioeconomic status provide evidence supporting the hypothesis that there is a substantial genetic effect in human fatness.
Abstract: Family resemblance in fatness has been studied in 481 individuals from 114 families of French descent living in the greater Quebec city area. Subjects were measured for the following fatness indicators: triceps, biceps, subscapular, suprailiac, abdominal and medial calf skinfolds. The sum of these six skinfolds as well as a prediction of percent body fat (Durnin and Rahaman 1967) were also considered. Data were standardized for appropriate age and sex classes yielding SS scores. The influence of relevant lifestyle variables (energy intake, energy expenditure and socioeconomic status) were statistically removed from SS yeilding residual scores (RS) that were then submitted to familial analyses. Analyses of variance indicate that there is a larger between family variation than within (P less than or equal to 0.01) for SS when considering either the whole nuclear family or sibships; in these instances, the intra-class correlation ranges from 0.15 to 0.26. There was, however, no significant resemblance among spouses for the SS fatness indicators. Similar values were essentially found for RS fatness indicators. Furthermore, husband-wife inter-class correlations were not significant with the exception of subscapular and calf skinfold RS. Covariations between biological relatives are however significant (0.16 less than or equal to r less than or equal to 0.24, P less than or equal to 0.01) for SS and remain essentially unchanged after statistical control over the lifestyle variables (0.16 less than or equal to r less than or equal to 0.40, P less than or equal to 0.01). The findings that spouses do not covary significantly in fatness, while biological relatives of traditional nuclear families exhibit a significant degree of resemblance even after statistical control over daily energy intake, daily energy expenditure and socioeconomic status provide evidence supporting the hypothesis that there is a substantial genetic effect in human fatness.

Journal ArticleDOI
TL;DR: Well-off Sudanese girls in Khartoum have one of the earliest recorded means of all African populations studied and it seems likely that with improvement of health care and family planning, SudaneseGirls would be at least as early-maturing as girls in Northern and Central Europe.
Abstract: Data on age at menarche have been collected among 1372 Sudanese girls attending state schools within the capital, Khartoum, and representing three different socioeconomic groups. The mean ages, estimated by probits, were 13.35 +/- 0.14 for the well-off girls; 13.85 +/- 0.15 for the middle class and 14.06 +/- 0.18 years for the poor girls. The results were compared with data reported from other African and other Arabic-speaking countries. Well-off Sudanese girls in Khartoum have one of the earliest recorded means of all African populations studied. It seems likely that with improvement of health care and family planning, Sudanese girls would be at least as early-maturing as girls in Northern and Central Europe.

Journal ArticleDOI
Grace Wyshak1
TL;DR: Among Catholic women, who were unlikely to have had induced abortions at the time of the study, the differences by menarcheal age were greater than among non-Catholic women.
Abstract: We have examined the relation between age at menarche and unsuccessful pregnancy outcome among women under 40 years of age. Women with early menarche (under 12) and late menarche (14 or older) had a greater number of unsuccessful pregnancy outcomes than did women of intermediate age at menarche (12 or 13 years). The differences in means adjusted by covariance analysis for age, total number of pregnancies, age at first live birth and socio-economic status were statistically significant. Among Catholic women, who were unlikely to have had induced abortions at the time of the study, the differences by menarcheal age were greater than among non-Catholic women. These findings support those of Liestol (1980) who recently reported a possible causal connection between menarcheal age and spontaneous abortion.

Journal ArticleDOI
TL;DR: A mid-childhood growth spurt in height was found in 17 of 67 boys and in 0 of 67 girls followed from age two years to adulthood, and was detected analytically from variable knot cubic splines fitted to the longitudinal height data.
Abstract: SummaryA mid-childhood growth spurt in height was found in 17 of 67 boys and in 0 of 67 girls followed from age two years to adulthood. The growth spurt was detected analytically from variable knot cubic splines which were fitted to the longitudinal height data of each child.

Journal ArticleDOI
TL;DR: Curvilinear associations may be interpreted in terms of natural selection, and suggest that stature and sitting height may be undergoing stabilizing selection in this population of Papua New Guinea.
Abstract: SummaryAssociations between anthropometric variation and reproductive performance have important ecological and evolutionary implications. Bivariate associations between measures of reproductive performance (live births and offspring still living at the time of interview) and 24 anthropometric variables were examined in 150 females, aged 21–44 years, from the Eastern Highlands district of Papua New Guinea. Where significant linear or curvilinear associations with age existed, the reproductive and anthropometric variables were age-corrected. Linear, quadratic and cubic regressions were computed for each bivariate regression of age-corrected reproductive variable on age-corrected anthropometric trait. Positive linear regressions were found in the cases of body weight, triceps skinfold and head breadth. Positive cubic regressions were found in the cases of upper arm circumference, calf circumference, bicondylar femur and wrist breadth. It is suggested that these associations may reflect important ecological ...

Journal ArticleDOI
TL;DR: Longitudinal observations of boys investigated indicate that the increment from 18 to 27 years is strongly dependent on skeletal maturation and even on such a distant event as age at peak height velocity.
Abstract: Among 221 boys investigated, only 54% had the same (+/- 1 cm) body height at age 27 years as they had at age 19. Longitudinal observations of those boys indicate that the increment from 18 to 27 years is strongly dependent on skeletal maturation and even on such a distant event as age at peak height velocity. Average increment in stature was 2.13 cm, and the maximum increment was 7 cm. Late-maturing individuals are largely responsible for the differences in average stature observed in cross-sectional studies in the third decade of life.

Journal ArticleDOI
TL;DR: A study of lung function in 203 twin pairs aged 18-34 years living in Sydney detected significant genetic variation in females and males and the Pi polymorphism accounted for approximately 9% of the total variance in female lung function.
Abstract: SummaryA study of lung function in 203 twin pairs aged 18–34 years living in Sydney detected significant genetic variation in females and males. There was no evidence of family environmental effects in either sex and most of the repeatable variation in females was heritable. However, there was evidence for systematic environmental differences between males affecting lung function so that the heritability was lower in males (about 0·6) than females (about 0·8). An effect of smoking on lung function was detected but accounted for less than 3% of the variance. Lung function in females was greater in the M subtype heterozygotes at the Pi locus than in the M subtype homozygotes or in other Pi phenotypes with low α1-antitrypsin activity. The Pi polymorphism accounted for approximately 9% of the total variance in female lung function. No effect of the Pi locus was found in males.

Journal ArticleDOI
TL;DR: The Jenss curve is a non-linear regression model which describes quite well the longitudinal length or weight measurements of an individual child from three months to six years, and can be used to evaluate the success of other models.
Abstract: SummaryThe Jenss curve is a non-linear regression model which describes quite well the longitudinal length or weight measurements of an individual child from three months to six years. It is contrasted with modelling growth by longitudinal principal components analysis, an approach developed by Kent which is not restricted to any particular curve type or age range, and which can be thought of as providing the best fit among linear models having k parameters. Thus, in addition to being a model itself, it can be used to evaluate the success of other models. It is shown how this method differs from classical principal components. Data from Longitudinal Studies of Child Health and Development are used to explore these issues.

Journal ArticleDOI
TL;DR: A much higher spouse correlation in height than shown by earlier studies, a smaller heritability, and only a small effect of common-sib environment or genetic dominance deviations are obtained.
Abstract: Although height is widely cited as the classic polygenic trait, there have been few large-scale studies of its inheritance since that of Pearson and Lee 80 years ago (Pearson and Lee 1903). Values of heritability derived in many standard genetics texts are based on those data. The data of Rissanen and Nikkila (1977) on 2869 individuals in 392 three-generation families provide an opportunity to make comparisons in a contemporary European population. We examine here height differences between regions, sexes and generations, and consider the form of the population distribution. Analysing the data within the classic polygenic framework we obtain a much higher spouse correlation in height than shown by earlier studies, a smaller heritability, and only a small effect of common-sib environment or genetic dominance deviations.

Journal ArticleDOI
TL;DR: The genetic relationship of the Aran Islands to the rest of Ireland and England appears to be due to English admixture following the garrisoning of soldiers several centuries ago, and the genetic position of the midlands is more complex, but suggests the effects of early Viking inhabitation.
Abstract: Population structure and history may be studied on a local or a regional level. This paper examines the regional population structure of the Republic of Ireland and Northern Ireland with respect to population history and demographic processes. Blood-group and anthropometric data obtained from the literature are analysed. The blood-group data consist of ABO and Rhesus gene frequencies for 32 counties and the Aran Islands. Anthropometric data consist of summary statistics for 15 variables collected from 19 regions. The degree and pattern of population differentiation is assessed using new methods of population-structure analysis. Both blood group and anthropometric analyses show a west-east division of populations corresponding to the known history of inhabitation of Ireland, where successive waves of immigrants pushed earlier populations further west. In both analyses there were two deviations to this basic pattern: the Aran Islands and the midlands. In both cases, alternative historical explanations are examined. The genetic relationship of the Aran Islands to the rest of Ireland and England appears to be due to English admixture following the garrisoning of soldiers several centuries ago. The genetic position of the midlands is more complex, but suggests the effects of early Viking inhabitation. These findings are related to studies of the local, rather than regional, population structure of Ireland.

Journal ArticleDOI
TL;DR: Familial correlation coefficients were calculated for recumbent length or stature measured serially on participants in the Fels Longitudinal Growth Study and for short-term serial or cross-sectional measurements on relatives of participants.
Abstract: SummaryFamilial correlation coefficients were calculated for recumbent length or stature measured serially on participants in the Fels Longitudinal Growth Study and for short-term serial or cross-sectional measurements on relatives of participants. Pairs of relatives are compared at the same chronological ages from 1 to 18 years in 1-year increments and again in adulthood. First-degree relatives are more similar than second- or third-degree relatives at all ages. Sibling correlations are consistently higher than parent-offspring correlations, except after age 15, when they become very similar. For the most part, these results agree with those of cross-sectional studies finding higher sibling than parent-offspring correlations. Familial correlations tend to decrease during adolescence, perhaps due to differences among relatives in timing of growth spurts. Trends observed in bivariate plots of correlations over age are confirmed by multivariate analysis of correlations for different types of relatives at di...

Journal ArticleDOI
TL;DR: Overall genetic differentiation (HT) in Northern Athapaskans was greater than in the Mexicans, presumably because of high, though nonquantifiable European admixture in some of the tribes.
Abstract: Phenotypes and gene frequencies of genes at the ABO, Rhesus, MNSs, Diego, Duffy, Kell, Kp, Kidd and P blood group systems are presented for three villages of Dogrib Indians. This population resides between Great Slave and Great Bear Lakes in the Northwest Territories of Canada. Until recently they pursued an exclusively hunting-gathering-fishing lifestyle in the subarctic forest. Maximum European admixture in the Dogrib is 8.7%. Nei's coefficient of gene diversity, GST is 0.0121. Blood group data from other Athapaskan-speaking Indians were also examined. GST for Kutchin villages is approximately 1.1%. GST obtained over five tribes of Northern Athapaskans is 0.0264, a figure slightly lower than that found in comparable groups of Mexican Indians. Overall genetic differentiation (HT) in Northern Athapaskans was greater than in the Mexicans, presumably because of high, though nonquantifiable European admixture in some of the tribes. The bulk of the genetic variability in Athapaskans exists within tribes, and then within villages of the same tribe. Genetic distance analysis with Nei's standard distance D shows that Dogrib and Kutchin Indians are very close. Geographic proximity has no significant influence on inter-tribal gene flow, but is significantly associated with intra-tribal gene flow.

Journal ArticleDOI
TL;DR: Recollected age data when compared to previous data from the Greek population show a decrease of 0.46 years/decade from 1935 to 1964 and no appreciable change from 1964 to 1979, which may indicate that the trend in menarcheal age in Athens is levelling off.
Abstract: The age at the different stages of pubertal development, including menarche, was assessed by the status quo method in 1366 middle-class girls living in Athens. The initial pubertal event in the average Athenian girl was the appearance of pubic hair along the labiae (P10:8.85, P50:10.47), followed shortly by breast budding (P10:9.39, P50:10.62), and later on by axillary hair growth (P10:10.55, P50:11.63). The age at menarche was 12.58 +/- 0.07 years. It seems tht Athenian girls of 1979 have one of the earliest ages of menarche reported. Recollected age data on menarche when compared to previous data from the Greek population show a decrease of 0.46 years/decade from 1935 to 1964 and no appreciable change from 1964 to 1979. Although these data are not absolutely comparable from the methodological point of view, they may indicate that the trend in menarcheal age in Athens is levelling off.

Journal ArticleDOI
TL;DR: The study shows that the high rate of DZ twinning in Blacks is associated with maternal race and not paternal race, and further support the importance of maternal determinants of dizygotic twinsning in humans.
Abstract: SummaryIn the USA, Blacks have been shown to have a higher incidence of DZ twinning than Whites. We studied maternal and paternal race determinants of the rates of like-sex and unlike-sex twinning using US live-birth certificate data for 1973–78. After adjustment was made for father's race, Black mothers had a higher rate of unlike-sex twinning than White mothers (odds ratio, OR = 1·74, P<10−8). This maternal race effect persisted after further adjustments were made for maternal age, parity, education, and marital status and did not apply to the rates of like-sex twinning (OR = 1·06). On the other hand, after adjustment was made for mother's race, Black fathers did not have higher rates of unlike-sex (OR = 0·93) or like-sex (OR = 1·11) twinning than White fathers. The study shows that the high rate of DZ twinning in Blacks is associated with maternal race and not paternal race. The data further support the importance of maternal determinants of dizygotic twinning in humans.

Journal ArticleDOI
TL;DR: Pedigree and vital statistics data from the population of Sanday, Orkney Islands, Scotland, were used to assess temporal changes in population structure and observed secular trends illustrate the potential for change inpopulation structure characteristic of isolate breakdown.
Abstract: SummaryPedigree and vital statistics data from the population of Sanday, Orkney Islands, Scotland, were used to assess temporal changes in population structure. Secular trends in patterns of mate choice were analysed for three separate birth cohorts of spouses: 1855–1884, 1885–1924 and 1925–1964. The degree to which mating was random or assortative with respect to both genealogical and geographic distance was determined by comparing average characteristics of all potential mates of married males with those of actual wives. We integrated this procedure, originally developed by Dyke (1971), into a three-fold investigation of population structure: (1) comparison of random and non-random components of relatedness as measured from pedigree data; (2) an analysis of marital distance distributions for actual and potential mates of married males; and (3) the relationship between genealogical relatedness and geographic distance. As population size decreased from 1881 to the present, total kinship and spatial distan...

Journal ArticleDOI
TL;DR: The children were taller and heavier than Chinese children in Hong Kong, but height-forage, when expressed as a percentage of the UK median value, declined after two years of age and the pattern of growth of triceps skinfold did not conform to the UK standards.
Abstract: SummaryHeight, weight and triceps skinfold thickness of children aged 5 years and under were measured in a semi-longitudinal study of 50 Chinese families in London. Heights and weights of their mothers were also measured once.The children were taller and heavier than Chinese children in Hong Kong, but height-forage, when expressed as a percentage of the UK median value, declined after two years of age. The pattern of growth of triceps skinfold did not conform to the UK standards.

Journal ArticleDOI
TL;DR: It is concluded that genetic similarity between Jews is higher than between Gentiles and the heterogeneity and relative proportion of diversity were less between Jewish populations than between non-Jewish ones.
Abstract: Genetic diversity and F statistics analysis, using 9 and 5 blood group loci, respectively, were carried out on 16 Jewish populations from 5 geographic regions: East Europe, Central Europe, South Europe, Middle East and North Africa. The proportion of total diversity found within populations was 98.9% while that between populations, within geographic groups and between groups altogether was only 1.1%. The average heterozygosity between geographic groups ranged from 0.3867 to 0.4150. There were no significant differences between geographic groups of populations in heterozygosity or in its variance. Average estimates of inbreeding were as follows: Fis = 0.0419, Fst = 0.0084 and Fit = 0.0498. Because the heterogeneity and relative proportion of diversity were less between Jewish populations than between non-Jewish ones, we conclude that genetic similarity between Jews is higher than between Gentiles. The findings are in agreement with our previously obtained calculations of genetic distances (Kobyliansky, Micle, Goldschmidt-Nathan, Arensburg and Nathan 1982).

Journal ArticleDOI
TL;DR: Medical observations on 3385 Danish women, from the 1840s, indicate that at that time the average age at menarche was 16 years and 3 months for Denmark as a whole, which has decreased since then, with an average rate of 2 1/2 months per decade.
Abstract: SummaryMedical observations on 3385 Danish women, from the 1840s, indicate that at that time the average age at menarche was 16 years and 3 months for Denmark as a whole. Since then, age at menarche has decreased, with an average rate of a little over 2½ months per decade.