Human Biology

Published by Wayne State University Press
Online ISSN: 1534-6617
Print ISSN: 0018-7143
We found a novel polymorphic short tandem repeat (FUT2/01), 3.8 kb downstream of the coding region of FUT2. Seventeen length and 33 sequence variants were identified in 300 individuals representing three major human populations. Africans (Xhosa) and Europeans were characterized by high microvariation, and Japanese were characterized by a simple repeat structure. All exhibited high haplotype diversity.
The relations between ABO and Rhesus D blood groups and serum cholesterol, triglycerides and phospholipids were studied in blood samples obtained from 666 young Greek subjects (503 military conscripts and 163 high school girls or student nurses). Rh-negative subjects had higher serum cholesterol levels than those found in the Rh-positives. No difference was observed among the ABO groups and between the Rhesus groups as regards the distribution of triglyeride and phospholipid levels. Furthermore in this series, where cholesterol levels were generally low, no relationship was evident between ABO groups and serum cholesterol.
The aim of this study is to individualize potential differences between two cranial regions used to differentiate human populations. We compared the neurocranium and the facial skeleton using skulls from the Great Hungarian Plain. The skulls date to the 1st-11th centuries, a long space of time that encompasses seven archaeological periods. We analyzed six neurocranial and seven facial measurements. The reduction of the number of variables was carried out using principal components analysis. Linear mixed-effects models were fitted to the principal components of each archaeological period, and then the models were compared using multiple pairwise tests. The neurocranium showed significant differences in seven cases between nonsubsequent periods and in one case, between two subsequent populations. For the facial skeleton, no significant results were found. Our results, which are also compared to previous craniofacial heritability estimates, suggest that the neurocranium is a more conservative region and that population differences can be pointed out better in the neurocranium than in the facial skeleton.
Size (stature and body weight), shape (ponderal index and relative sitting height) and body composition (logΣ skinfolds and arm muscle and bone areas) were studied in 133 male and 120 female children from the Isle of Lewis. Demographic data were collected from their parents. There were significant differences in the regional distribution within the island of many of the demographic variables. In general, children from Urban Stornoway were more likely to come from non-island, high status and exogamous families, as compared with rural areas. Demographic differences within the rural areas themselves were not marked, but there was a tendency for eastern families to be intermediate between those from the west of the island and those from Stornoway. Differences in physical measurements were confined largely to those associated with weight (weight itself; ponderal index; fat); linear measurements showed few differences. Boys from the west of the island were significantly the heaviest and fattest. It seems likely that environmental (possibly dietary) rather than genetic factors are responsible for this difference. Rather surprisingly, advancement in puberty ratings in males was associated with an increase in linearity of build. This result was not found in females. Compared with U.K. standards, Lewis children in this age group are lighter, but of approximately the same stature.
This study was designed to investigate the relationship between body density and anthropometric dimensions in 8 to 11 year old boys for two samples of children located in different regions of the United States. It was hypothesized that similar anthropometric sites would be found to be the best predictors of body density in both samples leading to a common prediction equation for this age group. The samples consisted of 97 boys from Champaign-Urbana, Illinois and 86 boys from Davis, California. All subjects were measured for five skinfolds, five circumferences, six skeletal widths and body density estimated from hydrostatic weighing and pulmonary residual volume measurements. The precision of predicting body density from anthropometric dimensions was generally found to be as high as observed in adult samples. Skinfold thicknesses were better than circumferences or widths in predicting body density in each sample, although regression equations based on a combination of skinfolds, circumferences and widths resulted in slightly more precise estimates of body density. Two findings supported the development of a common equation for this age group. First, similar anthropometric sites were found to be applicable to both samples. Second, the curvilinear nature of the relation of skinfolds to body density was found in both samples. However, two additional findings prevented proposing one general equation: 1) a significant mean difference in predicting values between samples using the same anthropometric sites, and 2) a significant difference in density prediction error between samples. Separation of methodological from biological variability in the relation between density and anthropometry is needed prior to the development of a common approach to the prediction of body composition from anthropometry for this population.
Body size, physique and body composition were measured on 41 competitive female swimmers 11 through 20 years of age. All but one of the swimmers were post-menarcheal, and were actively engaged in a competitive swimming program. Anthropometric variables included height, weight, selected breadths, girths and skinfolds, and a Heath-Carter anthropometric somatotype. Body composition was determined by hydrostatic weighing procedures. All measurements were taken during the peak of the competitive season. Among the variables measured, only the limb circumferences differed significantly among the three age groups considered: 11-14, 15-17 and 18-20 years. There were no age-associated differences in density (1.0624 ± .009 g/cc for the entire sample) and percentage fatness (16.2 ± 3.7%). As a group, the swimmers were meso-ectomorphic, with an average somatotype of 2.9/3.7/3.6. Predicted body density in the swimmers, based on seven equations from non-athletic populations of a similar age range, consistently overestimates fatness.
Mean heights and weights for 205 boys aged 6-11 years in South Tunisia are compared with mean heights and weights of boys in the same age groups from India, Egypt and the U.S.A. Generally, boys from India rank lowest, Tunisian boys second lowest followed by the Egyptians and the U.S.A. boys with the highest means. Duncan Multiple Range Test was used to group each of the mean weights and heights of all ages from all countries into homogeneous subsets of similar magnitude. A similar height and weight is reached by the American boys about two years earlier than by the Tunisian boys. Skinfold comparisons for the triceps and subscapular skinfolds between the Tunisian and U.S.A. boys show that the Tunisian boys have between 16% and 49% lesser skinfold measurements with differences increasing with age. In comparing mean heights and weights of a Tunisian privileged group with the average U.S.A. group on the one hand and Tunisian village group on the other hand, differences found are much greater between the two Tunisian groups of the same racial background but different socioeconomic status than between the privileged Tunisians and the U.S. Americans of similar socioeconomic status but different racial background. (10 references)
Using isoelectric focusing and immunoblotting techniques, we tested 270 plasma samples from 3 populations of Senegal (Wolof, Peul, Tukulor) to determine genetic variation at 7 protein loci (F13A, F13B, ORM1, AHSG, C6, C7, APOC2). Four of the seven systems (F13A, ORM1, AHSG, C6) have not been studied previously in sub-Saharan Africa, and one system (C7) has never been examined in any population of African ancestry. The assumption that F13B*6, F13B*23, and APOC2*2 represent African marker alleles is supported by this study. At the AHSG locus we observed a four-allele polymorphism rather than the two-allele polymorphism commonly seen in other ethnic groups. At the C6 locus, in addition to the two common alleles C6*A and C6*B, we observed three other alleles, one of which (C6*A3), found at polymorphic frequencies, seems to be another example of a unique African allele. The C7 locus was found to be monomorphic in the Peul but polymorphic in the Wolof and the Tukulor. At the F13A and ORM1 loci, Senegalese have allele frequencies similar to those reported for American blacks. All three Senegalese samples display typical African features, such as a high frequency of the F13B*2 allele and the presence of the APOC2*2 allele at a polymorphic level. However, some differences in allele frequencies have been found between the three groups, and this could have implications for reconstructing their remote history.(ABSTRACT TRUNCATED AT 250 WORDS)
Origins of sampled individuals.
Multidimensional scaling plot depicting the genetic relationships of 16 world populations based on six Alu insertion loci (PV92, ACE, APOA1, TPA25, B65, A25). grm, Germans; fre, French; bret, Bretons; gre, Greek Cypriots; swis, Swiss; posht, Poshtoon; bag, Bagvalals; geor, Georgians; turc, Turkish Cypriots; lez, Lezgis; tab, Tabassarans; avr, Avars; turk, Turks from Anatolia; dar, Dargins; cham, Chamalals; andi, Andis.
We examined genetic variation in nine populations of Dagestan using 11 autosomal Alu insertion polymorphisms to investigate the genetic structure of indigenous groups and to assess their genetic relationship with world populations. Genetic differentiation among mountain inhabitants (Gsr = 2%) is comparable to that for European populations. Traces of genetic drift are detectable only for endogamous and small Ando-Dido-speaking ethnic groups, and they coincide with the most linguistically diverse region of Dagestan. Multidimensional scaling analyses among West Eurasian populations revealed that mountain inhabitants of Dagestan are closely related to Anatolian and Cyprus Turks. Thus our frequency data are consistent with the available Y-chromosome data, according to which the Middle East and the Caucasus share a considerable portion of the gene pool. Overall, our results corroborate the initially suggested genetic contribution of Middle Eastern populations to Caucasus populations.
Using restriction fragment length polymorphisms (RFLPs) and sequence haplotype analysis, we studied the chromosomal background of the beta-globin gene in 31 unrelated Lebanese IVS-I-110 or codon 39 (Cd39) subjects, and five normal betaAbeta/A individuals. Our results are compared with those from similar studies in other parts of the Mediterranean in an attempt to provide insights into historical patterns of selection and disease. The great majority of the Lebanese chromosomes with the IVS-I-110 mutation are associated with the RFLP haplotype I and sequence haplotype HT1, which is probably the ancestral structure on which the mutation first emerged. The remainder of the IVS-I-110 alleles are linked to the 5'-subhaplotype 12 RFLP haplotype and/or HTR sequence haplotype. In contrast, in Turkey, IVS-I-110 is associated with six distinct sequence haplotypes and four distinct RFLP haplotypes, suggesting that the mutation probably emerged there. The diversity of sequence haplotypes described in Turkey was probably generated through recombination or gene conversion events with the most frequent betaA autochthonous structures. Our data on Lebanese betaA chromosomes and Algerian betaA chromosomes, along with previously described Turkish betaA chromosomes, strengthen this hypothesis. Following its emergence in Turkey, the IVS-1-110 mutation was probably introduced to Lebanon later, by migration or settlements. Cd39 demonstrates a remarkable level of sequence and RFLP haplotype heterogeneity in Algeria, in contrast to its relative homogeneity in Turkish samples. However, its rarity in the Near East, and more specifically in Lebanon, does not allow us to draw any conclusions concerning its origin and gene flow.
The 111 females of the serial experimental sample of the Burlington Growth Centre were assigned to four groups by age of maximum increments in height. Mean height, weight and mandibular length were determined for each group at ages 8 to 14 and 16: and weight at the time of maximum gain in weight. Variance in the three variables at the times of their maximum increments, and at ages 8 to 14, and 16 were determined for the total sample. The earlier the statural maturity of the group: the greater was their mean weight, height and mandibular length; the greater was their weight for their height, and weight for mandibular length; and the greater was their gain in weight, height and mandibular length from age 8 to 12. By age 16 the late statural maturers had caught up to the early maturers in height but not in mandibular length. Maximum increments in weight did not occur at an invariant mean weight: early maturers in stature weighed more than late maturers. Variance in weight as well as in height and mandibular length was less at time of maximum increments in height than at time of maximum increments in weight or mandibular length.
Based on sequencing data and results obtained from applying a tailored mismatch polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, we report that the G allele of the mitochondrial DNA (mtDNA) polymorphism at nucleotide position 11719 is associated with the European mtDNA haplogroup cluster HV, and that 11719A is therefore the ancestral allele.
From the powder of ancient human bones (200 to 1500 years old) several proteins were isolated by saline extraction. Analysis of these components by polyacrylamide gel electrophoresis and immunoelectrophoresis gave no indication for the presence of serum proteins. Analysis of the purified saline insoluble material showed an amino acid composition similar to that of collagen and in one bone a positive reaction with a collagen radioimmunoassay. The migration of the proteins in SDS polyacrylamide gels revealed a multiple banded pattern with a high tendency to aggregate and a poor resolution in α1 and α2 bands. After cyanogen bromide cleavage several bands of low molecular weight could be resolved, indicating the occurrence of preserved methionine residues.
Methionine homozygosity at codon 129 of the prion protein gene is a risk factor for Creutzfeldt-Jakob disease. Knowledge of M129V polymorphism in normal populations may contribute to a better understanding of prion diseases. M129V polymorphism was studied in 2201 normal subjects, originating from 15 populations from Europe and the Middle East. Mean heterozygosity in these populations is 38.9%, and there is some significant geographic heterogeneity between them. A comparison of M129 allele frequencies in these 15 populations to those already published for 8 European countries plus Turkey shows significant correlations with both latitude (r = -0.77) and longitude (r = 0.69). The geographic map of methionine allele frequencies indicates an east-west gradient of decreasing methionine allele values from the Middle East to Western Europe.
Plasminogen is a hemostasis-related phenotype and is commonly implicated in thrombotic and bleeding disorders. In the San Antonio Family Heart Study (SAFHS), we performed to our knowledge the first genomewide linkage scan for quantitative trait loci (QTLs) that influence the level of plasminogen. The subset of the SAFHS population used for this study consists of 629 individuals distributed across 26 extended Mexican American families. Pedigree-based variance component linkage analyses were performed using SOLAR. The mean plasminogen level was 114.94% +/- 17.8 (range, 42-195). The heritability (h2) of plasminogen was 0.43 +/- 0.08 (p < 6.3 x 10(-13)). One region on chromosome 12 (12q14.1) showed suggestive evidence of linkage (LOD = 2.73, nominal p < 0.0002, genomewide p = 0.0786) near marker D12S1609. Because plasminogen has important effects in many human health problems, such as cancer and atherosclerosis, the role of this putative QTL in the regulation of plasminogen variability needs to be studied further.
To determine whether a common quantitative trait locus (QTL) influences the variation of fasting triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) levels, we used a bivariate multipoint linkage analysis with 654 polymorphic markers in 99 white and 101 black families. The phenotypes were investigated under two conditions: at baseline and after a 20-week exercise training intervention. A maximum genome-wide bivariate LOD score of 3.0 (p = 0.00010) was found on chromosome 12q23-q24, located within the IGF1 gene (insulin-like growth factor 1, at 107 cM) for TG and HDL-C at baseline in whites. This bivariate linkage peak is considerably higher than the univariate linkage results at the same chromosome location for either trait (for TG, LOD = 2.07, p = 0.00108; for HDL-C, LOD = 2.04, p = 0.00101). The genetic correlations between baseline TG and HDL-C levels were -0.14 for the residual and -0.33 for the QTL components. Moreover, association analysis showed that TG, HDL-C, and IGF1 are significantly associated (p = 0.04). In conclusion, these results suggest that a QTL on chromosome 12q23-q24 influences the variation of plasma TG and HDL-C levels. Further investigation should confirm whether IGF1 or another nearby gene is responsible for the concomitant variation in TG and HDL-C levels.
When activated, thrombin activatable fibrinolysis inhibitor (TAFI) inhibits fibrinolysis by modifying fibrin, depressing its plasminogen binding potential. Polymorphisms in the TAFI structural gene (CPB2) have been associated with variation in TAFI levels, but the potential occurrence of influential quantitative trait loci (QTLs) located elsewhere in the genome has been explored only in families ascertained in part through probands affected by thrombosis. We report the results of the first genome-wide linkage screen for QTLs that influence TAFI phenotypes. Data are from 635 subjects from 21 randomly ascertained Mexican American families participating in the San Antonio Family Heart Study. Potential QTLs were localized through a genome-wide multipoint linkage scan using 417 highly informative autosomal short tandem repeat markers spaced at approximately 10-cM intervals. We observed a maximum multipoint LOD score of 3.09 on chromosome 13q, the region of the TAFI structural gene. A suggestive linkage signal (LOD = 2.04) also was observed in this region, but may be an artifact. In addition, weak evidence for linkage occurred on chromosomes 17p and 9q. Our results suggest that polymorphisms in the TAFI structural gene or its nearby regulatory elements may contribute strongly to TAFI level variation in the general population, although several genes in other regions of the genome may also influence variation in this phenotype. Our findings support those of the Genetic Analysis of Idiopathic Thrombophilia (GAIT) project, which identified a potential TAFI QTL on chromosome 13q in a genome-wide linkage scan in Spanish thrombophilia families.
Hand reaction time (RT) and movement time (MT) measures were secured annually on a sample of 146 boys from ages 7 to 13 as part of the Saskatchewan Child Growth and Development Study. Total body reaction time (BRT) increases were secured on the same subjects for the ages 10 through 13 years. Analyses of the data showed a significant decrease in time (increasing speed) from 7 to 11 years for hand RT and from 7 to 9 yr for hand MT with a plateau occurring thereafter. BRT decreased significantly (increasing speed) with advancing age over the entire age range studied (10 to 13 years). Analysis of the data to investigate the influence of selected parameters (socio economic level, skeletal age, sports activity, body fat, strength and aerobic power) on RT, MT and BRT was performed by comparing times secured from extreme groups. Results indicated that of the factors studied only strength was important in terms of hand RT and BRT.
Geographic patterns of genetic diversity allow us to make inferences about population histories and the evolution of inherited disease. The statistical methods describing genetic variation in space, such as estimation of genetic variances, mapping of allele frequencies, and principal components analysis, have opened up the possibility to reconstruct demographic processes whose effects have been tested by a variety of approaches, including spatial autocorrelation, cladistic analyses, and simulations. These studies have significantly contributed to our understanding of human genetic variation; however, the molecular data that have accumulated since the mid-1980s have also created new complications. Reasons include the generally limited sample sizes, but, more generally, it is the nature of molecular variation itself that makes it necessary to develop and apply specific models and methods for the treatment of DNA data. The foreseeable diffusion of laboratory techniques for the rapid typing of many DNA markers will force us to change our approach to the study of human variation anyway, moving from the gene level toward the genome level. Because extensive variation among loci is the rule rather than the exception, an important practical tip is to be skeptical of inferences based on single-locus diversity.
Matrix gamma-carboxyglutamic acid protein (MGP) genotypes (G-7A and T-138C) were determined in 266 individuals from three Mexican populations. Mexicans showed increased frequencies of the G-7A G allele and the G7-A GG genotype compared to Europeans. For the T-138C genotype, we found differences among the Mexicans. This study could help to define the significance of MGP polymorphisms as genetic markers in Amerindian populations.
The interpolation map of frequency distribution of the lactase persistence associated allele -13915*G in the Arabian Peninsula and surrounding countries.  
Figure A1. Principal Coordinate Analysis (PCA) showing the major patterns within the multivariate data sets of the LP-associated -13910*T and -13915*G variants in five subpopulations in the Arabian Peninsula. Arab of Northern Oman (ANO), Omani of Asian Origin (OAO), Dhofari Arabs of Southern Oman (DFR), Yemenis (YMN), and Saudis (KSA).  
Abstract The high prevalence of lactase persistence (LP) among the people of Saudi Arabia is associated with the -13915(*)G variant allele upstream of the lactase gene (LCT). We, therefore, examined the frequency of the commonly known LP associated SNPs among randomly collected samples from Omani and Yemeni adult populations and obtained further data on the distribution of the two most common LP-associated variants, -13910(*)T and -13915T(*)G, in the Arabian Peninsula. The DNA fragment containing all the reported LP- associated SNPs was amplified and genotyped. The frequency of the -13915(*)G allele was highest among Dhofari Arabs of southern Oman (0.72) followed by Yemeni Arabs (0.54) and Arabs of northern Oman (0.14). It was not detected in Omanis of Asian origin. The frequency of the -13910(*)T allele was extremely low in Arabs of northern and southern Oman (0.00-0.01) and Yemenis (0.002). However, it had a frequency of 0.160 among Omanis of Asian origin. Results show that the highest frequency of the LCT -13915(*)G variant allele appears to be in the south of the Arabian Peninsula with clinal decrease within the Peninsula and further out in surrounding countries.
Although difficult to estimate for prehistoric hunter-gatherer populations, demographic variables-population size, density, and the connectedness of demes-are critical for a better understanding of the processes of material culture change, especially in deep prehistory. Demography is the middle-range link between climatic changes and both biological and cultural evolutionary trajectories of human populations. Much of human material culture functions as a buffer against climatic changes, and the study of prehistoric population dynamics, estimated through changing frequencies of calibrated radiocarbon dates, therefore affords insights into how effectively such buffers operated and when they failed. In reviewing a number of case studies (Mesolithic Ireland, the origin of the Bromme culture, and the earliest late glacial human recolonization of southern Scandinavia), I suggest that a greater awareness of demographic processes, and in particular of demographic declines, provides many fresh insights into what structured the archaeological record. I argue that we cannot sideline climatic and environmental factors or extreme geophysical events in our reconstructions of prehistoric culture change. The implications of accepting demographic variability as a departure point for evaluating the archaeological record are discussed.
In this descriptive study we investigated the genetic structure of 513 Mexican indigenous subjects grouped in 14 populations (Mixteca-Alta, Mixteca-Baja, Otomi, Purépecha, Tzeltal, Tarahumara, Huichol, Nahua-Atocpan, Nahua-Xochimilco, Nahua-Zitlala, Nahua-Chilacachapa, Nahua-Ixhuatlancillo, Nahua-Necoxtla, and Nahua-Coyolillo) based on mtDNA haplogroups. These communities are geographically and culturally isolated; parents and grandparents were born in the community. Our data show that 98.6% of the mtDNA was distributed in haplogroups A1, A2, B1, B2, C1, C2, D1, and D2. Haplotype X6 was present in the Tarahumara (1/53) and Huichol (3/15), and haplotype L was present in the Nahua-Coyolillo (3/38). The first two principal components accounted for 95.9% of the total variation in the sample. The mtDNA haplogroup frequencies in the Purépecha and Zitlala were intermediate to cluster 1 (Otomi, Nahua-Ixhuatlancillo, Nahua-Xochimilco, Mixteca-Baja, and Tzeltal) and cluster 2 (Nahua-Necoxtla, Nahua-Atocpan, and Nahua-Chilacachapa). The Huichol, Tarahumara, Mixteca-Alta, and Nahua-Coyolillo were separated from the rest of the populations. According to these findings, the distribution of mtDNA haplogroups found in Mexican indigenous groups is similar to other Amerindian haplogroups, except for the African haplogroup found in one population.
Among 346 school children 6 to 14 years of age in Oaxaca, Mexico, stature and weight are significantly correlated with measures of metacarpal cortical bone. As stature and weight are highly correlated measures of body size, their correlations with metacarpal bone are of similar magnitude. However, there are separable stature and weight correlates to measures of metacarpal bone, stature being the best predictor of bone dimensions. When compared to U.S. Mexican American children, the Mexican children of Oaxaca have smaller metacarpal dimensions than would be expected from their body size.
Tetracycline-labeling of bone is a phenomenon well established in the literature and recently has been discovered in archaeological human bone of some antiquity. This is the second reported finding of tetracycline-labeled human bone from Sudanese Nubia. This study examines the biocultural implications of the tetracycline and its possible relationship to the incidence of disease and overall patterns of health in a population from Nubia's Batn el Hajar. Analysis of the bone for the presence of both tetracycline and infectious lesions showed low levels of the former and moderate levels of the later, but no statistical relationships between the two. The present data suggest that the occasional ingestion of low concentrations of tetracycline had no positive impact on disease in this population.
A new member of the human RNase A superfamily is reported. Identified in the human genome assembly as LOC 390443, this locus is located 128 kb telomeric to the established RNase A gene family cluster on chromosome 14q11.2. The amino acid sequence of this locus is sufficiently similar to the eight previously identified gene family members to warrant a designation as RNase 9. RNase 9 is expressed in a wide range of human tissues. In addition, a 30-amino acid sequence lying between a 26-amino acid putative signal peptide and the last 148 amino acids that align with the other RNases A is not seen in other members of the RNase A superfamily in any species. Nucleotide and amino acid sequences of RNase 9 in 13 nonhuman primate species were determined and indicate several conserved sites but, also, an excess of nonsynonymous substitutions, about one-third of which are radical substitutions. This suggests that RNase 9, similar to several other human RNases A, has been under diversifying selection in the primates. Data from the mouse and rat genomes indicate that RNase 9 is also present in rodents, thus making it older than most of the established members of the human RNase A superfamily. Many of the human RNases A have been shown to have antimicrobial, antiviral, or antiparasitic functions involved in host-defense mechanisms. The features of RNase 9 described here suggest that it, too, may be involved in host defense and that it, along with the rest of the superfamily, may prove to have played an important role in anthropoid evolution.
The Black Death epidemic of 1347-1351 was one of the most serious catastrophes in human history, yet it continues to be imperfectly described because of the small and often uncertain amount of information recorded and preserved. Analysis of data from 53 cities, with 200 to 120,000 residents, shows a relationship between urban population at the beginning of the epidemic and duration of the epidemic, thus throwing some light on the characteristics of the pestilence. A further relevance of the finding is its utility for estimating and resolving contradictory information. On a first application, we show that the population and fatalities of London in all likelihood were higher than the most widely accepted estimates and that those of Florence and Paris must have been smaller.
Haplotype determination based on three Y-linked polymorphic sites, 92R7 (C/T), SRY-1532 (A/G), and YAP (-/+), in 127 males belonging to three caste Hindu populations of South India (Vizag Brahmins, Peruru Brahmins, and Kammas) and 13 males belonging to a migrant group (the Siddis) showed the existence of all four haplotypes (CA-, CG-, TG-, and TA-) under the YAP- background. This finding suggests that the reverse mutation (G-->A) at the SRY-1532 site, described earlier in the literature, is present in South Indian populations as well. The YAP+ mutation was seen in only five Siddi individuals. Four of these were of the CG+ haplotype structure, but a novel haplotype (CA+) was found in one male. To explain the occurrence of the six haplotypes found within these three sites, a haplotype tree is constructed that introduces a new reverse mutation at the SRY-1532 site (G-->A), occurring under the CG+ background after the migrant Siddi population arrived in India.
Sociocultural factors play a crucial role in the variation of consanguinity in a population. The choice of specific matrimonial strategies can favor the closure or opening of the group to the outside, whereas differential fertility affects the gene flow from one generation to another. In the present study we analyzed the role of socioprofessional groups in the maintenance of endogamy and consanguinity in a French Alpine valley: Vallouise in the Briançon area. In mountain environments, where the reproductive space is limited and quickly saturated, the autochthonous families adopt diversified matrimonial strategies. These marriage practices tend to prevent fragmentation of agricultural property. We analyzed the matrimonial behavior in the two main social groups of this population (décideurs and farmers) from 1550 to 1849. To better understand the behavior of the two social groups, we considered the two components of consanguinity, close and distant. Our study showed that the two groups had similar behavior regarding consanguinity. The way to prevent fragmentation of the patrimony was to choose a consanguineous spouse. This type of strategy inevitably leads to a high percentage of endogamy, which in this region of the Alps exceeded 90% through many centuries.
Microgeographic variations in the frequency of consanguineous marriages and historical change in inbreeding were analysed in an Italian mountain population. From 1565 to 1980 in the 35 parishes of the Upper Bologna Appennine 3532 dispensations for marriages up to the third cousin degree of relationship were recorded in a total of 43252 marriages. The average frequency of consanguineous marriages was 8.17% and the mean inbreeding coefficient was α = .00125. Within the mountain region marked microgeographic variations in inbreeding related to environmental and geographic factors were observed. There are microgeographic differences in pedigree structure. As a consequence of female virilocal migration the tendency for a higher frequency of pedigrees with more intermediate male ancestors was reduced in the more inbred and more isolated upper valley subpopulation. In the second half of the nineteenth century historical change in inbreeding values was characterized by a sudden increase in close consanguineous marriages. During the last decades of this century the decrease in consanguineous marriages was connected with the phenomenon of the breakdown of isolates. A high correlation (r = .98) between inbreeding increase and population growth has been stressed suggesting that the secular trend in inbreeding may depend on demographic factors in addition to social and historical events.
Genetic polymorphisms for six blood groups, three red cell enzymes, three serum proteins, and hemoglobin were examined in sixteen central Indian tribal populations. Nine of the tribes belonged to Orissa, five to Madhya Pradesh, and two to Maharashtra. Eleven tribes spoke the Dravidian language, three Indo-Ayran, and two the language of the Austro-Asiatic families. The population structure of these tribal populations was analyzed at the inter- and intrastate and linguistic levels, using data for 13 genetic systems (38 alleles or haplotypes). Nine of the 13 loci showed significant heterogeneity in the 16 tribes, and the pattern of heterogeneity was also discernible in the different states and in the Dravidian-speaking tribes. As expected, the extent of genetic differentiation or gene diversity was the highest so far reported from central India. The mean FIS and HS for each locus in the different state, linguistic, and total tribal groups were consistently higher than the FST and GST values, respectively, showing that the genetic structure of each tribe is highly influenced by inbreeding. In a genetic affinity analysis by genetic distance the Indo-Aryan and Austro-Asiatic language groups showed little affinity with each other, although there was some tendency toward geographic affinity. The present analysis indicates that, in addition to genetic drift, gene flow, and selection, the genetic structure of the populations of central India is also highly influenced by sociocultural adaptation and inbreeding.
V̇o2 max has been measured in 106 White, 217 Mestizo and 70 Black boys 6-16 years of age in Colombia. Subjects were selected for nutritional normality by including only those within ± 5% of Columbian norms of weight for age and weight for height. There were no racially based differences in total V̇o2 max (L/min), when V̇o2 max was expressed in terms of body weight (ml/kg/min) or in the regression lines of V̇o2 max (L/min) on body weight. Nor did socioeconomic status influence the maximum exercise response of these children.
Top-cited authors
Harry Ostrer
  • Albert Einstein College of Medicine
Carlos D. Bustamante
  • Stanford Medicine
Fredy Zakharia
  • Indonesian Adventist University
Jeremiah D Degenhardt
  • Maverick Therapeutics Inc
Robert L Bettinger
  • University of California, Davis