Distribution of ADH2 and ALDH2 genotypes in different populations

Summary The distribution of the human liver alcohol dehydrogenase, ADH₂, and aldehyde dehydrogenase, ALDH2, genotypes in 21 different populations comprising Mongoloids, Caucasoids, and Negroids was determined by hybridization of the amplified genomic DNA with allele-specific oligonucleotide probes. Whereas the frequency of the ADH ₁ ² allele was found to be relatively high in the Caucasoids, Mexican Mestizos, Brazilian Indios, Swedish Lapps, Papua New Guineans and Negroids, the frequency of the ADH ₂ ² gene was considerably higher in the Mongoloids and Australian Aborigines. The atypical ALDH2 gene (ALDH2²) was found to be extremely rare in Caucasoids, Negroids, Papua New Guineans, Australian Aborigines and Aurocanians (South Chile). In contrast, this mutant gene was found to be widely prevalent among the Mongoloids. Individuals possessing the abnormal ALDH2 gene show alcohol-related sensitivity responses (e.g. facial flushing), have the tendency not to be habitual drinkers, and apparently suffer less from alcoholism and alcohol-related liver disease.     

Investigations on the genetics and population genetics of the β2 polymorphism

Summary The results of studies on 49 families with 107 children and various populations of Caucasoid, Negroid and Mongoloid origin concerning the genetics and population genetics of the ₂-glycoprotein I polymorphism are reported. In general the genetical model proposed by Cleve (1968) is confirmed: two autosomal alleles Bg^N and Bg^D controlling the phenotypes Bg N-N, Bg N-D and Bg D-D. However, divergences from this model were found in two families. They indicate the assumption of non-genetic factors influencing the phenotype expression rather than more complicated genetical control mechanisms. Within Caucasoid populations phenotype and gene frequencies show almost a homogeneous distribution. This racial stock is striking due to a significant higher ₂-glycoprotein I concentration in serum as compared to Negroids and Mongoloids. In connection with this, these racial stocks differ obviously in the gene frequencies: Caucasoids Bg^N=0.937, Negroids=0.742, Mongoloids =0.780; resp. Bg^D=0.063, 0.258, 0.220.Supported by the Deutsche Forschungsgemeinschaft.D 77.     

Comparative study of the upper molar occlusal table morphology among seven human populations

Three-dimensional morphology of the occlusal table of the upper first molars was compared in seven racial populations. Materials were moiré contourograms collected by ourselves over 5 years. Intercuspal distances and cuspal heights were comparatively studied in this analysis. When the populations were arranged in the order of these sizes, their arrangements based on intercuspal distances and cuspal heights were quite different from each other. When intercuspal distances were scaled by protocone-paracone distance, the distances connecting distal cusps were significantly smaller in Mongoloids (Japanese and Eskimo) than in Caucasoids (Dutch and Asiatic Indian), which suggests a reduction tendency of distal cusps in Mongoloids. This tendency was intermediate in Negroids and Australoid. Principal coordinate analysis was carried out on the basis of a similarity matrix including both intercuspal distances and cuspal heights. The result suggested that the three-dimensional shape of the occlusal table was distinguishable in four representative racial populations.     

Frequency of the musculus palmaris longus studied in vivo in some Amazon indians

The frequency of the Musclus palmaris longus was studied by observing its tendon in vivo in 379 Amazon Indians belonging to the following tribes: Tucano, Tariana, Tiriyo, Desana, Piratapuya, Macu and Arapaso. The muscle was not observed in 14 individuals (3.7% ± 1.0) either unilaterally or bilaterally and in 24 of 758 limbs (3.1% ± 0.6). No statistically significant difference was observed in the frequency of the muscle among the different tribes. Bilateral absence was significantly more frequent than the unilateral one; absence in females was more frequent than in males. The frequency of palmaris longus agenesis in Amazon Indians agrees with reported values for Negroids and Mongoloids and is considerably lower than that generally reported for the Caucasoids.     

The distribution of esterase D variants in different ethnic groups

Summary Blood samples collected from a number of human populations belonging to various ethnic groups were screened on cellogel for red-cell esterase D (ESD) variants. These data gathered during the present study together with those that have already appeared in the literature indicate that the common variant allele ESD ² occurs most frequently in the Mongoloid populations, least frequently in the Negroid, and with intermediate frequencies in the Caucasoids. An east to west cline was noticed in the northern populations of the Indian subcontinent; ESD ² gene frequencies in these populations were found to range between those among the Mongoloids and the Caucasoids.     

Do r/K reproductive strategies apply to human differences?

This article discusses the r/K theory of Social Biology and how it relates to humans. The symbols r and K originate in the mathematics of population biology and refer to 2 ends of a continuum in which a compensatory exchange occurs between gamete production (the r-strategy) and longevity (the K-strategy). Both across and within species, r and K strategists differ in a suite of correlated characteristics. Humans are the most K of all. K's supposedly have a longer gestation period, a higher birthweight, a more delayed sexual maturation, a lower sex drive, and a longer life. Studies providing evidence for the expected covariation among K attributes are presented. Additional evidence for r/K theory comes from the comparison of human population known to differ in gamete production. The pattern of racial differences observed to occur in sexual behavior has also been found to exist on numerous other indices of K. For instance, there are racial differences in brain size, intelligence, and maturation rate, among others. The findings suggest that, on the average, Mongoloids are more K than Caucasoids, who in turn, are more K than Negroids. Recently conducted studies have extended the data in favor of r/K theory, and further research is currently underway, including whether r/K attributes underlie individual and social class differences in health and longevity.     

Race differences in the sex dimorphism of dermatoglyphic traits

For three dermatoglyphic traits it could be proved that there are racial differences in sex dimorphism. The results are as follow: (1) For the index of pattern intensity (158 samples), the sex difference is significantly higher in Negroids than in Europoids and Mongoloids. (2) For total ridge count, the sex difference is lower in Negroids than in Europoids. The discrepancy between (1) and (2) has been discussed. (3) The number of samples with higher frequencies of palmar patterns in males than in females is significantly higher in Negroids than in Mongoloids and Europoids for the hypothenar and III interdigital and lower in Mongoloids than in Europoids and Negroids for the II interdigital (max. 127 samples).     

Sex ratio changes and the evolution of eusociality in the hymenoptera: Simulation and games theory studies

Computer simulations of the evolution of altruistic (worker) behaviour with concomitant sex ratio biasing by female Hymenoptera were used to calculate K_min, the minimum K preventing selection against altruism. K is the ratio of the number of siblings raised by a worker, to the number of offspring she would have raised otherwise. The results were compared to a games theory analysis of the same system.The simulation results agreed exactly with games theory predictions under Hardy-Weinberg conditions, but deviated from them somewhat during selection. K_min varied with P (the proportion of altruists). If altruists made the sex ratio more female-biased, K_min < 1 at low P, but with reasonable brood sizes K_min > 1 at high P. If queens raised a second brood, simultaneously with brood raised by altruists, the value of K_min at high P was reduced with decreasing brood size. Decreasing the degree of female-bias generally caused a decrease in K_min with increasing P; altruism with sex ratio biasing toward males was always selected against. Simulations confirmed that selection is positive when K > K_min and negative when K < K_min. Thus altruism can be favoured by sex ratio biasing while P is low, but as P increases it becomes increasingly disadvantaged relative to altruism without sex ratio biasing (when K ? 1 at all P). It is concluded that sex ratio biasing is not particularly favourable for the evolution of social behaviour in Hymenoptera.     

Polymorphism of Human Thermoreceptor Genes <Emphasis Type="Italic">TRPV1</Emphasis> and <Emphasis Type="Italic">TRPA1</Emphasis> in Populations of the Altai-Sayan Region and the Far East

Genotyping of TRPV1 and TRPA1 genes encoding thermoreceptors in the populations of the Altai-Sayan region and the Far East was conducted. The sample consisted of 15 populations comprising 1482 individuals. The analysis of TRPV1 rs222747 demonstrated that the frequency of M315I was closest to East Asian populations only in Nanais and Koryaks (56 and 64%, respectively). Siberian Tatars, Yakuts, and Evenks were closest to European populations. All populations of the Altai-Sayan region reported an intermediate position between the Caucasoids and the Eastern Mongoloids on the basis of the frequency of M315I. No deviations from the Hardy–Weinberg distribution were observed. The observed heterozygosity exceeded the expected one in eight populations. The analysis of TRPA1 rs13268757 revealed that Chukchi, Yukaghir, Koryak, Tuvinian, Southern Altaian, and Telengit populations were closest to the East Asian populations on the basis of the frequency of R3C substitution (3–7%). At the same time, populations of Siberian Tatars, Nanais, Evenks, Yakuts, Shorians, Khakases, and Kazakhs were intermediate between the Caucasoids (18–23%) and the Mongoloids from East Asia (3–7%) on the basis of the frequency of this polymorphism. A deviation from the Hardy–Weinberg distribution was detected only in the Yukaghir population. The observed heterozygosity was higher than the expected one in nine populations. A trans-association of TRPA1 and TRPV1 gene polymorphisms was carried out in 14 populations via regression analysis. A negative correlation of–0.545 was determined, the number of degrees of freedom (df) was 13, and the P-value was 0.048. The data obtained indicate that the analyzed polymorphisms are correlated, which confirms an earlier conclusion of the TRPA1-dependent inhibition of TRPV1 function. The results may evidence in the co-evolution of analyzed genes.     

Collateral relatives of American Indians among the Bronze Age populations of Siberia?

Nonmetric and metric traits were studied in cranial series representing prehistoric and modern populations of America and Siberia. Frequencies of the infraorbital pattern type II (longitudinal infraorbital suture overlaid by the zygomatic bone) are universally lower in Amerindians than in Siberians. The os japonicum posterior trace, too, is much less frequent in America than in Siberia. The only two Siberian groups with an almost Amerindian combination are late third to early second millennium bc populations from Okunev and Sopka, southern Siberia. The multivariate analysis of five nonmetric facial traits and ten facial measurements in 15 cranial series reveals two independent tendencies. One of them shows a contrast between prehistoric Siberian Caucasoids and modern Siberian Mongoloids; the second one sets Amerindians apart from others. Prehistoric people who lived west of Lake Baikal and modern Uralic speakers are intermediate between Siberian Caucasoids and Siberian Mongoloids; Eskimos, Aleuts, and Chukchi are intermediate between Siberian Mongoloids and Amerindians; and Okunev and Sopka are intermediate between Siberian Caucasoids and Amerindians. Our results suggest that people of Okunev and Sopka are collateral relatives of Amerindians with some Caucasoid admixture. Am J Phys Anthropol 108:193–204, 1999. © 1999 Wiley-Liss, Inc.     

Amerindians show no association of PPAR-γ2 gene Ala12 allele and obesity: an “unthrifty” variant population genetics

Obesity is for many scholars the most important starting status that gives rise to Metabolic Syndrome (MS) and Type 2 Diabetes (T2D). In the present paper, a genetically homogeneous Amerindian population, as defined by HLA genes, has been genotyped for one of the MS and T2D predisposing genes: PPAR-γ Ala12 and Pro 12 variants. Ala12 has been negatively associated with obesity, but other authors do not find such an association. Notwithstanding, a meta-analysis that used many subjects clearly demonstrated that PPAR-γ Ala12 bearing ones had a reduced risk for T2D. Our results show that Amerindians do not have association of PPAR-γ2 Ala12 and obesity; the latter was measured by waist circumference values after taken specific Amerindian normal waist parameters. Also, a population genetics study indicates that Pro12 allele was the wild allele, which must have occurred before modern humans left Africa. Ala12 may have appeared in Caucasoids later on, according to our comparisons. Negroids tend to show low or null Ala 12 allele frequencies, while most other populations have a significant frequency, particularly European Caucasoids. This may suggest that appearance of Ala12 allele occurred after populations adapted to an agricultural feeding.     

Genetic variation of five blood group polymorphisms in ten populations of Assam,India

Six Mongoloid and four Caucasoid populations of Assam, India, were examined for A₁A₂BO, Rhesus, Duffy and Diego blood groups. The distribution of their phenotypes and allele frequencies are presented. In the perspective of the ethnographic background, the results have been discussed in terms of genetic variability among these populations and probable reasons for its existence. The major groups, namely Caucasoids and Mongoloids, appear to form two separate groups in terms of these blood groups, though evidence is there to suggest intermixture.     

Resource Elasticity of Offspring Survival and the Optimal Evolution of Sex Ratios

The fitness of any organisms includes the survival and reproductive rate of adults and the survival of their offspring. Environmental selection pressures might not affect these two aspects of an organism equally. Assuming that an organism first allocates its limited resources to maintain its survival under environmental selection pressure, our model, based on the evolutionarily stable strategy theory, surprisingly shows that the sex ratio is greatly affected by the environmental pressure intensity and by the reproductive resource elasticity of offspring survival. Moreover, the concept of the resource elasticity of offspring survival intrinsically integrates the ecological concepts of K selection and r selection. The model shows that in a species with reproductive strategy K, increased environmental selection pressure will reduce resource allocation to the male function. By contrast, in a species with reproductive strategy r, harsher environmental selection pressure will increase allocation to the male function. The elasticity of offspring survival might vary not only across species, but also across many other factors affecting the same species (e.g., age structure, spatial heterogeneity), which explains sex ratio differences across species or age structures and spatial heterogeneity in the same species.     

Gm and Inv allotypes in a Gypsy sample.

Serum samples from 226 Gypsies were tested for Gm(1,2,4,5,8,10,11,14,17,21,23,25) and for Inv(1,2). The Gm phenotypes found are very numerous and the more frequent among this population are: Gm(4,5, 8,10,11,14,17,23,25) and Gm(1,2,4,5,8,10,11,14,17,21,23,25). All the phenotypes except three can be explained by nine haplotypes: Gm4,5,8,10,11,14,23,25, Gm1,4,5,8,10,11,14,23,25, Gm4,5,8,10,11,14,25, Gm1,17,21, Gm1,10,11,17,25, Gm1,2,17,21, Gm1,8,17,21, Gm1,8,17,21,23 and Gm1,5,10,11,14,17. The haplotypes Gm1,17,21, Gm1,2,17,21, Gm4,5,8,10,11,14,25 (with or without Gm[ 3]) are all three common among Caucasoids, Gm1,4,5,10,11,14,23,25 (common among Mongoloids) and Gm1,5,10,11,14,17 (common to Negroids). For the Inv system, this population possesses a very low frequency of Inv(1) and Inv(2).     

DENSITY-DEPENDENT EVOLUTION OF LIFE-HISTORY TRAITS IN DROSOPHILA MELANOGASTER

Populations of Drosophila melanogaster were maintained for 36 generations in r- and K-selected environments in order to test the life-history predictions of theories on density-dependent selection. In the r-selection environment, populations were reduced to low densities by density-independent adult mortality, whereas populations in the K-selection environment were maintained at their carrying capacity. Some of the experimental results support the predictions or r- and K-selection theory; relative to the r-selected populations, the K-selected populations evolved an increased larval-to-adult viability, larger body size, and longer development time at high larval densities. Mueller and Ayala (1981) found that K-selected populations also have a higher rate of population growth at high densities. Other predictions of the thoery are contradicted by the lack of differences between the r and K populations in adult longevity and fecundity and a slower rate of development for r-selected individuals at low densities. The differences between selected populations in larval survivorship, larval-to-adult development time, and adult body size are strongly dependent on larval density, and there is a significant interaction between populations and larval density for each trait. This manifests an inadequacy of the theory on r- and K-selection, which does not take into account such interactions between genotypes and environments. We describe mechanisms that may explain the evolution of preadult life-history traits in our experiment and discuss the need for changes in theories of density-dependent selection.     

Anatomical differences in the femur and tibia between Negroids and Caucasoids antheir effects upon locomotion.

Nine variables of length, width and circumference of the femur and tibia were measured on post-cranial remains of 28 Caucasoids and 45 Negroids. The distance from the point of tibial attachment of the patellar ligament to the head of the tibia (PLID) was also determined. It was found that the Negroid has a significantly longer and narrower femur and tibia than the Caucasoid, although PLID did not vary between the two groups. Thus PLID, relative to the length of the tibia, was less in Negroids than Caucasoids. A factor analysis was carried out in order to examine the relation between PLID and the other variables. It appeared that the same three factors governed the ten variables in both races. In Caucasoids, PLID did not load on either the "length" or "width" factors and appeared unique. In Negroids, PLID loaded on Factor III with two width measures, and this factor correlated positively with the "width" factor. It is suggested that in Caucasoids PLID does not relate to length or width dimensions of the leg but in Negroids it is related to width rather than length.     

Population genetic structure of Sagittaria natans (Alismataceae), an endangered species in China,revealed by nuclear SSR loci analyses

Sagittaria natans (Alismataceae) is an endangered aquatic herb in China. The nuclear microsatellite (SSR) loci variation of the 11 extant populations of S. natans was investigated in the present study. A relative high level of genetic diversity was found in this species. The Wilcoxon’s signed rank tests did not indicate a recent bottleneck in any of the populations. The Analysis of molecular variance (AMOVA) showed a low level of population differentiation (FST = 0.284) among the populations of S. natans. This result was supported by STRUCTURE analysis (K = 1), the NJ analyses and Mantel test (r = ?0.0221, p > 0.5). The genetic structure could be contributed to an earlier period of more pronounced gene flow when the species had a more continuous distribution. The results of this study could be used as the basis for conservation guidelines for the management of this endangered species in China.     

LIFE‐HISTORY EVOLUTION AND DENSITY‐DEPENDENT GROWTH IN EXPERIMENTAL POPULATIONS OF YEAST

We studied the evolution of the correlation between growth rate r and yield K in experimental lineages of the yeast Saccharomyces cerevisiae. First, we isolated a single clone every approximately 250 generations from each of eight populations selected in a glucose‐limited medium for 5000 generations at approximately 6.6 population doublings per day (20 clones per line × 8 lines) and measured its growth rate and yield in a new, galactose‐limited medium (with ～1.3 doubling per day). For most lines, r on galactose increased throughout the 5000 generations of selection on glucose whereas K on galactose declined. Next, we selected these 160 glucose‐adapted clones in the galactose environment for approximately 120 generations and measured changes in r and K in galactose. In general, growth rate increased and yield declined, and clones that initially grew slowly on galactose improved more than did faster clones. We found a negative correlation between r and K among clones both within each line and across all clones. We provide evidence that this relationship is not heritable and is a negative environmental correlation rather than a genetic trade‐off.     

Phenetic Analysis in Paleoanthropology: Phenogeography of Peoples of the World

Phenetic diversity of peoples of the world in a system of nonmetric, discrete variable traits has been studied. Sixty-two populations from North, Central, and Southeast Asia, Eastern and Western Europe, America, East Africa, Australia, and Melanesia have been examined. The estimates of phenetic diversity within regions (F_st) and the distances of the regions from the global means (d) proved to be comparable to the corresponding estimates inferred from genetic data. This means that differentiation of populations in discrete variable traits is related to the history of formation of their gene pools. A classification tree of the world peoples constructed using bootstrap implemented in the PHYLIP program package (Felsenstein, 1993) showed that the Australo-Melanesian populations were close to the East African ones but separated from those of the Eurasian region. The results of phylogenetic analysis of the reconstructed phene pools of the regional ancestral populations support the assumptions on the early colonization of Australia and Melanesia and on the later time of divergence of the ancestors of modern Caucasoids and North Asian Mongoloids.     

Anthropology and genetics of the caucasus peoples and the problem of the origin of the caucasoids

The electrophoretical polymorphisms of some blood proteins were studied in the Talysh population of Pirasora situated in South-East Azerbaidjan. We calculated the gene frequencies of these polymorphisms and determined the genetic distances between the Talyshes and some Iranian populations of North, Central and South Iran, Afghans, and three populations of Azerbaijan. The Talyshes are very close to Iranians of Shiraz, whereas they are distant from the Azerbaijanians. Anthropological investigations showed that the Caucasoids and Mongoloids lived in the Aragvi Basin since the Eneolithic period. This was stated by Alexeev (1974), who emphasized the mixture of the Caucasus populations from ancient times on. We calculated the genetic distances between the Caucasus populations and numerous populations of other geographic regions, considering 28 alleles of 12 loci of blood group, serum protein and red cell enzyme polymorphisms and constructed the dendrogram of these populations. The position of the Caucasus populations in the dendrogram corresponds on principle to the earlier anthropological observations. The clustering of the Caucasoid populations corresponds completely with anthropological and historical data, and supports our earlier hypothesis (Nazarova 1999) concerning the differentiation of Caucasoids, Northern Mongoloids and Amerinds from the populations, which inhabitated Asia in palaeolithic times.