Anthropometric studies in Brazilian Cayapo Indians

Results of 16 measurements and 7 indices obtained from 130 men and 156 women belonging to three populations of Brazilian Indians are reported. For both males and females the averages for stature and head breadth are in the middle of the distribution range of values observed in other South American tribes; those for head length and nasal height are relatively low but the averages for sitting height, calf circumference and minimum frontal breadth are high. As for the indices, in both sexes the cephalic and cephalofacial are medium, the Rohrer, jugomandibularis and facial low, and the nasal high when compared with other tribes. Morphological distances between the three Cayapo populations were estimated using Mahalanobis' D² statistic; they are smaller than those separating different tribes and are not the expected ones when the demographic variables of these groups and the geographic distances between them are considered. The amount of variability as expressed by the coefficient of variation and the prevailing pattern of sexual dimorphism are similar to those observed in other Indian populations.     

The genetic structure of a tribal population, the Yanomama indians. VII. Anthropometric differences among Yanomama villages

Anthropometric data on 12 variables in 19 villages of the Yanomama Indians demonstrate significant heterogeneity in physique among villages of this tribe. Mahalanobis' distances (D²) calculated from the data lead to the tentative conclusion of a general correspondence between anthropometric and geographic distances separating villages. The mean stature of the Yanomama is smaller than that of most other South American tribes which have been measured, and the Yanomama are genetically distinct from the other small Indians as shown by genetic distances based on allele frequencies for a variety of genetic markers. Since some subjects were measured more than once by the same and by different observers, it was possible to calculate approximate estimates of variance within and between observers. Univariate analysis indicates that face height and nose height are especially susceptible to systematic differences in technique between observers. The variances obtained in this field study compare favorably with those of some classical laboratory studies described in the literature. It was found that measurement error nevertheless probably makes a substantial contribution to anthropometric distance between villages. The median error variance as a fraction of that of Herskovits ('30) is 0.62 for the seven measurements in common with this study. The median value of the error variance for the 12 variables in this study is between 16% and 17% of the total variance.     

Genome-wide analysis in brazilian xavante indians reveals low degree of admixture

Characterization of population genetic variation and structure can be used as tools for research in human genetics and population isolates are of great interest. The aim of the present study was to characterize the genetic structure of Xavante Indians and compare it with other populations. The Xavante, an indigenous population living in Brazilian Central Plateau, is one of the largest native groups in Brazil. A subset of 53 unrelated subjects was selected from the initial sample of 300 Xavante Indians. Using 86,197 markers, Xavante were compared with all populations of HapMap Phase III and HGDP-CEPH projects and with a Southeast Brazilian population sample to establish its population structure. Principal Components Analysis showed that the Xavante Indians are concentrated in the Amerindian axis near other populations of known Amerindian ancestry such as Karitiana, Pima, Surui and Maya and a low degree of genetic admixture was observed. This is consistent with the historical records of bottlenecks experience and cultural isolation. By calculating pair-wise F(st) statistics we characterized the genetic differentiation between Xavante Indians and representative populations of the HapMap and from HGDP-CEPH project. We found that the genetic differentiation between Xavante Indians and populations of Ameridian, Asian, European, and African ancestry increased progressively. Our results indicate that the Xavante is a population that remained genetically isolated over the past decades and can offer advantages for genome-wide mapping studies of inherited disorders.     

Child growth and adult physique in Brazillan Xingu Indians

Data on stature, sitting height, biacromial width, and some other body measurements on 267 children and 363 adults of the Xingu Indians of Brazil have been analyzed. Adult height shows no significant decrease with age over an age range of 20–50 years, thus indicating the absence of secular changes. The average Xingu child seems to be around the twenty-fifth to fiftieth centile for height of British children (if our age estimates are correct) until about ten years in girls and 14 years in boys, but ends at below the third British centile as an adult. In sitting height, however, the Indians show substantially lower values, with children being at about the fifteenth centile until ten years in girls and 14 years in boys, while the adults are considerably below the British third centile. Other comparisons show that the Xingu are taller than Surinam Indians although of similar shoulder width. The lack of anthropometric data concerning South American Indian adults, and more especially children has been stressed. Investigations of these populations facing rapid acculturation and possible assimilation will form a baseline for the future work in public health as contacts with non-Indians increase.     

The mutation G298A-->Ala100Thr on the coding sequence of the Duffy antigen/chemokine receptor gene in non-caucasian Brazilians

Ala100Thr has been suggested to be a Caucasian genetic marker on the FY*B allele. As the Brazilian population has arisen from miscegenation among Portuguese, Africans, and Indians, this mutation could possibly be found in Euro- and Afro-Brazilians, or in Brazilian Indians. Fifty-three related individuals and a random sample of 100 subjects from the Brazilian population were investigated using the polymerase chain reaction and four restriction fragment length polymorphisms. Confirming the working hypothesis, among the related individuals three Afro-Brazilians (two of them a mother and daughter) and a woman of Amerindian descent had the Ala100Thr mutation on the FY*B allele. Five non-related Euro-Brazilians also carried the mutation. All nine individuals presented the Fy(a-b+) phenotype. We conclude that the Ala100Thr mutation can occur in populations other than Caucasians and that this mutation does not affect Duffy expression on red blood cells. Gene frequencies for this allele in the non-related individuals were in agreement with those of other populations. The Duffy frequencies of two Amerindian tribes were also investigated.     

The Seminole Indians of Florida: morphology and serology

The Seminole Indians of Florida were studied on their three reservations for blood types, red cell enzymes, serum proteins, physical measurements, and relationships. Both serologic and morphologic factors suggest their close similarity to other Indians and small amount of admixture. The Florida Seminoles are similar to Cherokee “full-bloods” in their absence of Rho and their incidence of O and M. In the presence of Di^a they are similar to other Indians, especially those of South America. While the presence of G-6-P-D A and the frequency of Hgb. S are indicative of Negro ancestry, the absence of Rho suggests that the Negro contribution must have been small. Physical traits give parallel results. Both serology and morphology further show that the Seminoles of the Dania and Big Cypress reservations are more similar to each other than to those of the Brighton reservation, in keeping with their history.     

Growth and skeletal maturation in British Columbia Indian Populations

Stature and skeletal maturation in childhood, mature stature, and calorie and protein intakes were studied in two populations of British Columbia Indians. Although mature stature was similar in both groups, one population (Anaham) showed delayed stature achieved for age and delayed skeletal maturity in childhood, compared with the other population (Ahousat). Analysis of growth data suggests that environmental factors are probably the predominant cause of the differences, which coincide with differences in nutritional status. Mean calorie intakes at Ahousat approximate or exceed the Canadian Dietary Standards, but those at Anaham are consistently below the standards for all age groups. Although mean protein intakes are well above the standards for all age groups, except teen-age girls at both reserves, they are consistently lower at Anaham than at Ahousat.     

Ethnicity and type 2 diabetes in Rio de Janeiro,Brazil, with a review of the prevalence of the disease in Amerindians

To what extent can ethnic factors contribute to the prevalence of type 2 diabetes and impaired glucose tolerance (IGT) in an urban Brazilian population? Conversely, how can environmental factors such as diet change these prevalences in a given ethnic group, in this case Brazilian Indians? To answer these questions estimates of ethnic admixture in Afro- and Euro-Brazilians from Rio de Janeiro, Brazil, were established using eight genetic systems and compared with the prevalences of these conditions obtained previously. This information was integrated with results obtained inside and outside of Brazil. The similarity of prevalences for type 2 diabetes and IGT in Afro- and Euro-Brazilians may be related to the extensive gene flow that occurred between them and to similar socioeconomic levels in the samples investigated. On the other hand, changes in the traditional diet are probably conditioning the appearance of diabetes among Brazilian and other South American Indians.     

Subtropical Interactions: Comparing Galling Insect and Host Plant Diversity in Southern Brazil and Florida

Gall-inducing insects seem to have a diversity pattern distinct from the usual latitudinal decrease in species, with more species occurring in xeric environments instead. Many questions regarding galler diversity over geographical scales remain unanswered: for example, little is known about beta diversity, and the role super host plants play in local/regional richness. Our aim was to compare galling insect and host plant diversity in different biogeographical regions, but under similar environmental conditions. We sampled short stature coastal woodlands on sandy soils of the Atlantic coast in both USA (Florida) and Brazil (Rio Grande do Sul, RS), between 25° and 30° latitude. Little-used 200-m long trails were searched during 90 min for galls; there were four trails in USA and five in Brazil. Gall functional traits (galled plant organ, gall shape and colour) proportions were not different between Florida and RS. Local galling and host plant species richness also did not differ, and neither did regional galling diversity. The beta diversity pattern, however, was distinct: sites in Florida have more similar galling faunas than sites in RS. Common diversity patterns indicate common environmental biotic (plant diversity, vegetation structure) and abiotic (climate, soil) factors might be contributing to these similar responses. As Brazilian sites are in the Atlantic forest hotspot, a high galling insect beta diversity might be caused by a higher heterogeneity at larger scales—sample-based rarefaction curves were ascending for Brazil, but not for USA. Myrtaceans were super hosts in Brazil, but not in Florida, where oaks take up this role.     

Markers of genetic variation among the Waorani Indians of the Ecuadorian Amazon headwaters

Until recently, the Waorani Indians of Ecuador's Amazon headwaters maintained a fierce resistance to all intruders into their territory, and as a result of their actions and reputations a population of 600 people controlled a very large territory (about 8,000 square miles). The isolation of the Waorani has resulted in a large linguistic and genetic distance from their neighbors. Our survey of red cell enzymes, immunoglobulin allotypes, and dermatoglyphics demonstrates that the Waorani are a highly inbred and homogeneous population. Of 18 red cell enzymes studied, the Waorani have a limited polymorphism for only 6. Only two Gm haplotypes (Gm1,2,17,21, Gm1,17,21) were found and 60% of those tested were homozygous for the Gm1,17,21 haplotype. All individuals were A2m (1) and 95% of these were homozygous. The Waorani's dermatoglyphic traits fell within the wide range found among other South American Indians with close affinity to the Ecuadorian Jivaro group. Despite the limitations of these genetic systems, they demonstrate that the Waorani share limited genetic traits with the neighboring Jivaro Indians and are isolated from other tribal populations in South America.     

Population differentiation in Crepis tectorum (Asteraceae): patterns of correlation among characters

This study examines the relationship among traits distinguishing populations of C. tectorum and the extent to which existing trait associations reflect underlying (genetic) tradeoffs. Highly consistent trait associations were found in a comparison of 52 populations representing the western part of the geographical range of the species. In addition to a tight integration of traits reflecting plant stature and inflorescence development, there were consistent links between vegetative and reproductive traits; populations characterized by individuals with large leaves and tall stems with terminal branches usually had larger heads, flowers and fruits (achenes) than those whose individuals had small leaves and a short stem branched from the base. There was a weak negative relationship between the extent of leaf dissection and plant stature; short and compact plants had more deeply lobed leaves than tall plants with terminal branches. Few of these associations were present among families representing a single population of C. tectorum , but there was remarkable similarity between the correlations at the between-population level and those obtained in two segregating F2 progenies of crosses between contrasting populations. Hence, provided that the F2 correlations have a strong genetic basis, it appears that the course of population divergence has been constrained by the underlying correlation structure, although some trait associations may also be a result of selection operating in a correlated fashion on functionally related traits, perhaps leading to linkage disequilibrium of parental traits in the first segregating generation of a cross between ecologically differentiated populations.     

Gc and transferrin isoelectrofocusing subtypes among Brazilian Indians

A total of 397 persons living in six villages of three Brazilian Indian tribes were studied in relation to the Gc subtypes. The corresponding gene frequencies are more similar between the Gorotire and Caingang than between the Gorotire and the Krahó, despite the considerable geographical distance that separates the villages of these two first tribes and their lignuistic differentiation. An uncommon variant pattern (1C7) was observed in eight Gorotire Indians; it had been described for the first time in a Tibetan sample, furnishing additional evidence on the Asiatic origin of these Indians. The distinct Gc subtype frequencies observed in our main ethnic groups provide an important new tool for anthropological analyses. Tf subtypes were studied among the Caingang only. The frequencies of Tf^C1 and Tf^C2 are similar to those obtained by other researchers in Hessen, Germany.     

Child height and intergenerational transmission of health: Evidence from ethnic Indians in England

A large literature documents a widespread prevalence of small stature among Indian children as well as adults. We show that a height gap relative to a richer population such as whites in England also exists, although substantially reduced, among adult immigrants of Indian ethnicity in England. This is despite positive height selection into migration, demonstrated by ethnic Indian adults in England being on average 6–7 cm taller than in India. However, the difference between natives and ethnic Indians in England disappears among their younger sons and daughters, although it re-appears among adolescents. We estimate that, conditional on age, gender and parental height, ethnic Indian children of age 2–4 in England are 6–8% taller than in India. Such degree of catch up in one generation is remarkable, also because in England children of ethnic Indians have much smaller birthweight than whites, by about 0.4 kg on average.     

Convergent evolution of gigantism in the flora of an isolated archipelago

Animals often evolve conspicuous differences in body size after colonising isolated islands. However, far less is known about repeated patterns in the evolution of plant size on islands. We tested for convergent evolution of leaf area, seed size and plant stature in the flora of the Chatham Islands (i.e. Rēkohu), which are located 700 km off the east coast of New Zealand. First, we measured leaf area, seed size and plant stature from populations of 22 plant taxa on the Chatham Islands. These data were then compared to analogous measurements from their sister taxa on the mainland to test for evidence of island gigantism, and whether size changes differ between leaves, seeds and stature. Second, we collated data from the literature to test whether size changes in endemic taxa differed among plant growth forms or were correlated with divergence times. Results showed that all three plant traits tended to increase in size on the Chatham Islands. However, field data showed that size increases tended to be more consistent in seeds and leaves than in stature. Data from the literature indicated that size increases also differed among growth forms. Herbaceous species showed the strongest evidence of gigantism, followed by woody plants, while graminoids showed a weak trend towards dwarfism. Insular size increases in seeds and leaves were also positively related to divergence times, indicating that taxa which have resided on the Chatham Islands for longer periods show stronger evidence of gigantism than taxa which arrived more recently. Overall results illustrate that gigantism is a hallmark of the Chatham Island flora, providing a remarkable example of convergent evolution.     

Living conditions and growth of maya indian and non-maya boys from yucatan in 1993 in comparison with other studies

The purpose of this study was to characterize the biological status and living conditions of boys inhabiting the northern part of Merida. Studies were conduoted in summer 1993, in several secondary schools in the northern part of the Merida, capitol of Yucatan, Mexico. The material consisted of biological measurements of 497 boys aged from 12 to 17 years. Also parents of these children were interviewed. Mothers (497) aged from 28 to 60 years (40 on the average) and fathers (495) aged from 30 to 62 years. Values of biological characteristics were calculated for the whole material, and also separately for the families in which both parents were Maya Indians, Non-Mayas and mixed. The differences between Mixed and Non-Mayas were distinct in stature, trunk length, upper extremity length, head length, head circumference, hips breadth index, cephalic and frontal indices, thus, mainly in body size and the head and face form. Differences between Mayas and Non-Mayas were distinct in the most measures: direct measurements ofbody weight and height, trunk and both extremities length, shoulder breadth, head length, face and nose breadth, head, waist and hips circumferences (which did not show differences between two other groups as a direct measure) and triceps skinfold thickness. The differences were also found in some indices (cephalic, frontal and face) and this probably has a non-adaptive character. The difFerences in other body proportions, which could be rather easy adjustable in the meaning on ontogenetic development were not found. The constitutional differences were observed in stature, arm fatfold and hip breadth. Body proportions were under the strong influence of living conditions and this probably caused the lack of difFerences between 3 ethnic groups. The contemporary Maya boys in comparison with the Steggerda data (1941) were on average 10 cm taller, more plumb by 10 units of BMI, and had more rounded heads. Head, which is under a strong genetic control and has more conservative character showed differences between Maya and Mixed groups versus Non-Mayas.     

Which Extent is Plasticity to Light Involved in the Ecotypic Differentiation of a Tree Species from Savanna and Forest?

Light intensity and heterogeneity are some of the main environmental factors that differ between forest and savanna habitats, and plant species from these habitats form distinct functional types. In this study, we tested the hypothesis that not only differences in morphological and physiological traits but also phenotypic plasticity in response to light are involved in adaptation to forest and savanna habitats by investigating ecotypic differentiation between populations of Plathymenia reticulata (Leguminosae: Mimosoideae), a tree from the Brazilian Atlantic Forest and the Brazilian Cerrado (savanna). Seeds from four natural populations (one from each biome core area and two from ecotonal regions) were grown in a common garden with four light treatments. Fifteen morphological and physiological characteristics were evaluated until individuals reached 6 mo old. Comparisons among populations showed differences for seven traits in at least one light treatment. These differences pointed to local adaptation to different biomes. Populations showed different levels of phenotypic plasticity in response to light in seven traits. Higher plasticity was found either in the forest core population or ecotonal populations; lower values were found in the cerrado core population. Lower plasticity in the cerrado population emphasizes the stress resistant syndrome, as lower plasticity is probably advantageous in a habitat where a conservative resource use is crucial. Higher plasticity in forest individuals suggests higher ability in exploiting the light heterogeneity in this habitat. Also, higher plasticity in ecotonal populations can be important to ensure the maintenance of P. reticulata in these temporally and spatially dynamic areas. Abstract in Portugese is available at http://www.blackwell‐synergy.com/loi/btp .     

Natural selection is not related to reduced body size in a rural subsistence agricultural community in southern Mexico

Adult Zapotecs are among the shortest Indians in Mexico. This study investigated whether reduced body size was an effect of genetic selection or a developmental effect of very poor nutrition and health. Fertility, offspring survival, and offspring prereproductive mortality were regressed on stature and weight of 205 multiparous adults (ages 20 to 72). The statistical analyses suggest that the exceptionally short stature of Zapotec Indians in this community is due to poor environmental conditions and not to genetic selection or adaptation.     

Catawba Indians: morphology, genetics, and history

The Catawba Indians of South Carolina appear to be descendants of the once flourishing Siouan tribe now admixed primarily with Whites of the area. Study of physical traits and blood types was made in 1962 at the time they terminated reservation status. The data permit comparisions with other populations and an estimation of the genetic contribution of presumed parental populations to the hybrid. Skeletal remains of Siouan Indians from archeological sites in the area provide a basis for morphological comparisons. Similar ties of the Catawba to the Indian Knoll people of Kentucky and to the Occaneechi people of early historic times are noted. Results of blood typings of these ancient bones also enable some tentative serological comparisons with the present day Catawba Indians. Certain unusual factors in the history of the present population have affected their isolation and admixture, and this interaction of culture and biology is explored.     

Growth and Body Mass Index of Brazilians Ages 9 Through 17 Years

Obesity during adolescence is considered a strong predictor of adult obesity, and obesity and overweight have been increasing among Brazilian adults. To gauge the relative frequency of overweight among adolescents in Brazil, we compared the distributions of body mass index (kg/m²) and stature in national population based samples of the U.S. and Brazil. U.S. adolescents were on average about 10 cm taller than Brazilians, although growth spurts occurred at the same age for both populations. Brazilian adolescents were leaner than their U.S. counterparts. This difference was reduced among girls in the postpubertal period. At age 17 years, U.S. boys were about 10 kg heavier than Brazilian boys, but the difference among girls was only 2 kg. In families above the poverty level in the more developed South region, body mass index distribution for boys was closer to that of the U.S., and older girls tended to have higher body mass index than U.S. girls. Within Brazil, body mass index varied by ethnicity with Mulattos, but not Blacks, of both sexes having lower body mass index than Whites of the same age. Urban adolescents had higher body mass index than those living in rural areas. In general, the patterns seen among Brazilian adults were found among children. Among girls, in particular, overweight has become an identifiable problem during adolescence.     

Estimation of stature from long bones utilizing the line of organic correlation

Estimation of stature from skeletal measurements is of great interest in some studies, e.g. in forensic anthropology, where victims have to be identified. A problem occurring in practice is that the individual whose stature has to be assessed is in general from an unknown population. Alternatives to ordinary least squares regression are discussed. Application of available information about stature/long bone proportions leads to a general proposal called thethe weighted line of organic correlation, which is fitted to a wide range of populations. The effects of sex and race upon this line are practically negligible. These properties makes it suitable for use not only for forensic purposes, but also for the estimation of stature based on skeletons or skeletal populations from the past.