The population structure of an Amerindian tribe, the Yanomama.
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Age Factors↗
Biomedical subjects
J V Neel
Publications and source records attributed to J V Neel.
Rare variants, private polymorphisms, and locus heterozygosity in Amerindian populations.
The results of 21,103 electrophoretic typings distributed across 28 polypeptides in members of 12 Amerindian tribes are reported, and the accumulated results of electrophoretic studies on these same polypeptides in 21 Amerindian tribes are then analyzed. Thus far 11 'private' polymorphisms have been identified in these tribes. When the tribal samples are combined and traits achieving polymorphic proportions in the total sample excluded from consideration, the average frequency of rare variants is 2.8 per 1,000 determinations. For a subset of 23 of these polypeptides also studied in Caucasians and Japanese, variant frequencies per 1,000 determinations are: Indians, 2.2; Caucasians (British), 1.6; and Japanese, 1.5. Average locus heterogeneity for these polypeptides (based on rare variants plus polymorphisms) is: Indians, .049; Caucasians, .078; and Japanese, .077. A higher proportion of loci are monomorphic within tribes than within civilized urban populations. It is argued that for inferences concerning the forces maintaining genetic variability within populations, studies on samples from tribespeople are much more appropriate than studies on samples from civilized urban populations.
Blood Proteins↗
The National Academy of Sciences--National Research Council Twin Registry: ten years of operation.
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Anthropometry↗
Unusual blood genetic characteristics among the Ayoreo Indians of Bolivia and Paraguay.
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Blood Group Antigens↗
The genetics of juvenile-onset-type diabetes mellitus.
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Child↗
Genetic studies of the Macushi and Wapishana Indians. II. Data on 12 genetic polymorphisms of the red cell and serum proteins: gene flor between the tribes.
Blood samples from 509 Macushi (3 villages) and 623 Wapishana (11 villages) of Northern Brasil and Southern Guyana have been analyzed with respect to the phenotype and gene frequencies at the following 12 polymorphic loci: ABO, Kell-Cellano, MNSs, Rh, P, Duffy, Kidd, Diego, Lewis, Group-specific component, and the immunoglobulin allotypes of the Gm and Inv systems. The data suggest that 5-6% of the Wapishana gene pool is derived from non-Indians but only 1-2% of the Macushi. Inter- and intratribal genetic distances between villages are calculated for these data in an effort to understand gene flow between the tribes and to account for the unusual distribution of a newly-discovered genetic polymorphism of erythrocyte esterase A thus far limited to these 2 tribes (Neel et al., 1977). The data are puzzling and consistent with the possibility that both the Carib-speaking Macushi and the Arawak-speaking Wapishana have derived the esterase A allele in question from some third group now extinct or thus far undiscovered. Intertribal genetic distances based on gene frequencies at 6 loci are derived for 20 Amerindian tribes (including these 2); the "central" position of these 2 tribes can in part be explained by the active migration matrix connecting them.
ABO Blood-Group System↗
Genetic studies of the Macushi and Wapishana Indians. I. Rare genetic variants and a "private polymorphism' of esterase A.
Blood samples from 509 Macushi and 623 Wapishana Amerindians of of Northern Brazil and Southern Guyana have been analyzed with reference to the occurrence of rare variants and genetic polymorphisms of the following 25 systems: (i) Erythrocyte enzymes: acid phosphatase-1, adenosine deaminase, adenylate kinase-k, carbonic anhydrase-1, carbonic anhydrase-2, esterase A1,2,3, esterase D, galactose-1-phosphate uridyltransferase, isocitrate dehydrogenase, lactate dehydrogenase, malate dehydrogenase, nucleoside phosphorylase, peptidase A, peptidase B, phosphoglucomutase 1, phosphoglucomutase 2, phosphogluconate dehydrogenase, phosphohexoseisomerase, triosephosphate isomerase and (ii) Serum proteins: albumin, ceruloplasmin, haptoglobin, hemoglobin A2 and transferrin. Fifteen different rare variants were detected, involving 11 of these systems. In addition, a previously undescribed variant of ESA 1,2,3 which achieves polymorphic proportions in both these tribes is described. Excluding this variant, the frequency of rare variants is 1.1/1000 in 12510 determinations in the Macushi and 4.7/1000 in 15396 determinations in the Wapishana. The ESA 1,2,3 polymorphism was not observed in 382 Makiritare, 232 Yanomama, 146 Piaroa, 404 Cayapo, 190 Kraho and 112 Moro. Irregularities in the intratribal distribution of this polymorphism in the Macushi and Wapishana render a decision as to the tribe of origin impossible at present. Gene frequencies are also given for previously described polymorphisms of 5 systems: haptoglobin, phosphoglucomutase 1, erythrocyte acid phosphatase, esterase D, and galactose-1-phosphate-uridyl-transferase.
Blood Proteins↗
Health and disease in unacculturated Amerindian populations.
The stereotype of uncontacted tribal populations is that they must reproduce at near capacity to maintain or slightly increase their numbers. This paper argues that the health of minimally contacted Amerindians, as judged by the results of physical examinations and life tables for the Yanomama of Southern Venezuela and Northern Brazil, is relatively good, with population control a feature of the Indian culture. It is further argued that the usual deterioration in health with contacts with western culture probably does not result so much from special innate susceptibilities to certain epidemic diseases and to the diets and 'stresses' of civilization as from the epidemiological characteristics of newly contacted peoples.
Acculturation↗
Intra and intertribal genetic variation within a linguistic group: the Ge-speaking indians of Brazil.
A total of 562 individuals living in four villages of two Brazilian Indian tribes (Cayapo and Krahó) was studied in relation to blood groups ABO, MNSs, , Rh, Lewis, Duffy, Kidd and Diego; haptoglobin, Gc, acid phosphatase and phosphoglucomutase types. These results were compared with those obtained previously among the Xavante, and the inhabitants of three other Cayapo villages, all of whom speak Ge languages; the ranges in gene frequencies observed in a representative series of South American Indians from all over the continent were also compiled. The Ge Indians are characterized by low frequencies of RZ, medium frequencies of R1, R2, R0, or r, Jka and PGM1/1, and high frequencies of Gc2 and ACPA when compared with other South American tribes. Genetic distance analyses based on six loci indicate that the intratribal variability observed among Cayapo is of the same order of magnitude as those obtained among the Xavante and Krahó, being much less pronounced than those observed among the Yanomama and Makiritare. The intertribal differences within this linguistic group are much less pronounced than those encountered among tribes that speak more differentiated languages.
Acid Phosphatase↗
Inbreeding estimation from population data: models, procedures and implications.
Four different estimation procedures for models of population structure are compared. The parameters of the models are shown to be equivalent and, in most cases, easily expressed in terms of the parameters WRIGHT calls "F-statistics." We have estimated the parameters of each of these models with data on nine codominant allele pairs in 47 Yanomama villages, and we find that the different estimators for a given parameter all yield more or less equivalent results. F-statistics are often equated to inbreeding coefficients that are definid as the probability of identity by descent from alleles taken to be unique in some founding population. However, we are led to infer from computer simulation and general historical considerations that all estimates from genotype frequencies greatly underestimate the inbreeding coefficient for alleles in the founding population of American Indians in the western hemisphere. We surmise that in the highly subdivided tribal populations which prevailed until the recent advent of civilization, the probability of identity by descent for homologous alleles was roughly 0.5. We consider some consequences of working with the customary, much lower, estimates--0.005 to 0.01--if, on the time scale of human evolution, these represent only a very recent departure from the inbreeding intensity that prevailed before civilization.
Alleles↗
Multivariate analysis of gametic disequilibrium in the Yanomama.
The gametic disequilibria between all possible pairs of loci were examined for a set of eight codominant loci in each of fifty Yanomama villages, using a multivariate correlation analysis which reduces the results to a single measure of departure from multiple-locus-gametic equilibrium. Thirty-two of the fifty villages departed significantly from multiple-locus gametic equilibrium. The largest contributions to the departure from multiple-locus equilibrium were due to the disequilibria between MN and Ss and between Rh(Cc) and Rh(Ee), indicating the effects of tight linkage. After removing the effects of these obvious sources of disequilibrium, sixteen of the fifty villages still remained significantly out of equilibrium. The disequilibrium between any particular pair of loci was highly erratic from village to village, and (with the exception of the MN-Ss and Cc-Ee disequilibria) averaged out very close to zero overall, suggesting a lack of systematic forces (epistatic selection). The departure from equilibrium in any one village is in excess of that expected from random sampling alone, and is attributed primarily to the fission-fusion mode of village formation operative in the Yanomama and the fact that a single village consists of a few extended lineages. Village allele frequencies are highly correlated across loci, and most of the non-independence is accounted for by large correlations in the average allelic frequencies of different loci for related villages. It is suggested that these correlations also are due to territorial expansion and population growth. For the tribe as a whole, all but the tightly linked markers of the MNSs and Rh complexes are approximately uncorrelated, and large departures from multiple-locus Hardy-Weinberg expectation are primarily due to substantial Wahlund variance within the tribe. There is no need to postulate a role for selection in these disequilibria.
Alleles↗
The frequency in Japanese of genetic variants of 22 proteins. III. Phosphoglucomutase-1, phosphoglucomutase-2, 6-phosphogluconate dehydrogenase, adenylate kinase, and adenosine deaminase.
Five enzyme systems, PGM1, PGM2, ADA, 6-PGD and AK, were examined by electrophoresis in over 4000 samples from Hiroshima and Nagasaki for the frequencies of common and rare variants. In the PGM1 system, the PGM2(1) allele and PGM7(1) allele were found in polymorphic proportions, In addition, five kinds of slow variants and three types of fast variants of PGM1 were detected. The PGM3(1)NGS1 allele was found in five individuals from Nagasaki, but was not observed in samples from Hiroshima. There were no variants of PGM2. Three kinds of fast variants of 6-PGD were detected. No variation in AK was observed. There were no rare variants of ADA. The 6-PGDc allele had a frequency of 0.084 in Hiroshima and 0.093 in Nagasaki, and the ADA2 allele frequencies of 0.025 in Hiroshima and 0.032 in Nagasaki.
Adenosine Deaminase↗
The frequency in Japanese of genetic variants of 22 proteins II. Carbonic anhydrase I and II, lactate dehydrogenase, malate dehydrogenase, nucleoside phosphorylase, triose phosphate isomerase, haemoglobin A and haemoglobin A2.
This paper presents the results of a survey of Japanese for electrophoretic variants of CA I, CA II, LDH, MDH, TPI, NP, HB A and A2, the number of determinations per system ranging from 738 to 4029. Four similar variants of CA I (designed CA IHIR1), one of LDH (designated LDHNGS1), one of MDH (designated MDHS 7HIR1), two of HB A (one a reascertainment of HB Hijiyama, the other not characterized), and one characterized by the absence of HB A2 (delta-thalassaemia) were observed and are described. The CA IHIR1, LDHNAG1 and MDHS 2HIR1 variants have not been previously observed in Japan. No electrophoretic variants were found in the TPI and NP systems.
Adult↗
Plaque, caries, periodontal diseases, and acculturation among Yanomamö Indians, Venezuela.
The number of DM and d teeth and surfaces was recorded for 220 Yanomamö Indians from three groups of villages with different degrees of contact with Western culture. Specimens of plaque were taken from the teeth, transported in a holding solution, cultured, and examined for specific oral streptococci. In addition, the periodontal health and oral hygiene of one group of villagers were assessed using the Russell PI and the Greene & Vermillions OHIS. Caries experience among the Yanomamö was shown to be positively associated with exposure to Western culture. S. mutans was recovered with about the same frequency from specimens taken from the teeth of Indians living at all three village locations. However, the presence of S. mutans alone did not account for the disparity in dental caries scores. The examinees had abundant and persistent accumulations of soft deposits on their teeth accompanied by markedly inflamed gingival tissues. However, periodontal pockets and loss of appreciable amounts of bone did not appear as early in life nor were they as severe as reported for some other populations which practice little oral hygiene. Those disparities in the distribution of plaque-induced oral diseases between Western populations and the Yanomamö warrant further study.
Acculturation↗
The frequency in Japanese of genetic variants of 22 proteins. I. Albumin, ceruloplasmin, haptoglobin, and transferrin.
This paper presents the results of an electrophoretic survey of approximately 4000 individuals from the cities of Hiroshima and Nagasaki, Japan, for four serum proteins: albumin, ceruloplasmin, haptoglobin and transferrin. The haptoglobin gene frequencies obtained for the HP1-HP2 polymorphism are in agreement with earlier reports. Rare electrophoretic variants of albumin, ceruloplasmin and haptoglobin occur with frequencies of 2-48, 0-50 and 0-58 per 1000 determinations, respectively. The noteworthy finding of 8 distinct transferrin variants in these populations, with a combined frequency of 20-90 per 1000 determinations, is also presented. Four of these variants (Dchi, B1, B3, and DHIR2 which corresponds electrophoretically to D4) have been reported in other populations in Japan, but the other five have not previously been differentiated.
Blood Protein Electrophoresis↗
Two more "private" polymorphisms of Amerindian tribes: LDHb GUA-1 and ACP1 B GUA-1 in the Guaymi in Panama.
A survey of Guaymi Indians of Panama for the occurrence of genetic variants of 25 proteins of the erythrocytes and sera have revealed, in addition to seven well-known genetic polymorphisms, four rare variants and two "private polymorphisms," the latter involving erythrocyte acid phosphatase and lactate dehydrogenase. The significance of such private polymorphisms in tribal populations to the interpretation of rare variants in civilized populations is emphasized.
ABO Blood-Group System↗
Genetic structure of a tribal population, the Yanomama Indians. XIII. Dental microdifferentiation.
Data are presented on the frequency of the following eight dental traits in 635 Yanomama and 65 Makiritare Indians: upper central incisor rotation or winging, shoveling of maxillary incisors, maxillary molar hypocone reduction, Carabelli's trait, mandibular molar cusp number, mandibular molar cusp pattern rotation of second lower premolar, and pattern of second lower premolar cusps. Yanomama dentition is unusual in the high frequency of six cusps on the mandibular molars. There is marked dental microdifferentiation between villages; significant agreement was observed between a matrix of pairwise "dental distances" based on six morphological traits and corresponding matrices based on 11 genetic systems and on geographic location.
Brazil↗
The genetic structure of a tribal population, the Yanomama Indians. XIV. Clines and their interpretation.
The Yanomama Indians are a South American tribe distributed over an irregular area approximately 200 X 300 miles. The gene frequencies observed at 12 loci in 47 villages within this area have been analyzed for the occurrence of clines. Apparently significant clines are observed for alleles of the Rh, MNSs, Kidd, Gm, Inv and serum albumin system. Available data concerning recent tribal expansion and admixture permit a tentative analysis of the causes of these clines. Although the action of selection cannot be rigorously excluded, it seems unlikely to be the major couse. Admixture with surrounding tribes plays a role which can be quantified because of the fortuitous cicumstance of two genetic markers for admixture. It is suggested that an important factor in the origin of these clines is the manner in which the tribe has recently expanded through successive village fissionings and a predominantly centrifugal pattern of village migration.
Alleles↗