Melanesian Populations Research Articles

Equal susceptibility of males and females on Santa Cruz Island to the carrier state of hepatitis B surface antigen.

Various studies have shown that hepatitis B surface antigen is detected more frequently in the blood of asymptomatic males than in that of asymptomatic females. The reason for this difference might be that males are more frequently infected than females or that males more frequently become asymptomatic carriers when they are infected. The sex distribution of hepatitis B surface antigen and antibody, as measured by reversed passive hemagglutination and passive hemagglutination, was determined in a Melanesian population. The frequency of the antigen was higher among males, but the ratio of antigen to antibody was the same in both sexes. This finding indicated that the higher frequency in males was due to a higher rate of infection rather than to a greater susceptibility of the males to the chronic carrier state.

Standardization of the Epidemiologic Assessment of Periodontal Diseases: Surveys in the South Pacific

Attempts of introducing uniform techniques for the collection of statistical data on the prevalence of periodontal diseases have been made by FDI and WHO in order to arrive at valid, reproducible, and internationally comparable results. The WHO Manual of the International Classification of Diseases. Application to Dentistry offers a five digit classification of all oral diseases for statistical purposes. In contrast to morbidity statistics, epidemiological surveys must be based on adequate samples, representative for the entire population or distinct strata thereof. FDI is actually preparing guidelines for the conduct of clinical trials in periodontal diseases, comparable to those on caries incidence, indicating the proper use of indices. For the epidemiological assessment of periodontal diseases, the WHO Basic Methods (1962, 1971) have recommended the use of simple ratios of persons affected with signs of the disease. Data collected in four extensive dental surveys in Polynesian and Melanesian populations in the South Pacific served as an example to show the variety of valid information provided by these basic methods. The main results showed an early appearance of pocket formation at ages 10 to 14, preceded in a statistically significant way by calculus formation and gingivitis. A constant pattern in the sequence of attack of the various teeth by pocket formation was shown to be specific for these island populations; males were consistently more affected than females. The character of periodontal diseases prevalent among Polynesians and Melanesians was recognized to be a "dirt pyorrhea" accompanied by progressive subgingival calculus deposition and destructive periodontitis.

The occurrence of haemoglobin-J (Tongariki) and of thalassaemia on Karkar Island and the Papua New Guinea mainland.

The known α-chain variant Hb-J (Tongariki) was found to occur at relatively high frequency in several villages on the island of Karkar, about 15 km from the New Guinea mainland. The same variant was also found in an adjacent coastal region of the mainland, but not in a large number of blood samples collected in the Central Highlands. This is the third Pacific location in which Hb-J (Tongariki) has been found, and this variant may be a useful genetic marker for the study of Melanesian populations. Hb-J (Tongariki) is a ‘high-level ’ α-chain variant; its mean proportion in heterozygotes is 41 %. Three homozygotes were found in which Hb-J (Tongariki) and Hb-J 2 (α J 2 δ 2 ) were the sole major and minor constituents respectively. These findings are of interest in relation to current studies on the possible duplication of the human α-chain gene locus.

Excess males among siblings of Australian antigen carriers.

REPEATED studies have shown that Australia antigen carriers tend to group in families and there is considerable evidence that susceptibility to chronic asymptomatic infection producing Australia antigen (Au, hepatitis B antigen) is inherited as an autosomal recessive trait1–3. The occurrence of asymptomatic carriers of Au varies in different populations, ranging from 0.1 % in the United States and northern Europe to 24% in the Melanesian population of the Lau people on Malaita, as measured by immunodiffusion4. The frequency of Au carriers is relatively high in Oceania and particularly high in Melanesian populations5,6. If this trait is genetically determined, there would be a greater number of individuals who are either homozygous or heterozygous for the proposed recessive gene, Au1, in populations where the trait is common. Blumberg has suggested that these individuals may possess a selective advantage in certain environments7.

Genetic studies among the Kadar of Kerala.

A total of 213 Kadar from a number of villages in the Anamalai Hills, South India have been tested for 4 blood group, 5 serum protein and 15 enzyme systems, as well as haemoglobin. The frequencies of genes in the ABO, MN and Rh blood group systems are compatible with values reported previouslythe fourth blood group system Ina was invariant, all persons tested being In(a-). Similarly no variants were detected in the transferrin, caeruloplasmin and albumin serum protein systerns. The haptoglobin gene Hp1 had a frequency of 0.41, high for Indian populations and also the Gm-1–2allele had a high frequency. Two individuals had the rare phenotype Gm (–1, +2). Amongst the red cell enzyme systems distinctive variants were detected in the phospho-gluconate dehydrogenase, phosphoglucomutase (locus 1) and peptidase B systems. The allele PGDKadar controls an electrophoretically fast variant and examples of combinations of this allele with PGDA, PGDC and itself were observed. In the PGM (locus 1) system an allele controlling a slower than normal component was present and may be identical with the PGD61 (African) allele detected in a black African. Individuals homozygous for this allele and others heterozygous with it and the normal PGM11and PGM12alleles were present. A single person with a peptidase B variant was detected. The mobility of the variant band was indistinguishable from the Pep B 6 in Australian aboriginals. The pb allele of the acid phosphatase system accounted for nearly 90%, Calcutta-1 variants had a frequency of 3.3%, the AK2 gene frequency was only 3.3%, and only two cases of HbS were detected. All other systems were invariant. Theories concerning the origin of the possible negrito-like traits in a small number of Kadar were discussed and the present evidence was considered to support the possibility of past African negro admixture on a small scale. The postulated genetic reconstruction of the ancestral Kadar population suggests that they may have been similar to Melanesian and Australian aboriginal populations, but that this original genetic structure has been modified through incorporating genetic elements not only from black Africans but from surrounding Dravidian populations.

A second example of anti-Ge1, and some observations on Gerbich subgroups.

Abstract. A second example of anti‐Gel has been identified. The Gerbich subgrouping of certain Melanesian populations has shown that not all subjects who react weakly with anti‐Gel, 2 or anti‐Gel, 2, 3 lack Gel specificity. It is suggested that Gel, ‐2 people may exist in New Guinea.

Quantitative hair form variation in seven populations.

AbstractAlthough hair form has received much attention in the past, it has rarely been studied systematically, and never using direct curling variables. In the present study, seven groups were scored on eight variables, including four newly‐devised curling variables. These data were analyzed using univariate and multivariate techniques to give information about the population relations and mechanisms of hair form. “Racial” groups were separated using a principal components analysis. African and Melanesian populations were shown to have significantly different quantitative hair form traits, especially in regard to their regularity of curvature. The physiological, environmental, and genetic factors contributing to hair form variation are discussed.

FOLKLORE AND PLACE NAMES IN SANTA ANA, SOLOMON ISLANDS

SANTA ANA is a small coral island off the south-eastern tip of San Cristobal, in the British Solomon Island Protectorate. Its Melanesian population of some 800 is divided into two loosely organized moieties, the Atawa and the Amwea, each with its own cluster of matrilineal and exogamous clans. Associated with the Atawa moiety are Mwa (snake), Mwaroa and Pagewa (shark), which is now extinct. Gafe (crab), Garofoi (turtle), Arm (trevally), Apenawiru or Apenawaru, and Kaura (frigate bird) are associated with the Amwea. All clans are represented in each of three villages in Santa Ana. Marriages most often occur across moiety lines, and since both moieties are represented in every village what this means, in many cases, is that a husband moves a few yards away into the household of his wife and her parents. He must reside on the clan property of his wife. It is also possible to marry within the moiety except in cases where clans are paired. For example, marriages are forbidden between Gafe and Garofai clans within the Amwea moiety, and between Mwa and Mwaroa within the Atawa moiety. The children are automatically members of the mother's clan and become entitled to share and work her lands. Sons are allowed use of their mother's clan land while they are living, but at their death the land must revert to the matriclan.

A Second Example of Anti-Ge^1, and Some Observations on Gerbich Subgroups

A second example of anti-Gel has been identified. The Gerbich subgrouping of certain Melanesian populations has shown that not all subjects who react weakly with anti-Gel,2 or anti-Gel,2,3 lack Gel specificity. It is suggested that Gel,-2 people may exist in New Guinea.

A "new" blood group antigen associated with S and s.

Abstract. The serum of a Papuan blood donor contains an antibody to a previously unreported red cell antigen, provisionally called Z, and closely associated with S or s. In both European and Melanesian populations Z is more common than S, because S‐positive bloods rarely lack Z, while S‐negative bloods not uncommonly possess it. Z is inherited as a dominant character.

Heredity and morphological variation in early and late developing human teeth of the same morphological class

Analysis of the resemblance between relatives from two Melanesian populations indicated that, for each of five morphological characters scored on an earlier and a later developing member of a tooth class, the later developing tooth showed a smaller component of additive genetic variation. This finding suggests that the greater morphological variability generally observed at the distal ends of tooth classes may be due primarily to a difference between the environmental conditions experienced by earlier and later developing teeth within a morphological class. The cusp of Carabelli and groove pattern of the lower molars, on the first tooth of their respective classes, were uncorrelated and showed higher degrees of resemblance between relatives than the other three characters studied. These two characters would therefore seem to serve as relatively good and independent population discriminators.

Occurrence of heterozygotes and homozygotes for the alpha-chain haemoglobin variant Hb-J(Tongariki) in New Guinea.

THE occurrence of the haemoglobin Hb-J(Tongariki) in new locations in the New Guinea area is of interest because this α-chain variant was the first to be found in Melanesian populations. Furthermore, the high proportion of the variant in heterozygotes and the discovery of three apparently homozygous subjects with Hb-J(Tongariki) as the sole major haemoglobin are relevant to current discussion concerning the possible duplication of the human α-chain gene locus.

A ‘New’ Blood Group Antigen Associated with S and s

The serum of a Papuan blood donor contains an antibody to a previously unreported red cell antigen, provisionally called Z, and closely associated with S or s. In both European and Melanesian populations Z is more common than S, because S-positive bloods rarely lack Z, while S-negative bloods not uncommonly possess it. Z is inherited as a dominant character.

Gammaglobulin allotypes of Melanesians from Malaita and Bougainville, Solomon Islands.

AbstractData are presented on the distribution of the Gm and Inv allotypes of human IgG in samples from Melanesian populations, three from Malaita and three from Bougainville of the Solomon Islands. The Lau from Malaita are polymorphic for the phenogroup, Gm1, 2, 5, 13, 14. This phenogroup is not known to be polymorphic in any other population of the world. The Inv1 frequencies of the populations from Malaita are lower than the lowest observed in samples from Bougainville, and this may indicate an extension of the north‐south cline for Inv1 previously reported for Bougainville.Samples from Aita in the north of Bougainville and from the Nagovisi in the south confirm the existence of the north‐south cline for Inv1 in Bougainville and suggest the presence of a Gm cline.

Morphological variation and heritability in three Melanesian populations: a multivariate approach.

AbstractIn two previous papers Giles, Walsh and Bradley ('66) and Giles, Wyber and Walsh ('70) have shown that the inhabitants of three adjacent villages on the edge of the Markham Valley in New Guinea have significant heterogeneity in all blood group frequencies tested. The language, environment, culture, and ancestry of these people are essentially identical. The differences in the blood group frequencies were attributed to genetic drift and particularly to founder effect.In this paper the anthropometric data from these villages are analysed. Analysis of variance shows that 50% of the traits are significantly different. Multiple discriminant analysis demonstrates that the villages can be significantly separated morphologically. The heritability of each trait is determined using an analysis of within and among sibship variation. Traits with strong “genetic” components of variation and traits with strong “environmental” components contribute significantly to the morphological heterogeneity among the villages. Some speculations are presented on the cause of the “genetic” component of morphological variation.

Endemic autoimmunity: cold auto-agglutinins in Melanesia.

Sera from two Melanesian populations, one living at sea level and the other at 7000 feet, were examined for the incidence, strength and specificity of cold agglutinins. The cold auto‐agglutination incidence ranged from 48 to 90 per cent for the sea‐level group to 94 per cent for the highlanders. Titres of the sera ranged from 10 to 640. The specificity of the antibodies was in the main anti‐I, although four probable examples of anti‐AI, four examples of anti‐IT and two ‘non‐specific’cold agglutinins were found. Blood group A subjects in both populations had a higher incidence and titre of cold agglutinins than O subjects.The light chain types of 160 of 200 cold agglutinins tested were both k and λ, 24 were K only and 16 were λ only. Fingerprints of the H chains of six New Guinea cold agglutinins showed some peptide spots missing compared with normal IgM, but more spots were present than in a lymphoma cold agglutinin, suggesting that the cold agglutinins represented a heterogeneous population of antibodies.No obvious relationship was found between environmental factors and the occurrence of the cold agglutinins.

The size and morphology of the Nasioi dentition.

AbstractDental impressions were obtained on 240 Nasioi, a Melanesian population living on the island of Bougainville. Odontometric data are presented for both the permanent and deciduous teeth, and the former teeth are also examined morphologically. The results show that the Nasioi have large permanent teeth like other Australoid populations whereas the deciduous teeth are only of moderate size. The coefficients of variation are large in the permanent teeth compared to other populations but the sexual dimorphism in tooth size and variability is not remarkable.Morphologically, the permanent teeth of the Nasioi are characterized by a cusp number pattern, a high frequency of the Dryopithecus + pattern on the first mandibular molar, few individuals with a Cusp of Carabelli, and a moderate expression of shovelled‐shaped anterior teeth.

Haemoglobin J Tongariki (alpha-115 alanine--aspartic acid): the first new haemoglobin variant found in a Pacific (Melanesian) population.

Haemoglobin J Tongariki (alpha-115 alanine--aspartic acid): the first new haemoglobin variant found in a Pacific (Melanesian) population.

On the distribution of the Gc variant Gc Aborigine in Melanesian populations; determination of Gc-types in sera from Tongariki Island, New Hebrides.

On the distribution of the Gc variant Gc Aborigine in Melanesian populations; determination of Gc-types in sera from Tongariki Island, New Hebrides.

Motor-neuron disease in natives of New Guinea.

WITH the focuses of high incidence of motor-neuron disease now known in the Chamorro and Carolinian populations in the Mariana Islands of Micronesia1 2 3 and on the Kii Peninsula of Japan,4 it has for several years been my interest to determine whether such diseases can be found among Melanesian populations in the South Pacific. This report deals with the identification of a disease similar to amyotrophic lateral sclerosis in several areas of New Guinea, with the discovery of a large focus of unusually high incidence of motor-neuron disease clinically akin to amyotrophic lateral sclerosis, but running a very slowly progressive, prolonged . . .