Pygmy Populations Research Articles

Perinatal practices among the Efe' (Pygmies) and Walese of Zaire

To reconstruct modern human evolutionary history and identify loci that have shaped hunter-gatherer adaptation, we sequenced the whole genomes of five individuals in each of three different hunter-gatherer populations at >60× coverage: Pygmies from Cameroon and Khoesan-speaking Hadza and Sandawe from Tanzania. We identify 13.4 million variants, substantially increasing the set of known human variation. We found evidence of archaic introgression in all three populations, and the distribution of time to most recent common ancestors from these regions is similar to that observed for introgressed regions in Europeans. Additionally, we identify numerous loci that harbor signatures of local adaptation, including genes involved in immunity, metabolism, olfactory and taste perception, reproduction, and wound healing. Within the Pygmy population, we identify multiple highly differentiated loci that play a role in growth and anterior pituitary function and are associated with height.

Ecology and Population Dynamics of the Pygmy Marmoset, Cebuella pygmaea

The pygmy marmoset population of a 3-km2 sample area of Amazonian lowland forest was censused and monitored intensively between September 1976 and January 1978. Floodplain forest constituted the habitat of Cebuella and supported a population density of 51.5 independently locomoting individuals (ILI) per square kilometer. The highest population concentration occurred along the edges of the river, where the density reached 274 ILI per km2. Adults comprised about one half of the total population. About 83% of the population lived in stable troops; the remaining 17% was made up by incipiently associated pairs and solitary individuals. Stable troops were made up of 1 breeding female, her mate, and her maturing offspring of up to four successive litters. Moreover, some troops contained 1-2 additional adult members. Troop size ranged from 2 to 9 ILI, with a modal size of 6 ILI. The births showed two annual peaks and the interbirth intervals ranged between 5 and 7 months. Infant survival was about 67%. Exudates (sap and gums) of trees and vines, insects and arachnids constituted the principal food resources of the population. The troops occupied exclusive home ranges of 0.2-0.4 ha. Several troops changed home range sites temporarily or permanently in the course of the study.

Gc subtypes demonstrated by isoelectric focusing: further data and description of new variants among an African sample (Fula) from Senegal.

The polymorphism of the Group Specific Component (Gc) was studied in serum samples from a Fula population of Senegal (Western Africa) using isoelectric focusing in slab polyacrylamide gel followed by immunofixation. The isoelectric focusing patterns of various Gc phenotypes were compared to the patterns obtained by polyacrylamide disc electrophoresis. Besides the two subtypes,Gc 1F andGc 1S ofGc 1 and theGc Ab gene, aGc 1 variant and aGc 2 variant were discovered and namedGc 1b andGc 2b respectively. The results were compared to the data obtained in a Pygmy population. They confirmed the high degree of polymorphism of the Gc protein in African populations.

Analysis of the Gc polymorphism in human populations by isoelectrofocusing on polyacrylamide gels. Demonstration of subtypes of the Gc allele and of additional Gc variants.

For the study of the group-specific component (Gc) system, serum samples were examined by polyacrylamide gel electrophoresis and by a newly developed immunofixation isoelectrofocusing procedure. Thereby, a greater extent of polymorphic variation was revealed than was known previously. The allele Gc1 could be subdivided into the alleles Gc1F and Gc1S. The distribution of Gc1 subtypes was very different in three populations (Pygmies, Amerindians, and Pyreneans) examined. New variants of the Gc1 and Gc2 genes were also described in the Amerindians and in the Pygmy population, respectively.

PARASITISM IN CONGO PYGMIES.

SummaryA study was made on parasitic infections of a group of Pygmies from the Ituri Forest region of the Congo in conjunction with other investigations. The parasitic burden of the Pygmy population was extremely high. In general, the prevalence of all intestinal parasites was greater in the Pygmies than in other African groups examined by the same methods. Malaria, an important infection in the group, was found more frequently in children than among adults. Onchocerciasis was one of the most important diseases observed because of its high prevalence and intensity.It is concluded that parasites play an important role in the health status of Pygmies.