Austronesian genetic signature in East African Madagascar and Polynesia

Abstract

The dispersal of the Austronesian language family from Southeast Asia represents the last major diaspora leading to the peopling of Oceania to the East and the Indian Ocean to the West. Several theories have been proposed to explain the current locations, and the linguistic and cultural diversity of Austronesian populations. However, the existing data do not support unequivocally any given migrational scenario. In the current study, the genetic profile of 15 autosomal STR loci is reported for the first time for two populations from opposite poles of the Austronesian range, Madagascar at the West and Tonga to the East. These collections are also compared to geographically targeted reference populations of Austronesian descent in order to investigate their current relationships and potential source population(s) within Southeast Asia. Our results indicate that while Madagascar derives 66.3% of its genetic makeup from Africa, a clear connection between the East African island and Southeast Asia can be discerned. The data suggest that although geographic location has influenced the phylogenetic relationships between Austronesian populations, a genetic connection that binds them beyond geographical divides is apparent.

Increased Y-chromosome resolution of haplogroup O suggests genetic ties between the Ami aborigines of Taiwan and the Polynesian Islands of Samoa and Tonga

“…The admixture results reflect strong Melanesian influence in Fiji. Thus, using O1a as a marker for the later stages of the Austronesian expansion into Polynesia, given the paucity and the low frequencies at which it is found throughout the Pacific, is inappropriate and would provide fallacious support for the notion that Polynesian populations contain little or no genetic influences from Taiwan, which would contradict previously demonstrated genetic connections between these groups (Hagelberg et al, 1999;Kayser et al, 2003Kayser et al, , 2006Kayser et al, , 2008Lum, 1998;Melton et al, 1995;Regueiro et al, 2008). It is possible that the relative absence of haplogroup O1a in Polynesia and the Pacific may have been the result of the haplogroup being lost during the repeated bottleneck events experienced by the Austronesian migrants.…”

“…Examination of 15 hypervariable autosomal STR loci by Regueiro et al (2008) indicated that approximately 76% and 24% of the Samoan and 65% and 35% of the Tongan autosomal gene pools are of Southeast Asian and Melanesian descent, respectively. These proportions are similar to those determined by Kayser et al (2008) using a set of 327 autosomal STR markers, who found that East Asians and Melanesians contributed 79% and 21%, respectively, to Polynesian groups.…”

Genetic diversity on the Comoros Islands shows early seafaring as major determinant of human biocultural evolution in the Western Indian Ocean

“…1,3,4 Clear genetic evidence for the SEA influence has been found on neighbouring Madagascar. [5][6][7][8] On the basis of Y chromosome and mitochondrial variation, ethnic groups with the strongest SEA biocultural features in Madagascar were estimated to have approximately 50% SEA ancestry. 5,8 In contrast to Madagascar where the language, Malagasy, is an Austronesian language with origins in SEA, the languages spoken on the Comoros are of Bantu origin.…”

Genome-wide evidence of Austronesian–Bantu admixture and cultural reversion in a hunter-gatherer group of Madagascar

“…In contrast, 90% of Malagasy vocabulary belongs to the Barito (6) or other subgroups of Austronesian languages of Island Southeast Asia (7)(8)(9). Although being less specific, genetic studies have generally confirmed the dual ancestry of the Malagasy population (10)(11)(12)(13)(14).…”