Reconstructing the origin of the Lapita Cultural Complex: mtDNA analyses of East Sepik Province, PNG

Abstract

The colonization of Oceania occurred in two waves. By 32,000 BP, humans had reached New Guinea and settled all intervisible islands east to the Solomon Islands. Around 3,500 BP, a distinct intrusive group from Southeast Asia reached coastal New Guinea, integrated their components with indigenous resources, and gave rise to the Lapita Cultural Complex. Within 2,500 years, Lapita and its descendant cultures colonized the Pacific. To uncover the origin of the Lapita Cultural Complex, we analyzed the hypervariable region I of the mitochondrial deoxyribonucleic acid (mtDNA) in 219 individuals from eight East Sepik Province villages: two villages in each of four environmental zones. Same-zone villages spoke different languages: one Austronesian and three Papuan (Arapesh, Abelam, and Boiken). Our analysis examined whether language or geography better predicted gene flow. In general, language better predicted genetic affinities. Boiken villages across all four zones showed no significant genetic difference (F ST P value [ 0.05). In contrast, the Austronesian village was significantly different to most other villages (P \ 0.05). Only the mountains and coast showed zonal gene flow (P [ 0.05). We interpret the data to reflect limited gene flow inland by Austronesians overshadowed by a regional displacement by inland Boiken speakers migrating seaward. These results are consistent with oral histories and ethnographic accounts.

Characterization of population structure from the mitochondrial DNA vis‐à‐vis language and geography in Papua New Guinea

“…Some previous studies have suggested limited contact between Austronesian-speaking populations and Papuan-speaking populations (e.g. Vilar et al, 2008), but our study proposes that interaction between people between different language families occurred more frequently than previously thought.…”

“…The two haplotypes assigned to B4 were confirmed by the 9-bp deletion at the COII/tRNA Lys intergenic region. One B4 haplotype (RW248) shows the same mutations in HV1 that are also found in the East Sepik of New Guinea (Vilar et al, 2008). One haplotype from Jama-Sepik and one from Dreikikir are unassigned.…”

“…Samples were also screened for the intergenic COII/tRNA Lys 9-bp deletion. Additional sequences from Papua New Guinea and Oceania were compiled using data from the literature Merriwether et al, 2005;Vilar et al, 2008). We only used the hypervariable region 1 (HV1) sequences for this broader comparison (np 16,019-16,351).…”

Human genetics of the Kula Ring: Y-chromosome and mitochondrial DNA variation in the Massim of Papua New Guinea

“…1,2 Previous studies have addressed human genetic variation in Oceania, particularly Polynesia, [3][4][5][6][7][8] mainland New Guinea [9][10][11][12][13] and Island Melanesia. [14][15][16][17][18] One area of Near Oceania (NO) yet understudied from a human genetic perspective is the island region off the southeastern tip of New Guinea (Figure 1).…”

Peopling of the Pacific: A Holistic Anthropological Perspective

“…. Polynesian ancestors originated from East Asia but genetically mixed with Melanesians before colonizing the Pacific" (Kayser et al 2008(Kayser et al , p. 1362Vilar et al 2008). A period of sustained gene flow between ancestral Polynesian and Melanesian populations is also evidenced by the presence of an α-thalassemia deletion, which confers resistance to malaria, and must have been transferred to the ancestral Polynesian populations in Near Oceania before their dispersal to Remote Oceania, where malaria is generally absent (Hill et al 1985, Martinson 1996.…”