The Australian Barrineans and Their Relationship to Southeast Asian Negritos: An Investigation using Mitochondrial Genomics

Abstract

The existence of a short-statured Aboriginal population in the Far North Queensland (FNQ) rainforest zone of Australia's northeast coast and Tasmania has long been an enigma in Australian anthropology. Based on their reduced stature and associated morphological traits such as tightly curled hair, Birdsell and Tindale proposed that these "Barrinean" peoples were closely related to "negrito" peoples of Southeast Asia and that their ancestors had been the original Pleistocene settlers of Sahul, eventually displaced by taller invaders. Subsequent craniometric and blood protein studies, however, have suggested an overall homogeneity of indigenous Australians, including Barrineans. To confirm this finding and determine the degree of relatedness between Barrinean people and Southeast Asian negritos, we compared indigenous Australian mitochondrial DNA (mtDNA) sequences in populations from the FNQ rainforest ecozone and Tasmania with sequences from other Australian Aboriginal populations and from Southeast Asian negrito populations (Philippines Batek and Mamanwa, and mainland Southeast Asian Jahai, Mendriq, and Batak Abstract The existence of a short-statured Aboriginal population in the Far North Queensland (FNQ) rainforest zone of Australia's northeast coast and Tasmania has long been an enigma in Australian anthropology. Based on their reduced stature and associated morphological traits such as tightly curled hair, Birdsell and Tindale proposed that these "Barrinean" peoples were closely related to "negrito" peoples of Southeast Asia and that their ancestors had been the original Pleistocene settlers of Sahul, eventually displaced by taller invaders. Subsequent craniometric and blood protein studies, however, have suggested an overall homogeneity of indigenous Australians, including Barrineans. To confirm this finding and determine the degree of relatedness between Barrinean people and Southeast Asian negritos, we compared indigenous Australian mitochondrial DNA (mtDNA) sequences in populations from the FNQ rainforest ecozone and Tasmania with sequences from other Australian Aboriginal populations and from Southeast Asian negrito populations (Philippines Batek and Mamanwa, and mainland Southeast Asian Jahai, Mendriq, and Batak). The results confirm that FNQ and Tasmanian mtDNA haplogroups cluster with those of other Australian Aboriginal populations and are only very distantly related to Southeast Asian negrito haplogroups.

Human settlement history between Sunda and Sahul: a focus on East Timor (Timor-Leste) and the Pleistocenic mtDNA diversity

“…Our age estimates also contraindicate that haplogroup P1 is old but simply did not move on [77]. Intriguingly, the singular reported Australian P1 haplotype was revealed in a Northeast Aboriginal population considered closer to SEA Natives than other Australian groups in oral history and due to anthropological traits [77] ( cf. the “negrito” ancestral connection hypothesis [31]).…”

“…Despite a singular report of the only other shared P lineage, the youngest and elsewhere predominant P1, this contradicts an origin of haplogroup P in central/southern Sahul (Australia) followed by (back-)migrations to northern Sahul (NG). Rather it favours a southward colonization prior to ~36 kya, when P1 developed, and little later north–south exchange even though a landbridge existed until ~8 kya [25,34,44,53,69,75-77]. Developing this scenario further, the more recent P clades, such as P1, would have arisen later during an “incubation” stage in northern Sahul from root P* mtDNA carriers left behind.…”

“…To assess the distribution of selected marker mtDNA haplogroups, frequency values in surrounding populations were collected from published records after phylogenetic inspection [3,5,17,24,28-30,34,40,41,44,45,48,52,53,55,57-69,75-77,80,86,115,116,128-141]. Data were mostly restricted and sample sizes often very small.…”

Carriers of mitochondrial DNA macrohaplogroup R colonized Eurasia and Australasia from a southeast Asia core area

“…Although younger, the star-like radiation of P2 in New Guinea (33,5 ± 1.2 kya) extended east and westwards to adjacent islands, with indigenous branches identified in Melanesia [106] and East Timor [114], and more erratic detections beyond both sides (Additional file 1: Table S4). The presence of isolated and derived P1d1 haplotypes in Australian Barrineans [115], in the Philippines [103], and in Malaysia [116], could reflect more recent, even historic contacts. Finally, we have the expansion of P2 (18.6 ± 3.9), a young New Guinean lineage that is a sister branch of the very much evolved P10 Philippine lineage (Additional file 2: Figure S2).…”

Hunter–gatherer genomics: evolutionary insights and ethical considerations

“…One of the most striking examples of environment-specific human body shape variation is the “pygmy phenotype,” or small adult body size (e.g., average adult male stature <155 cm), a characteristic common to hunter-gatherer populations inhabiting tropical rainforests in Africa [20], Asia [19], and Oceania [31,32]. A number of scholars have hypothesized that this phenotype represents an ecological adaptation to the challenging rainforest habitat, potentially providing an evolutionary advantage by reducing metabolic demands in a calorically impoverished environment, easing demands of thermoregulation, improving mobility in the dense undergrowth and for climbing trees, speeding life histories to increase reproductive potential for individual with a high disease burden, or some combination thereof [4,33,34].…”