What is Back?
The
Negrito are several ethnic groups who inhabit isolated parts of
Southeast Asia. Their current populations include
Andamanese peoples of the
Andaman Islands,
Semang peoples of
Malaysia, the
Mani of
Thailand, and the
Aeta,
Agta, Ati, and 30 other groups of the
Philippines.
The Negrito peoples show strong physical similarities with some African populations, but are genetically closer to south-east
Asian populations. They may be descended from ancient Australoid-Melanesian settlers of Southeast Asia, or represent an early split from the southern coast migrants from
Africa.
The appropriateness of using the label 'Negrito' to bundle together peoples of different ethnicity based on similarities in stature and complexion has been challenged.
Some studies have suggested that each group should be considered separately, as the genetic evidence refutes the notion of a specific shared ancestry between the "Negrito" groups of the Andaman Islands, the
Malay Peninsula, and the Philippines
We have, however, recently investigated the position in the global mtDNA phylogeny of complete genome sequences of eight haplogroups found primarily in the Malay Peninsula, showing that most of them branch directly from the
Eurasian mtDNA ancestor lineages ~60,
000 years ago and are indigenous and unique to the Peninsula (Macaulay et al.
2005)
Current genetic evidence is beginning to highlight more recent relationships between negrito populations and other, non-negrito populations in the same region, while maintaining some evidence for deeper genetic roots of these populations (Barik et al. 2008; Chaubey and
Endicott this issue). These deep lineages may not reflect a common ancestry concurrent with the dispersal out of Africa, as predicted by the negrito hypothesis, but a degree of long-term genetic isolation from neighboring populations. The first study to integrate genotype and phenotype data of a negrito population (Migliano et al. this issue) suggests that, based on genetic variation, the Aeta,
Batak, and Agta cluster with other
South Asian populations and that their small body size evolved independently of other pygmy populations in Africa or
Papua New Guinea.
Four
Y chromosome haplogroups
C, D, O and N, accounted for more than 90% of the
East Asian Y chromosomes, are suggested to have
Southeast Asian origins, carried by three waves of migrations.
Andamese MtDNA M and
Y-DNA Haplogroup D D-M174
Aboriginal Australian MtDNA M and Y-DNA Haplogroup C,
Haplogroup K
- published: 26 Apr 2016
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