Negritos are the most genetically distant human population from Africans at most loci studied thus far (except for MC1R, which codes for dark skin).
They have also been shown to have separated early from Asians, suggesting that they are either surviving descendants of settlers from an early migration out of Africa, commonly referred to as the Proto-Australoids, or that they are descendants of one of the founder populations of modern humans.
Occasionally, some Negritos are referred to as pygmies, bundling them with peoples of similar physical stature in Central Africa, and likewise, the term Negrito was previously occasionally used to refer to African Pygmies.
Origins
Being among the least-known (by outsiders) of all living human groups, the origins of the Negrito people is much debated. The Malay term for them is orang asli, or aborigines.They are likely descendants of the indigenous Australoid populations of the Sunda landmass and New Guinea, predating the Austronesian peoples who later entered Southeast Asia.
Alternatively, some scientists claim they are merely a group of Australo-Melanesians who have undergone island dwarfing over thousands of years, reducing their food intake in order to cope with limited resources and adapt to a tropical rainforest environment.
Anthropologist Jared Diamond in his book, Guns, Germs, and Steel suggests that the Negritos are possible ancestors of the Aboriginal Australians and Papuans of New Guinea, groups regarded as Australoid.
A number of features would seem to suggest a common origin for the Negritos and African pygmies, especially in the Andamanese Islanders who have been isolated from incoming waves of Asiatic and Caucasoid peoples. No other living human population has experienced such long-lasting isolation from contact with other groups.
These features include short stature, very dark skin, woolly hair, scant body hair and occasional steatopygia. The claim that Andamanese pygmoids more closely resemble Africans than Asians in their cranial morphology in a 1973 study added some weight to this theory before genetic studies pointed to a closer relationship with Asians.
Other more recent studies have shown closer craniometric affinities to Egyptians and Europeans than to Sub Saharan populations such as that of African Pygmies. Walter Neves' study of the Lagoa Santa people had the incidental correlation of showing Andamanese as classifying closer to Egyptians and Europeans than any Sub Saharan population.
Multiple studies also show that Negritos from Southeast Asia to New Guinea share a closer cranial affinity with Australo-Melanesians. Further evidence for Asian ancestry is in craniometric markers such as sundadonty, shared by Asian and Negrito populations.
It has been suggested that the craniometric similarities to Asians could merely indicate a level of interbreeding between Negritos and later waves of people arriving from the Asian mainland. This hypothesis is not supported by genetic evidence that has shown the level of isolation populations such as the Andamanese have had.
However, 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, Malay Peninsula, and Philippines.
A study on blood groups and proteins in the 1950s suggested that the Andamanese were more closely related to Oceanic peoples than Africans. Genetic studies on Philippine Negritos, based on polymorphic blood enzymes and antigens, showed they were similar to surrounding Asian populations. Genetic testing places all the Onge and all but two of the Great Andamanese in the mtDNA Haplogroup M found in East Africa, East Asia, and South Asia, suggesting that the Negritos are at least partly descended from a migration originating in eastern Africa as much as 60,000 years ago. This migration is hypothesized to have followed a coastal route through India and into Southeast Asia, which is sometimes referred to as the Great Coastal Migration.
Analysis of mtDNA coding sites indicated that these Andamanese fall into a subgroup of M not previously identified in human populations in Africa and Asia. These findings suggest an early split from the population of migrants from Africa; the descendants of these migrants would eventually populate the entire habitable world. Haplogroup C-M130 and haplogroup D-M174 are believed to represent Y-DNA in the migration.
A recent genetic study found that unlike other early groups in Malesia, Andamanese Negritos lack the Denisovan hominin admixture in their DNA, while other Negrito groups may show some varying degree of Denisovan ancestry. Denisovan ancestry is found among indigenous Melanesian and Australian populations between 4-6%
Historical distribution
Negritos may have also lived in Taiwan, where they were called the "Little Black People". Apart from being short-statured, they were also said to be broad-nosed and dark-skinned with curly hair.[The little black population shrank to the point that, up to 100 years ago, only one small group lived near the Saisiyat tribe. A festival celebrated by the Saisiyat gives evidence to their former habitation of Taiwan. The Saisiyat tribe celebrate the black people in a festival called Ritual of the Little Black People (矮靈祭).According to James J.Y. Liu, a professor of comparative literature, the Chinese term Kun-lun (崑崙) means Negrito.
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