175
We also observed a unique pattern of allele frequency spectra in Orang Asli of
similar sub-tribes; HNA alleles (i.e. HNA-4 and HNA-5) and several single nucleotide polymorphisms (SNP) in pro-inflammatory (IL12-1188A/C and IL2+166G/T)
and anti-inflammatory (IL-10-819C/T and IL-10-1082A/G) cytokine genes distributed differently in Proto-Malays (i.e. the Orang Kanaq) as compared with their
other Austronesian relatives, the Malay subethnic groups (Norhalifah et al. 2016b;
Manaf et al. 2016). Genetic differences between these Austronesian groups may be
due to isolation and bottleneck events that took place in the Orang Kanaq. The
Orang Kanaq currently live as a small group in the interior of Peninsular Malaysia
(Musa 2011) as opposed to Malay subethnic groups. The latter group is numerically
larger and have admixed with other major sub-populations including with the modern Malays (i.e. Deutro-Malays), Chinese and Indians. Similar effects were observed
for the HLA loci, the most polymorphic region in human genome, where only 43
alleles were recorded across the HLA-A, HLA-B and HLA–DRB1 genes of the
Kensiu and Semai people. These Orang Asli sub-tribes also have fixed human platelet antigen (HPA) (HPA-2a, HPA-4a, HPA-6a) and TGF-β1 +915G cytokine systems. Only 10 and 9 KIR genotypes were detected in Kensiu and Semai, respectively
(Norhalifah et al. 2016b; Syafawati et al. 2016; Tasnim et al. 2016; NurWaliyuddin
et al. 2015). Overall, these apparently distinctive genepools of Orang Asli are the
result genetic refinement via admixture, founder effects and selective pressure after
multiple settlements and long periods of isolation since they settled in Peninsular
Malaysia.
The current trends in genetic ancestry studies focus on large scale SNP surveys
and whole genome sequencing because they generate large volumes of data (Wong
et al. 2013; Lipson et al. 2014). This new development contributes towards our
present understanding of ancestral and admixture fractions in ISEA and includes
representative Orang Asli in Peninsular Malaysia and Taiwanese aborigines. The
ancestry pattern revealed by the SNP surveys and whole genome sequencing supports our inferences using immune and histocompatibility genes. In addition, the
indigenous evolution model for ISEA was not supported from other biological
data – dental and craniometric analyses showed distinct patterns of variations
between ancient and modern human specimens in ISEA, which indicated demographic changes in the region associated with several human settlements (i.e.
Austronesian and Austroasiatic speakers) in the region from Pleistocene to 2500
YBP (Matsumura and Oxenham 2014). Skeletal analysis showed morphological
similarities between pre-Neolithic samples in ISEA (Gua Niah in Sarawak and
Tobon in the Philippines) and those from Australian Aborigines and Papuans,
which correlated with the late Pleistocene colonisation of Asia-Pacific region by
anatomically modern humans (Matsumura and Oxenham 2014). In Peninsular
Malaysia, this is related to the Semang, who are genetically and physically distinct
from the other two language families (Austronesians and Austroasiatics) of foodproducing populations, who migrated to the region in the Neolithic period
(Matsumura and Oxenham 2014; Bellwood 1997). Nonetheless, admixture did
occur between these populations and is evident in whole genome SNP analyses
(Soares et al. 2016; Deng et al. 2015; Lipson et al. 2014).
A Multidisciplinary Account of the Orang Asli in Peninsular Malaysia
We also observed a unique pattern of allele frequency spectra in Orang Asli of
similar sub-tribes; HNA alleles (i.e. HNA-4 and HNA-5) and several single nucleotide polymorphisms (SNP) in pro-inflammatory (IL12-1188A/C and IL2+166G/T)
and anti-inflammatory (IL-10-819C/T and IL-10-1082A/G) cytokine genes distributed differently in Proto-Malays (i.e. the Orang Kanaq) as compared with their
other Austronesian relatives, the Malay subethnic groups (Norhalifah et al. 2016b;
Manaf et al. 2016). Genetic differences between these Austronesian groups may be
due to isolation and bottleneck events that took place in the Orang Kanaq. The
Orang Kanaq currently live as a small group in the interior of Peninsular Malaysia
(Musa 2011) as opposed to Malay subethnic groups. The latter group is numerically
larger and have admixed with other major sub-populations including with the modern Malays (i.e. Deutro-Malays), Chinese and Indians. Similar effects were observed
for the HLA loci, the most polymorphic region in human genome, where only 43
alleles were recorded across the HLA-A, HLA-B and HLA–DRB1 genes of the
Kensiu and Semai people. These Orang Asli sub-tribes also have fixed human platelet antigen (HPA) (HPA-2a, HPA-4a, HPA-6a) and TGF-β1 +915G cytokine systems. Only 10 and 9 KIR genotypes were detected in Kensiu and Semai, respectively
(Norhalifah et al. 2016b; Syafawati et al. 2016; Tasnim et al. 2016; NurWaliyuddin
et al. 2015). Overall, these apparently distinctive genepools of Orang Asli are the
result genetic refinement via admixture, founder effects and selective pressure after
multiple settlements and long periods of isolation since they settled in Peninsular
Malaysia.
The current trends in genetic ancestry studies focus on large scale SNP surveys
and whole genome sequencing because they generate large volumes of data (Wong
et al. 2013; Lipson et al. 2014). This new development contributes towards our
present understanding of ancestral and admixture fractions in ISEA and includes
representative Orang Asli in Peninsular Malaysia and Taiwanese aborigines. The
ancestry pattern revealed by the SNP surveys and whole genome sequencing supports our inferences using immune and histocompatibility genes. In addition, the
indigenous evolution model for ISEA was not supported from other biological
data – dental and craniometric analyses showed distinct patterns of variations
between ancient and modern human specimens in ISEA, which indicated demographic changes in the region associated with several human settlements (i.e.
Austronesian and Austroasiatic speakers) in the region from Pleistocene to 2500
YBP (Matsumura and Oxenham 2014). Skeletal analysis showed morphological
similarities between pre-Neolithic samples in ISEA (Gua Niah in Sarawak and
Tobon in the Philippines) and those from Australian Aborigines and Papuans,
which correlated with the late Pleistocene colonisation of Asia-Pacific region by
anatomically modern humans (Matsumura and Oxenham 2014). In Peninsular
Malaysia, this is related to the Semang, who are genetically and physically distinct
from the other two language families (Austronesians and Austroasiatics) of foodproducing populations, who migrated to the region in the Neolithic period
(Matsumura and Oxenham 2014; Bellwood 1997). Nonetheless, admixture did
occur between these populations and is evident in whole genome SNP analyses
(Soares et al. 2016; Deng et al. 2015; Lipson et al. 2014).
A Multidisciplinary Account of the Orang Asli in Peninsular Malaysia