As an anthropologist, I always wanted to know if Asians, known for their extensive linguistic and ethnic diversity also have a substantial level of genetic variation. In other words, do they have a common or multiple origins? Or whether the ancestors of Negritos from Philippines, Malaysia and Indonesia differ from those of their neighboring Asians? Or what binds us more: language or geography? The recent paper published in Science by the HUGO Pan-Asian SNP Consortium – Mapping Human Genetic Diversity in Asia quintessentially answers these fundamental questions which have been floating around for years.
To the best of my understanding, so far, this is the only paper where 73 populations scattered across 10 Asian countries are studied together through a massive collaborative effort of scientists from 40 institutes mostly from Asia (~2000 samples covering almost entire spectrum of linguistic and ethnic diversity were genotyped for ~50000 single nucleotide polymorphic markers). Some of the key findings of this paper are:
· East and Southeast Asians share a common origin.
· East Asians have mainly originated from South East Asian populations with minor contributions from Central-South Asian groups.
· A common ancestor of the Negrito and non-Negrito populations of Asia entered into the continent. This supports the hypothesis of one wave of migration into Asia as opposed to two waves of migrations from Africa.
· The Taiwan aborigines are derived from Austronesian populations. This stands in contrast to the suggestion that this island served as the ancestral “homeland” for Austronesian speaking populations throughout the Indo-Pacific.
· Genetic ancestry is highly correlated with linguistic affiliations as well as geography.
The paper stands out in its attempt to understand the peopling of Asia and their genetic relationships and in the process it not only presents a fantastic genotype database but also provides vital clues to scientists of diverse fields –from linguistics to archeology to human genetics. For example, it may be an interesting proposition for a human geneticist to examine if East and Southeast Asians share, more than expected, risk alleles associated with diseases. Likewise, it may be time for the linguists to re-look at the “birthplace” of the Austronesian linguistic family. I hope the consortium continues with their amazing endeavor and include a lot more number of important and isolated populations from whole of Asia and move beyond the analysis of Single Nucleotide Polymorphism to other kinds such as structural variations.