| Abstract: |
The origin of the native inhabitants of the island of Nias is unknown. Linguistics is not very helpful, as archaeology indicates settlement dates of at least 12,000 years BP, well before the expansion of Austronesian, the only language spoken there today. We investigated the genetic history of the paternal (Y-chromosomes) and the maternal (mitochondrial DNA) lineages from more than 900 people out of 11 representative clans throughout the island. The Pre-Austronesian peoples seem to have left no significant genetic footprint in the contemporary population studied, and there is also no admixture of South Asian and recent European Y-chromosomes. In contrast to around 20 selected Y-chromosome haplogroups representative for Southeast Asia, surprisingly, only two were found. The Y-haplogroups that were found have been identified as a marker of East and Southeast Asian genetic origin with highest frequencies in Taiwanese indigenous population and in the Philippines. The mitochondrial haplogroups are more variable but still have a highly skewed distribution. Moreover, paternal lineages, and to a lesser extent the maternal lineages, exhibit greatly reduced overall genetic diversity, contrary to what would be expected. Over time a continuous genetic admixture would be expected as Nias lies within a chain of islands just 120km from the west coast of Sumatra. At present, we have no idea what type of extreme selective pressure would lead to such a male-biased bottleneck or founder event with the subsequent isolation of the expanding population
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