Researchers may be a step closer to finding out where the first New Zealanders came from. University of Otago researchers have sequenced the mitochondrial DNA from several human samples extracted from the Wairau Bar burial site in the northern South Island, shedding light on the ancestry of the first New Zealanders. The Wairau Bar is an important archaeological site and is the earliest known human settlement in New Zealand.
The Otago researchers now have the complete mitochondrial genomes of four of the Rangitāne iwi tūpuna (ancestors) who were buried at a large village on the Wairau Bar more than 700 years ago.
Greater level of genetic diversity
The results from the sequencing of four human samples from the site were published in Proceedings of the National Academy of Sciences in October 2012. The results revealed there was a greater level of genetic diversity than expected in the early settlers of New Zealand.
Mitochondrial DNA is only inherited through the mother’s side and can be used to trace maternal lineages and provide insights into ancient origins and migration routes. Lead author Professor Lisa Matisoo-Smith said, “We found that three of the four individuals had no recent maternal ancestor in common, indicating that these pioneers were not simply from one tight-knit kin group, but instead included families that were not directly maternally related. This gives a fascinating new glimpse into the social structure of the first New Zealanders and others taking part in the final phases of the great Polynesian migration across the Pacific.” They also discovered that at least one of the settlers carried a genetic mutation associated with insulin resistance, which leads to type 2 diabetes.
Unique genetic markers
Now that the researchers have identified several unique genetic markers in New Zealand's founding population, work can begin to obtain and sequence other ancient and modern DNA samples from Pacific islands and search for these same markers. Comparisons between archaeological samples from New Zealand and other sequences from the Pacific region could also provide answers about where the first New Zealanders came from.
Read this article to find out more about DNA sequencing.
In relation to this news article, your students may like to try this activity in which they gain an understanding of why genetic diversity within a population is important.
Exploring genetic variation