New research suggests Madagascar seeded by some 30 Indonesian women

Archaeologists have long known about the linguistic and genetic links between Madagascar and Indonesia; new research suggests that Madagascar was populated fairly recently from a small pool of approximately 30 Indonesian women. At 1,200 years ago, this would put it right at the time when Srivijaya was the dominant power in the islands. Interesting, but also not surprising!

A small cohort of Island Southeast Asian women founded Madagascar
Murray P. Cox, Michael G. Nelson, Meryanne K. Tumonggor, François-X. Ricaut and Herawati Sudoyo
Published online before print March 21, 2012, doi: 10.1098/rspb.2012.0012
Proc. R. Soc. B

30 Indonesian Women (Accidentally) Founded Madagascar
Live Science, 20 March 2012

Abstract:
The settlement of Madagascar is one of the most unusual, and least understood, episodes in human prehistory. Madagascar was one of the last landmasses to be reached by people, and despite the island’s location just off the east coast of Africa, evidence from genetics, language and culture all attests that it was settled jointly by Africans, and more surprisingly, Indonesians. Nevertheless, extremely little is known about the settlement process itself. Here, we report broad geographical screening of Malagasy and Indonesian genetic variation, from which we infer a statistically robust coalescent model of the island’s initial settlement. Maximum-likelihood estimates favour a scenario in which Madagascar was settled approximately 1200 years ago by a very small group of women (approx. 30), most of Indonesian descent (approx. 93%). This highly restricted founding population raises the possibility that Madagascar was settled not as a large-scale planned colonization event from Indonesia, but rather through a small, perhaps even unintended, transoceanic crossing.

Excerpt from story:

Previous genetic research showed that, surprisingly, instead of coming from Africa, the people living on the island off the east coast of Africa seem to have come from Indonesia, another island nation a quarter of the world, or some 3,500 miles (about 5,600 kilometers), away.

“What we haven’t known is exactly how that happened. When did those people arrive and how did they arrive?” Cox said.

To find out, Cox and his colleagues analyzed genes from the mitochondria of 300 native Madagascans and 3,000 Indonesians. Mitochondria are the cell’s energy factories, but they are special because their genes are inherited only from our mothers.

These genes showed a clear similarity between the Indonesian and Madagascar genomes. To find out how long ago and how many Indonesian settlers there when the island’s population was founded, the team ran various computer simulations that started out with different founding populations at different times until the results matched their real-life data. The researchers found that the island was most likely settled by a small population of about 30 women, who arrived in Madagascar around 1,200 years ago. Ninety-three percent (28) of these women were Indonesian, and the other 7 percent (two individuals) were African.

Full story here.