Women, like this one from Indonesia, played a major role in founding Madagascar.
Credit: Francois Ricaut
The land of freaky animals and amazing biodiversity, Madagascar was also one of the last places to be settled by humans. And new research suggests that didn't happen until about 1,200 years ago.
The colonization might even have been an accident, the researchers say. A small group of Indonesian women settled the island in one fell swoop, possibly making their way there after their trading vessel capsized.
"The unusual thing about this island is Madagascar is a long way away from Indonesia. … It was also settled very recently; by this time, most of the world had already been settled," study researcher Murray Cox, of Massey University in New Zealand, told LiveScience. "We are talking about an entire culture being trans-located across the Indian Ocean." [The World's Biggest Oceans and Seas]
Mad about Madagascar
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.
Almost all native Madagascans are related to these 30 women, they found.
What about the men?
Previous research on Madagascans, specifically on the Y sex chromosome (passed from father to son), indicates that the males of this founding population were also from Southeast Asia, though they don't know how many there were.
"You see there are Indonesian Y chromosomes in the population," Cox said. "We know that both Madagascan men and women come from Indonesia, we just don't know exactly how many men. Our evidence suggests it's also a small number."
Archaeological evidence suggests that these few settlers quickly set down roots: "You have this rise and spread very rapidly to take over the island," Cox said, "perhaps in the matter of a few generations." [Gallery: Images of Uncontacted Tribes]
So, how did they get there? The researchers aren't sure. The fact that there were only 30 women, and likely no more than that of men, means it probably wasn't intentional, Cox said. He suggests that a shipping vessel, which can hold up to 500 people, could have capsized, and its travelers could have ended up on the shores of the African island.
"I wouldn't say we were sure it was an accidental voyage, but the new evidence suggests this is a good idea," Cox said.
Major ocean currents also could have pushed shipwreck survivors toward the island. During World War II, wreckage from bombings in Japan floated all the way to Africa, landing on the shores of Madagascar.
"There was even a person in a lifeboat that made it across," Cox said.
The study will be published tomorrow (March 21) in the journal Proceedings of the Royal Society B: Biological Sciences.