Madagascar was first settled and founded by approximately 30 women, mostly of Indonesian descent, who may have sailed off course in a wayward vessel 1200 years ago.
The discovery negates a prior theory that a large, planned settlement process took place on the island of Madagascar, located off the east coast of Africa. Traditionally it was thought to have been settled by Indonesian traders moving along the coasts of the Indian Ocean.
Most native Madagascar people today, called Malagasy, can trace their ancestry back to the founding 30 mothers, according to an extensive new DNA study published in the latest Proceedings of the Royal Society B,. Researchers focused on mitochondrial DNA, passed down from mothers to their offspring. Scientists assume some men were with the women.
“I’m afraid this wasn’t a settlement by Amazon seafarers!” lead author Murray Cox told Discovery News. “We propose settlement by a very small group of Indonesian women, around 30, but we also presume from the genetics that there were at least some Indonesian men with them. At this stage, we don’t know how many.”
Cox, a senior lecturer at Massey University’s Institute of Molecular BioSciences, and his colleagues analyzed genetic samples from 2745 individuals hailing from 12 Indonesian archipelago island groups. They then compared the results with genetic information from 266 individuals from three Malagasy ethnic groups: Mikea hunter-gatherers, semi-nomadic Vezo fishermen and the dominant Andriana Merina ethnic group.
Many Malagasy carry a gene tied to Indonesia. The DNA detective work indicates just 30 Indonesian women founded the Malagasy population, with a much smaller biological contribution from Africa. The women may have mated with their male Indonesian travel companions, or with men from Africa.
“The small number of Indonesian women is consistent with a single boatload of voyagers,” Cox said, adding that “typical Indonesian trading ships in the mid first millennium A.D. could hold around 500 people. “
The distance between Indonesia and Madagascar is close to 5000 miles, so the women and their travel mates must have had quite a journey, especially if it was unintended.
“The small founder population of Indonesian women makes this scenario fairly unlikely,” Cox said. “Instead, our new evidence favors a small movement of people, and perhaps even an unplanned crossing of the Indian Ocean.”
Scant archaeological evidence, consisting of a few bones marked by stone tools and an increased rate of forest fires, suggests people may have first visited, but not settled, Madagascar around 2000 years ago. Even that is very recent in terms of overall human history.
Madagascar was one of the last places on earth to have been settled, with remote islands like New Zealand, Hawaii and Easter Island being in the short group of places that were settled later -- about 900 years ago.
“Our best argument is that these islands were just extremely difficult to get to,” Cox said.
Matthew Hurles, a senior group leader at the Wellcome Trust Sanger Institute, has also studied the genetic heritage of Madagascar’s native people. He and his team also noted the Indonesian connection.
"Malagasy peoples are a roughly 50:50 mix of two ancestral groups: Indonesians and East Africans,” Hurles said. “It is important to realize that these lineages have intermingled over intervening centuries since settlement, so modern Malagasy have ancestry in both Indonesia and Africa."
Cox concluded, “It is worth emphasizing that Madagascar wasn’t a ‘sealed box’ after its initial settlement. There are notable later contributions by Africans, Arabs and Europeans. All of these contributions show up in the DNA of Malagasy today.”