Between 1500 and 1850 roughly 12 million slaves were shipped from western parts of Africa to the “New World”. Extensive historical documentation of the slave trade, including volume and demographics exist but little is known about the ethnic and geographic origins of the slaves.

A group of researchers recently performed a genome wide analysis of three enslaved Africans who were buried on the island of Saint Martin in an attempt to learn more about the individuals behind the statistics.

“There are historical records – merchant ledgers, shipping records and the like – but they tend to refer to coastal shipping points rather than the slaves’ actual ethnic or geographic origins and this is where the DNA comes in. It can provide new insights where historical information is missing. To our knowledge this is the first time that genome-wide data has been used to identify the origins of enslaved Africans. And given the limited knowledge we have on the slaves’ origins this is obviously quite a breakthrough,” said Dr. Hannes Schroeder from the Centre for GeoGenetics at the Natural History Museum, University of Copenhagen in a statement.

The bodies of two men and one woman, all aged between 25 and 40 were buried in the Zoutsteeg area of Philipsburg on the Caribbean island of Saint Martin. They were unearthed during the construction of an office complex in 2010. According to previous research, the “Zoutsteeg Three” likely came directly from Africa, rather than from the Americas.

That, however, is as far as the information goes. There is no way to learn exactly who the three individuals were but the researchers believed that they could learn more than what is known now.

It is believed that the slaves died between 1660 and 1680. During that time St. Martin was ruled by the Dutch and the French. The Archives of the Slave Trade have only one record of a slave ship docking there during those years, but there is no accompanying information about the origin of the ship or the people on board.

Dr. Schroeder’s study uses a technique called whole genome capture to study poorly preserved DNA. The researchers hoped to accurately trace the geographic and ethnic origins of the slaves, rather than simply labeling them as African.

“There is a lot of information in there, but when it comes to trying to pinpoint ethnic origins, there are no records telling you where a particular individual comes from,” Schroeder told the Los Angeles Times.

The data from the genome capture were compared to genotype data from 11 West African populations.

One of the men and the woman likely came from the non-Bantu tribes in the area that now makes up Ghana and Nigeria. The second man most likely came from Northern Cameroon according to the study published in the Proceedings of the National Academy of Sciences (PNAS).

The researchers hope that the new technique, developed by Carlos Bustamante, a geneticist at Stanford University, will open the door to further analysis of other poorly preserved DNA and allow for a better understanding of history.

“What’s new about our study is that we were able to obtain genome-wide data from really poorly-preserved skeletal remains using this new technique called whole genome capture. Those remains had essentially been lying on a Caribbean beach for hundreds of years so their preservation was really not good. But by enriching the poorly preserved DNA in those samples we were able to obtain enough data to be able to dig deeper into the genetic origins of those three individuals we analyzed,” said Schroeder.