Saturday, October 6, 2018

Dropped Off in the Caribbean: DNA and the Middle Passage


Many of us African Americans have Caribbean roots. We may fall into one of four categories: (1) Born in the Caribbean and emigrated to America; (2) Had parents and/or grandparents who were originally from the Caribbean; (3) Had a great-grandparent or a further ancestor whose Caribbean origins are known and documented; or (4) Have no known Caribbean-born ancestors within several generations of our family, but we plausibly theorize that at least one enslaved ancestor may have been from the Caribbean, or a distant family member ended up in the Caribbean, based on what we know or think we know about the transatlantic slave trade. I am in category 4.

Many seem to believe that a majority of our African ancestors, who were brought to the United States, were in the Caribbean first for a period of time. That is not the case. Historians estimate that the vast majority, over 80 percent, of enslaved Africans disembarked in the United States came directly from Africa. The majority had never stepped foot on Caribbean soil. However, many of us, who are in category 4, are garnering DNA evidence that suggests strong ties to the Caribbean. In our databases of DNA relatives from, 23andMe, MyHeritage, etc., some of our genetic cousins or their parents are from Jamaica, Barbados, Puerto Rico, Trinidad and Tobago, Cuba, Haiti, Grenada, and other places in the Caribbean. Here’s one example I discovered that involves DNA triangulation.

Per 23andMe, a DNA cousin, who I will call “Cousin Alvarez,” shares 23 cM [4553 SNPs] of identical DNA on chromosome 4 with my mother, her brother, and their first cousin, who is my grandfather’s niece. That amount of DNA is in the predicted 4th cousin range, but it doesn’t necessarily mean that Cousin Alvarez is their 4th cousin, who shares the same third-great-grandparent(s). But what is most interesting about Cousin Alvarez is what he wrote on his profile: “My Dad is paternal Filipino and maternal Chinese/Panamanian, and my Mom is paternal Guamanian and maternal Mexican.” Under “Ancestors Location,” he indicates that his Mom’s Mom was born in Mexico, his Mom’s Dad was born in Guam, his Dad’s Mom was born in Panama, and his Dad’s Dad was born in the Philippines. What a mix! How on earth are we related to him?

Additionally, his ancestry composition includes 6.7% Sub-Saharan African, 52.6% Southeast Asian (Guam), 24.9% European, 6.6% Native American (Panama), 1.4% Chinese, and etc. 23andMe shows an ancestry composition chromosome painting, and a large segment on his chromosome 4, where he matches my family, is Sub-Saharan African. Therefore, we share a common African ancestor from which that identical DNA on chromosome 4 originated from. Interestingly, many people of African descent from Trinidad, Martinique, Guadeloupe, Dominica, Grenada, Haiti, Barbados and Jamaica were brought to Panama to build the Panama Canal, which started construction in 1881.

Under “Relatives in Common” are six other people who are marked as "Yes" under “Shared DNA.” Having shared DNA means that you and your genetic relatives share a portion of the same identical DNA segment. In other words, each of those six DNA relatives inherited portions of that same identical Sub-Saharan African segment on chromosome 4 that Cousin Alvarez and my mother (and her brother and first cousin) inherited. All 10 of them represent a “DNA triangulation group,” roughly defined as three or more people who share a valid chromosome segment that came from a common ancestor. Three of those six people indicate close ties to the Caribbean! Let’s look at the chromosome matching with those three people.

DNA Sharing with Cousin Alvarez and My Family, Cousins A, B, & C on Chromosome 4

My Family (purple) – This is my mom, her brother, and their first cousin.

COUSIN A (orange) – She stated that her mother is from Asheville, North Carolina, her father is from Oklahoma, and her paternal grandparents are Creole from Louisiana. She also speculates that her grandmother had roots in Haiti. Sharing 64 cM on chromosome 4, Cousin A and Cousin Alvarez share a total of 115 cM over 3 segments, which is in the range of second cousins once removed to third cousins. However, she doesn't have any idea how she could be this closely related to him.

COUSIN B (gold) – On her 23andMe profile, she indicates that her Mom’s Mom was born in the U.S., her Mom’s Dad was born in Barbados, her Dad’s Mom was born in Honduras, and her Dad’s Dad was born in Belize.

COUSIN C (green) – On her 23andMe profile, she indicates that her Mom’s Dad was born in Jamaica. The other three grandparents were born in the U.S.

Fortunately, Cousin C uploaded her raw data file to, which enabled me to compare her to other relatives who had taken other DNA tests and had also uploaded to GEDmatch. To aid in solving genealogical mysteries, this process is highly recommended. I figured out that my mother, her brother and their first cousin likely inherited that matching DNA segment on chromosome 4 from their great-grandmother – their fathers’ maternal grandmother, Polly Partee of Panola County, Mississippi.

According to the 1870 and 1880 U.S. Federal Censuses, Grandma Polly was born around 1830. Her birthplace was reported as being North Carolina. By 1850, she had become enslaved by Squire Boone Partee of Panola County. Unfortunately, I haven’t been able to unearth where in North Carolina she came from and how Squire Partee obtained her. In my mind, I envision a young enslaved girl being placed on the auction block somewhere in North Carolina, sold to a speculator who takes her to Mississippi, never to see her family again, and subsequently purchased by Squire Partee. According to oral history, Grandma Polly was the head cook on the Partee plantation during and after slavery. DNA sleuthing indicates that she had family ties to once-enslaved Bullock families from Granville County, North Carolina (for a future blog post).

This discovery reminded me of a conversation that I had with my cousin’s Jamaican wife, who also tested her DNA. She observed, “I have a lot of DNA relatives from North Carolina.” North Carolina played a very small role in the transatlantic slave trade because of its geography. Just over 3,000 of the nearly 400,000 enslaved Africans who were brought to the U.S. during the Middle Passage were disembarked in North Carolina. The string of islands on the Outer Banks created dangerous conditions for slave ships to land. Consequently, most ships opted to dock in ports to the north or south of the state. One exception was Wilmington, which is located on the Cape Fear River. Wilmington became a slave port because of its accessibility. Other accessible North Carolina ports that saw some slave importation activity were Brunswick, Edenton, Beaufort, and New Bern.

Therefore, slave trading in North Carolina has largely gone unstudied. I found some slave trading data that provided a snapshot of slave trading activity in the state. It shows a strong link between the Caribbean and North Carolina. See chart below.

According to historian Walter E. Minchinton, this record of the number of enslaved people imported into North Carolina is still incomplete. However, this snapshot reveals a small yet steady flow of trade into the state during the 18th century. Enslaved people were disembarked into the state almost every year between 1720 and 1775, except the periods of war in the 1740s and 1757-1761. After the American Revolution, the trade revived and continued until 1790. Enslaved people were brought into North Carolina from both other mainland colonies and the Caribbean, with the largest percentage (48%) coming from the Caribbean. Much fewer (16%) came directly from Africa. 

Although I can’t definitively pinpoint Grandma Polly Partee’s origins in North Carolina at the moment, one thing I can plausibly assert from this DNA discovery – someone in her family was dropped off in the Caribbean and procreated there. One of Minchinton’s notations about one of the slave ships that unloaded its human cargo in North Carolina stated: The sloop Polly (104 tons) of Montego Bay, Jamaica brought Negroes from thence in 1787 and twice in 1788. Maybe a coincidence?