February 25, 2012

Maternal ancestry of Jamaicans

Jamaican slave revolt of 1759 (source)
There is a new study on the mitochondrial DNA of Jamaicans, shedding some light on the ancestry of this Caribbean nation:


I must certainly commend the historical introduction, which is not just comprehensive but also easy to follow and understand and well integrated with the information provided by the mitochondrial DNA findings. 

While there are a handful of lineages rooted in Native America or North of the Sahara (but not European), the overwhelming majority of the more than 400 Jamaican matrilineages studied in their HVS-I region have their roots in Africa. 

The most informative findings are however those about the regional origins within Africa of  the ancestors of modern Jamaicans. The Gold Coast and Bight of Benin regions (between Assini and the Niger Delta per fig. 1) are the main sources of Jamaican ancestry. Other West African regions (Sierra Leone, Bight of Biafra and West-Central Africa) were secondary sources only, while South and East Africa is almost not represented. 

This last appears to have surprised the authors, who expected more impact of the late slave trade based largely on the Indian Ocean coasts, similarly they seem a bit perplex by the relatively low influence of the Bight of Biafra, another major late source of African slaves. They argue that greater traveled distances may have hurt the chances of survival of people being transported from farther away (a documented fact) and that creole slaves, those born in the Caribbean, had much better chances of survival and even some chances of upward mobility.

See also: African ancestry of the Noir Marron of the Guianas, a previous example of the same approach cited in this paper. In that case however the bulk of the ancestry was from the Biafra area.

8 comments:

  1. Thanks, Maju, this is fascinating data.

    "the non-Sub-Saharan paragroup accounted for 2.5% of the typed Jamaicans"

    The study found 10 individuals with non-Black mtDNA, of 400 total individuals in the study-population.

    Amerindian lines [1% of sample mtDNA]
    A2: 1 person
    B2: 1 person
    D4: 2 people

    'Eurasian' lines [1% of sample mtDNA]
    H: 1 person
    J: 2 people
    U2: 1 person

    'Worldwide' [0.5% of sample mtDNA]
    M: 2 people

    How could an mtDNA haplogroup be 'worldwide'? Maju, please help us understand this.

    On the 'Eurasian' lines:
    "On the other hand, there are few haplotypes of European
    ancestry in Jamaica. The H2a2b1 profile A16235G C16291T A16293G was observed in
    Bolzano (Italy) [20], in Galicia (Spain) [21]; in the USA, this haplotype is quite common as it
    appeared many times in the Genographic database [22]. Curiously, no matches have been
    found for some of the European profiles, e.g. the J haplotype T16126C C16187T T16189C
    and the U2 haplotype A16051G A16206C C16291T T16359C. The presence of these
    lineages in the modern population may highlight the rapid assimilation of a small albeit
    global workforce arriving to a post-emancipation Jamaica during the subsequent labour
    shortage
    ."

    How could the European line H2a2b1 have ended up in the Jamacian-Black genepool?

    ReplyDelete
  2. Of note, the B2, D4, and perhaps even the perfect match native Central American A2 mtdna lineage may not have been native to Jamaica. As documented by Gallay and more recently Kelton, the British-Indian (various Indian tribes were both collaborators with the British and the victims) slave trade 1659-1717 greatly depopulated the SE region of native N America.

    The captives were exported from Charleston and traded in the sugar islands at a ratio of 3 Indians for 2 Africans (Gallay). This was due to the impracticality of enslaving the Indians on their own continent. Africans imported to Carolina were not allowed to learn native languages, and the collaborating Indians were offered bounties to return escaped Africans.

    As to the A2, the original natives of Florida were essentially completely killed or exported so their mtdna would not be represented in samples of modern Florida Indians (Seminoles). I suspect that the original Florida native mtdna pool could have been very similar to that of the islands and modern Central America.

    ReplyDelete
  3. "Thanks, Maju"...

    Thanks to you for visiting and producing interesting comments. :)

    "How could an mtDNA haplogroup be 'worldwide'?"

    Guess that the authors could not decide what region it is from. Macro-haplogroup M is original from Asia, probably South Asia but, through time, it has migrated (in diverse form) to many other places, including Africa (M1 but at least also some other rare lineage in Madagascar). [Note: that D is also part of M but in this case the Native American origin is so likely that they had no doubt].

    "How could the European line H2a2b1 have ended up in the Jamacian-Black genepool?"

    Whites were also sometimes enslaved, notably the Irish. At the beginnings of Modern Age slavery was considered "moral" with people of other religions and only later this degenerated in a racist interpretation of which we are still hostages to some degree. Anyhow, being a single lineage in a single person, the origins can be many.

    The authors for example consider that, after abolition, the arrival of workers from other areas (Middle East or India implicit) may have brought some of those non-African, non-European lineages. But again the possibilities are many and I would not give these erratics any special importance.

    ReplyDelete
  4. "Of note, the B2, D4, and perhaps even the perfect match native Central American A2 mtdna lineage may not have been native to Jamaica".

    Of course. What you say, Joy, is important (and very interesting) but I guess it is impossible to know for sure. It's also possible that some native Jamaican matrilineages survived or that these belong to native or mixed slaves from Central America (Belize, Miskito Coast).

    Ultimately the pre-Columbian natives of the Caribbean (Taínos, Carib, etc.) were probably original, not from North American or Central America but from the area of Venezuela-Guayanas. At least the Taínos of the Greater Antiles are considered relatives of the Arawak of the Orinoco.

    ReplyDelete
  5. @hailtoyou, @Maju

    Yes the Irish were the first slaves in the British colonies in the New World, and 10's of thousands, some accounts put it at 100's of thousands of Irish slaves were exported to the Caribbean. But the vast majority died out as they weren't suitable for tropical/sub-tropical plantation work. The term "redneck" or "redleg" refers to the pejorative term African slaves called Irish slaves. Some Irish slaves survived long enough to intermarry with African slaves, plus some Irish slave girls were forcibly bred with African male slaves to produce a lighter complected household slave, for sale in the Carolinas.

    My parents are 100% Irish and have 100% Jamaican relatives - as identified by 23andMe. My father also has relatives in Barbados and the Bahamas.

    I searched for H2a2b1 among my relatives, and its present in 6 of them

    ReplyDelete
  6. @Maju - So very likely Irish, right?

    Absolutely IMO!

    BTW, I also have 9 mtDNA A2 relatives, plus 1 A2c. Of the A2's, two are Central American, one if from El Salvador and I don't know much about her, the other is from Guatemala. The one from Guatemala stated that her father was 100% Maya, and her mother 1/2 Maya/1/2 Mestizo, then when she later tested her Dad, it turned out that he and my father were related?! Both my parents also have numerous relatives in Mexico.

    ReplyDelete
  7. Hail
    "How could the European line H2a2b1 have ended up in the Jamacian-Black genepool?"

    Don't forget there would have been prostitutes working the garrisons. It wouldn't be at all surprising if some of them had a mixture of white and mixed-race kids.

    ReplyDelete

Please, be reasonably respectful when making comments. I do not tolerate in particular sexism, racism nor homophobia. Personal attacks, manipulation and trolling are also very much unwelcome here.The author reserves the right to delete any abusive comment.

Preliminary comment moderation is... ON (sorry, too many trolls).