Limits...
Genetic evidence of African slavery at the beginning of the trans-Atlantic slave trade.

Martiniano R, Coelho C, Ferreira MT, Neves MJ, Pinhasi R, Bradley DG - Sci Rep (2014)

Bottom Line: The Leprosarium site samples were less preserved but gave some probability of both African and European ancestry.The two discard deposit burials each gave African affinity signals, which were further refined toward modern West African or Bantu genotyped samples.These data from distressed burials illustrate an African contribution to a low status stratum of Lagos society at a time when this port became a hub of the European trade in African slaves which formed a precursor to the transatlantic transfer of millions.

View Article: PubMed Central - PubMed

Affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland.

ABSTRACT
An archaeological excavation in Valle da Gafaria (Lagos, Portugal), revealed two contiguous burial places outside the medieval city walls, dating from the 15(th)-17(th) centuries AD: one was interpreted as a Leprosarium cemetery and the second as an urban discard deposit, where signs of violent, unceremonious burials suggested that these remains may belong to slaves captured in Africa by the Portuguese. We obtained random short autosomal sequence reads from seven individuals: two from the latter site and five from the Leprosarium and used these to call SNP identities and estimate ancestral affinities with modern reference data. The Leprosarium site samples were less preserved but gave some probability of both African and European ancestry. The two discard deposit burials each gave African affinity signals, which were further refined toward modern West African or Bantu genotyped samples. These data from distressed burials illustrate an African contribution to a low status stratum of Lagos society at a time when this port became a hub of the European trade in African slaves which formed a precursor to the transatlantic transfer of millions.

Show MeSH

Related in: MedlinePlus

Sex identification based on shotgun sequencing data.Ry - Ratio of the number of reads aligned to the Y-chromosome divided by the sum of the number reads aligned to the Y- and X-chromosomes. Gray shaded areas represent threshold for acceptance of assignment, calibrated with modern and ancient genomes11. Error bars correspond to 95% confidence intervals.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4125989&req=5

f2: Sex identification based on shotgun sequencing data.Ry - Ratio of the number of reads aligned to the Y-chromosome divided by the sum of the number reads aligned to the Y- and X-chromosomes. Gray shaded areas represent threshold for acceptance of assignment, calibrated with modern and ancient genomes11. Error bars correspond to 95% confidence intervals.

Mentions: Sex estimation can sometimes be crucial to understand certain archaeological contexts and it can be a very challenging task for anthropologists, especially when dealing with young individuals, bone degradation or absence of more sexually dimorphic bones such as the pelvis. A recently published method11, calibrated with modern and ancient sequence data, has shown that it is possible to confidently obtain this information by estimating the fraction of reads that map to the X- and Y-chromosomes. We applied this method to our data (Figure 2 and Supplementary Table S1) and determined that all samples were female, with the exception of Individual 36. Confidence intervals of sex determination for Sample 5 and 36 overlap the stringent boundaries of certainty (Female if Ry > 0.016, Male if Ry < 0.075, represented by gray shaded areas), but more sequence data would likely reveal that these assignments are correct.


Genetic evidence of African slavery at the beginning of the trans-Atlantic slave trade.

Martiniano R, Coelho C, Ferreira MT, Neves MJ, Pinhasi R, Bradley DG - Sci Rep (2014)

Sex identification based on shotgun sequencing data.Ry - Ratio of the number of reads aligned to the Y-chromosome divided by the sum of the number reads aligned to the Y- and X-chromosomes. Gray shaded areas represent threshold for acceptance of assignment, calibrated with modern and ancient genomes11. Error bars correspond to 95% confidence intervals.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4125989&req=5

f2: Sex identification based on shotgun sequencing data.Ry - Ratio of the number of reads aligned to the Y-chromosome divided by the sum of the number reads aligned to the Y- and X-chromosomes. Gray shaded areas represent threshold for acceptance of assignment, calibrated with modern and ancient genomes11. Error bars correspond to 95% confidence intervals.
Mentions: Sex estimation can sometimes be crucial to understand certain archaeological contexts and it can be a very challenging task for anthropologists, especially when dealing with young individuals, bone degradation or absence of more sexually dimorphic bones such as the pelvis. A recently published method11, calibrated with modern and ancient sequence data, has shown that it is possible to confidently obtain this information by estimating the fraction of reads that map to the X- and Y-chromosomes. We applied this method to our data (Figure 2 and Supplementary Table S1) and determined that all samples were female, with the exception of Individual 36. Confidence intervals of sex determination for Sample 5 and 36 overlap the stringent boundaries of certainty (Female if Ry > 0.016, Male if Ry < 0.075, represented by gray shaded areas), but more sequence data would likely reveal that these assignments are correct.

Bottom Line: The Leprosarium site samples were less preserved but gave some probability of both African and European ancestry.The two discard deposit burials each gave African affinity signals, which were further refined toward modern West African or Bantu genotyped samples.These data from distressed burials illustrate an African contribution to a low status stratum of Lagos society at a time when this port became a hub of the European trade in African slaves which formed a precursor to the transatlantic transfer of millions.

View Article: PubMed Central - PubMed

Affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland.

ABSTRACT
An archaeological excavation in Valle da Gafaria (Lagos, Portugal), revealed two contiguous burial places outside the medieval city walls, dating from the 15(th)-17(th) centuries AD: one was interpreted as a Leprosarium cemetery and the second as an urban discard deposit, where signs of violent, unceremonious burials suggested that these remains may belong to slaves captured in Africa by the Portuguese. We obtained random short autosomal sequence reads from seven individuals: two from the latter site and five from the Leprosarium and used these to call SNP identities and estimate ancestral affinities with modern reference data. The Leprosarium site samples were less preserved but gave some probability of both African and European ancestry. The two discard deposit burials each gave African affinity signals, which were further refined toward modern West African or Bantu genotyped samples. These data from distressed burials illustrate an African contribution to a low status stratum of Lagos society at a time when this port became a hub of the European trade in African slaves which formed a precursor to the transatlantic transfer of millions.

Show MeSH
Related in: MedlinePlus