Limits...
The trans-Saharan slave trade - clues from interpolation analyses and high-resolution characterization of mitochondrial DNA lineages.

Harich N, Costa MD, Fernandes V, Kandil M, Pereira JB, Silva NM, Pereira L - BMC Evol. Biol. (2010)

Bottom Line: Ages for the haplogroups observed in both sides of the Saharan desert testify the recent origin (holocenic) of these haplogroups in sub-Saharan Africa, claiming a recent introduction in North Africa, further strengthened by the no detection of local expansions.The interpolation analyses and complete sequencing of present mtDNA sub-Saharan lineages observed in North Africa support the genetic impact of recent trans-Saharan migrations, namely the slave trade initiated by the Arab conquest of North Africa in the seventh century.Sub-Saharan people did not leave traces in the North African maternal gene pool for the time of its settlement, some 40,000 years ago.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratoire d'Anthropogénétique, Départment de Biologie, Faculté des Sciences, Université Chouaïb Doukkali, El Jadida, Morocco.

ABSTRACT

Background: A proportion of 1/4 to 1/2 of North African female pool is made of typical sub-Saharan lineages, in higher frequencies as geographic proximity to sub-Saharan Africa increases. The Sahara was a strong geographical barrier against gene flow, at least since 5,000 years ago, when desertification affected a larger region, but the Arab trans-Saharan slave trade could have facilitate enormously this migration of lineages. Till now, the genetic consequences of these forced trans-Saharan movements of people have not been ascertained.

Results: The distribution of the main L haplogroups in North Africa clearly reflects the known trans-Saharan slave routes: West is dominated by L1b, L2b, L2c, L2d, L3b and L3d; the Center by L3e and some L3f and L3w; the East by L0a, L3h, L3i, L3x and, in common with the Center, L3f and L3w; while, L2a is almost everywhere. Ages for the haplogroups observed in both sides of the Saharan desert testify the recent origin (holocenic) of these haplogroups in sub-Saharan Africa, claiming a recent introduction in North Africa, further strengthened by the no detection of local expansions.

Conclusions: The interpolation analyses and complete sequencing of present mtDNA sub-Saharan lineages observed in North Africa support the genetic impact of recent trans-Saharan migrations, namely the slave trade initiated by the Arab conquest of North Africa in the seventh century. Sub-Saharan people did not leave traces in the North African maternal gene pool for the time of its settlement, some 40,000 years ago.

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Interpolation maps for L2 haplogroup in the sub-Saharan pool observed in each sample.
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Figure 5: Interpolation maps for L2 haplogroup in the sub-Saharan pool observed in each sample.

Mentions: L2 total (Figure 5) is one of the two dominant haplogroups in the L pool, in many regions across Africa, namely in central-west and south-east regions, most probably due to Bantu expansion [11,12] and towards north-west, potentially due to the trans-Saharan slave trade. The very central African populations, mostly Pygmy groups, present low proportions of L2 lineages in its pool. This pattern is caused mainly by sub-haplogroup L2a, the most frequent lineage in L2, while L2b, L2c and L2d attain highest proportions in the west coast between Senegal and Mauritania.


The trans-Saharan slave trade - clues from interpolation analyses and high-resolution characterization of mitochondrial DNA lineages.

Harich N, Costa MD, Fernandes V, Kandil M, Pereira JB, Silva NM, Pereira L - BMC Evol. Biol. (2010)

Interpolation maps for L2 haplogroup in the sub-Saharan pool observed in each sample.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2875235&req=5

Figure 5: Interpolation maps for L2 haplogroup in the sub-Saharan pool observed in each sample.
Mentions: L2 total (Figure 5) is one of the two dominant haplogroups in the L pool, in many regions across Africa, namely in central-west and south-east regions, most probably due to Bantu expansion [11,12] and towards north-west, potentially due to the trans-Saharan slave trade. The very central African populations, mostly Pygmy groups, present low proportions of L2 lineages in its pool. This pattern is caused mainly by sub-haplogroup L2a, the most frequent lineage in L2, while L2b, L2c and L2d attain highest proportions in the west coast between Senegal and Mauritania.

Bottom Line: Ages for the haplogroups observed in both sides of the Saharan desert testify the recent origin (holocenic) of these haplogroups in sub-Saharan Africa, claiming a recent introduction in North Africa, further strengthened by the no detection of local expansions.The interpolation analyses and complete sequencing of present mtDNA sub-Saharan lineages observed in North Africa support the genetic impact of recent trans-Saharan migrations, namely the slave trade initiated by the Arab conquest of North Africa in the seventh century.Sub-Saharan people did not leave traces in the North African maternal gene pool for the time of its settlement, some 40,000 years ago.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratoire d'Anthropogénétique, Départment de Biologie, Faculté des Sciences, Université Chouaïb Doukkali, El Jadida, Morocco.

ABSTRACT

Background: A proportion of 1/4 to 1/2 of North African female pool is made of typical sub-Saharan lineages, in higher frequencies as geographic proximity to sub-Saharan Africa increases. The Sahara was a strong geographical barrier against gene flow, at least since 5,000 years ago, when desertification affected a larger region, but the Arab trans-Saharan slave trade could have facilitate enormously this migration of lineages. Till now, the genetic consequences of these forced trans-Saharan movements of people have not been ascertained.

Results: The distribution of the main L haplogroups in North Africa clearly reflects the known trans-Saharan slave routes: West is dominated by L1b, L2b, L2c, L2d, L3b and L3d; the Center by L3e and some L3f and L3w; the East by L0a, L3h, L3i, L3x and, in common with the Center, L3f and L3w; while, L2a is almost everywhere. Ages for the haplogroups observed in both sides of the Saharan desert testify the recent origin (holocenic) of these haplogroups in sub-Saharan Africa, claiming a recent introduction in North Africa, further strengthened by the no detection of local expansions.

Conclusions: The interpolation analyses and complete sequencing of present mtDNA sub-Saharan lineages observed in North Africa support the genetic impact of recent trans-Saharan migrations, namely the slave trade initiated by the Arab conquest of North Africa in the seventh century. Sub-Saharan people did not leave traces in the North African maternal gene pool for the time of its settlement, some 40,000 years ago.

Show MeSH