Bro, all the genetic studies show that
Portugal has substantial sub-Saharan ancestry on the female side.
The Portuguese are Afro-Iberian hybrids. Here are three scientific studies that prove this.
Diversity of mtDNA lineages in Portugal: not a genetic edge of European variation.
Annals of Human Genetics 64 (6), 491-506.
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These haplogroups have been reported to be characteristic of African populations, where their frequency is inversely correlated with the North-South axis: the frequency of U6 is high in North Africa and decreases in a southerly direction, being almost absent south of the equator; the L cluster has an opposite distribution (Rando et al. 1998, 1999; Watson et al. 1996; Mateu et al. 1996).
In Portugal, as well as generally in Iberia, many migration waves from both North and sub-Saharan African populations are well documented. The geographical proximity of North Africa and the Iberian Peninsula certainly afforded many opportunities for mutual population contacts. Among them, we stress the movement of Berbers and Arabs that took place during the very recent Muslim rule of Iberia (from the 8th century to the end of the 15th, in some regions). In addition, many sub-Saharan individuals entered the region during the slave trade period, from its very beginning (middle 15th century) until its total ban in the late 19th century.
As it would be interesting to find out the origin of the L and U6 sequences detected in Portugal, we have tried to compare the motifs of the sequences observed in Portugal with those described in the literature for several populations (Figures 3 and 4). However most of the matches found for the Portuguese sequences were with sequences widely distributed in Africa, and no clear pattern of geographic clustering was detected.
A striking aspect observed for the U6 haplogroup was that 5 out of 7 of the Portuguese sequences were unique to Portugal, not allowing, therefore, any accurate assignment of their geographical origin. The Canarian characteristic sub-haplogroup U6b1 (Rando et al. 1999), observed in other Iberian samples, was not detected in the present study.
Admitting that U6 sequences could have been at least partially introduced by Berber people during the Muslim rule of Iberia, it is strange to find them restricted to North Portugal. As a matter of fact, most historical sources document a deeper influence of Berber (as well as Arab) people in Central and particularly South Iberia (as judged from toponyms and general cultural aænities), compared to North Iberia where the Muslim presence is recorded to have been more ephemeral and consequently to have made less cultural and demographic impact. The data does not exclude the possibility that U6 introductions could have been additionally reinforced by later sub-Saharan inputs mediated by the African slave trade. Even if this mixed scenario is plausible, the presence of U6 sequences exclusively in North Portugal is a question that deserves further analysis. The hypothesis of an earlier introduction in the region does not seem to be favoured, neither by its presence in a restricted geographical area, nor by the high level of heterogeneity that characterizes the set of sequences that were found among this haplogroup.
With respect to the L sequences, it is widely accepted that they have a sub-Saharan origin, excepting some L3* lineages that, as analysis of Figure 4 suggests, might indeed have a non-African origin. The presence of L sequences in North African regions does not allow us to exclude the possibility that population influxes from this region, namely the above referred
Berber/Arab movement, have introduced significant fraction of L sequences into Iberia. However, it seems more likely that most of the L lineages found nowadays in Portugal have been carried by African slaves, since the country was actively involved in the Transatlantic slave trade. Nine out of 17 L sequences found in this study showed matches with widespread African sequences, and with regard to the 8 remaining sequences the absence of matches can be due to the present bias in the description of sub-Saharan mtDNA variability. Broad areas corresponding to Ivory Coast, Angola and Mozambique, which represented very important sources of African slaves, remain uncharacterized.
There were more African slaves in Portugal than in any other European country: in 1550, Lisbon boasted 10000 resident slaves in a population of 100000, and Portugal as a whole probably had over 40000 (Thomas, 1998). In the mid-sixteenth century the birth of slaves' children was stimulated in Portugal for internal trade purposes. Inter-breeding between autochthonous individuals and African slaves certainly occurred and the predominant mating must have been between slave African females and autochthonous males, due to social pressures and also for legal reasons: offspring of slave females would be slaves, whereas offspring of slave males would not. Therefore, breeding between slave African males and white females, besides being socially repressed, would not bring any economic profit.
If the pattern of genetic admixture was markedly sex influenced, the signature of this recent African influence would be expected to be very different in the maternally inherited gene pool and in the paternally inherited one. In a recent study based on Y chromosome biallelic markers (Pereiraet al. 2000) we have reported the absence of typical sub-Saharan haplogroups in the Y chromosome Portuguese pool. This finding, and the detection of L sequences at 7.1% in the mitochondrial pool, both seem to support the above-mentioned pattern of admixture with African slaves.
Sharing the features of mtDNA diversity generally registered in Europeans (all European haplogroups were detected), Portugal has in addition received significant North and sub-Saharan African influences. Frequencies of haplogroups specific to these regions were higher than those reported for other European populations: 7% of North African sequences were detected (restricted to North Portugal and representing almost 3%of the total sample), and sub-Saharan African sequences were found to be spread throughout the country, with frequencies between 5% and 9.8%. Although statistically significant differences were not detected between the three sub-samples considered, the geographic distribution pattern observed for U6 and L sequences strongly suggest that different population movements were responsible for their introduction into the country, although none of them had enough demographic impact to induce regional differentiation.
The introduction of L sequences in Portugal was tentatively imputed mainly to the modern slave trade that occurred between the 15th and 19th centuries. Both the great number of slaves that entered Portugal and their very diverse African geographic origin are consistent with the data set now reported. However, we cannot exclude some North-African contribution to present-day Portuguese L lineages.
While the population movement associated with the slave trade may be responsible by some U6 inputs, we suggest that U6 sequences were predominantly introduced into Portugal during the Berber/Arab invasion of the Peninsula. However, the observation that haplogroup U6 is restricted to North Portugal is puzzling, considering the more pronounced impact of the Muslin rule in south Iberia and the widespread presence of African slaves throughout the country, and deserves further investigation.
Mitochondrial DNA affinities at the Atlantic fringe of Europe.
Gonzalez AM, Brehm A, Perez JA, Maca-Meyer N, Flores C, Cabrera VM.
Departamento de Genetica, Universidad de La Laguna, 38271 La Laguna, Tenerife, Spain.
[email protected]
Mitochondrial DNA analysis of Atlantic European samples has detected significant latitudinal clines for several clusters with Paleolithic (H) and Neolithic (J, U4, U5a1, and U5a1a) coalescence ages in Europe. These gradients may be explained as the result of Neolithic influence on a rather homogeneous Paleolithic background. There is also evidence that some Neolithic clusters reached this border by a continental route (J, J1, J1a, U5a1, and U5a1a), whereas others (J2) did so through the Mediterranean coast.
An important gene flow from Africa was detected in the Atlantic Iberia. Specific sub-Saharan lineages appeared mainly restricted to southern Portugal, and could be attributed to historic Black slave trade in the area and to a probable Saharan Neolithic influence. In fact, U6 haplotypes of specific North African origin have only been detected in the Iberian peninsula northwards from central Portugal. Based on this peculiar distribution and the high diversity pi value (0.014 +/- 0.001) in this area compared to North Africa (0.006 +/- 0.001), we reject the proposal that only historic events such as the Moslem occupation are the main cause of this gene flow, and instead propose a pre-Neolithic origin for it.
The haplogroup frequencies and sample sizes for the populations analyzed are given in Table 1. The haplotype with the reference sequence (CRS, Anderson et al., 1981) is the most abundant haplotype in all samples, although values range from 11.7% in northwest Africa to 21.7% in north Portugal.
As expected, sub-Saharan African influence, represented by haplotypes classified in L and Ml clusters, is important in northwest Africa (26.1%) but negligible in Europe, with the exception of south Portugal (11.7%).
On the other hand, subhaplogroup U6, of North African origin (Rando et al., 1998), has a local presence in Europe, being detected only in northwest Iberian Peninsula. The differential geographic distributions of these sub-Saharan African and northwest African haplogroups in the Iberian Peninsula are statistically significant: L and Ml clusters are more abundant in south Portugal (x = 9.81; P < 0.01), and U6 in northern areas (x = 5.83; P < 0.05).
Cluster U5, with coalescence ages in the early Upper Paleolithic, and a probable European origin (Richards et a!, 2000) reaches its highest frequencies for its ancestral motives in Britain (x = 11.74; P < 0.001) when compared to other continental areas such as Scandinavia, Germany, France, and the Iberian Peninsula.
With respect to northwest Africa, the geographically localized distribution of matches and haplotypes of sub-Saharan African and northwest African origin in the Iberian Peninsula is noteworthy. This distribution cannot be totally explained by a historic genetic influence from the Moslem occupation (Pereira et. al., 2000). During that time, the haplotype composition of northwest Africa had to be similar to that of the present, and for this reason, sub-Saharan African L and northwest African U6 haplotypes should be uniformly distributed in the Iberian peninsula.
However, with respect to the sub-Saharan Africa lineages, the recent history of the Black slave trade carried out by the Portuguese (mainly in the 15th and 16th centuries), with a well-documented import in southern Portugal (Godinho, 1983), could also be a plausible alternative to explain the presence of these African haplotypes in this region. (Pereira et al 2000) To test this possibility we compared the proportion of sub-Saharan Africa haplotype matches between the Iberian Peninsula and northwest Africa (0.75%) with those of the Iberian Peninsula and a sample of sub-Saharan Africans from the Gulf of Guinea.
These results suggest that, although both prehistoric and historical influences likely contributed to the sub-Saharan African haplotype pool present in the Iberian peninsula, the former seems to be more important.
Our results are in agreement with the gene flow (19.5%) from northwest Africa to the Iberian Peninsula estimated in a recent study of variation in the autosomic CD4 locus (Flores et al., 2000b), and with the evidence of northwest African male input in Iberia calculated at around 20%, using the relative frequency of northwest African Y-chromosome-specific markers in Iberian samples (Flores et al, 2000a).
Furthermore, our results clearly reinforce, extend, and clarify the preliminary clues of an important mtDNA contribution from northwest Africa into the Iberian Peninsula (Côrte-Real et al., 1996; Rando et al., 1998; Flores et al., 2000a; Rocha et al., 1999). On the basis of the Lib frequencies detected in Spanish and Portuguese samples (2—3%) and those found in western Africa (10-30%), a significant influence (at least 10%) of North Africans in have reached the Iberian Peninsula gene pool has also been admitted (Rocha et al., 1999).
In a similar way, and discarding possible genetic drift effects, our own data allow us to make minimal estimates of the maternal African pre Neolithic, and/or recent slave trade input into Iberia. For the former, we consider only the mean value of the U6 frequency in northern African populations, excluding Saharans, Tuareg, and Mauritanians (16%), as the pre-Neolithic frequency in that area, and the present frequency in the whole Iberian Peninsula (2.3%) as the result of the northwest African gene flow at that time.
The value obtained (14%) could be as high as 35% using the data of Côrte-Real et al. (1996), or 27% with our north Portugal sample.
In the same vein, the Saharan Neolithic gene flow can be estimated as 13%, taking the actual frequencies for the sub-Saharan African haplogroups (51%) in southern northwest African samples (Tuareg, Saharans, and Mauritanians) as the frequency of the African Neolithic, and that of the Iberian Peninsula (6.8%) as the result of the putative Neolithic maternal gene flow. This value could rise to 23% when only south Portugal is taken into account.
However, if we admit a recent 10% of slave trade input into this region, as historically documented (Godinho, 1983), 13% would be left for the putative Saharan Neolithic gene flow.
http://goliath.ecnext.com/coms2/gi_0...in-Iberia.html
African female heritage in Iberia: a reassessment of mtDNA lineage distribution in present times.
Publication: Human Biology
Publication Date: 01-APR-05
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Sub-Saharan African Influence. The mean frequency for the sequences belonging to superhaplogroup L, typical for sub-Saharan populations, reaches 3.83% ([+ or -]0.59%) in Iberia, representing 40 sequences in the total sample of 1,045 individuals.
The frequency is clearly higher (Figure 1) in Portugal (32 sequences in 549 individuals; 5.83%) than in Spain (8 out of 496; 1.61%) and without parallel in the rest of Europe. Furthermore, in western Iberia, increasing frequencies are observed for Galicia and northern Portugal (3.26% and 3.21%, respectively--a value similar to the one found in the rest of Spain) through the center (5.02%) and to the south (11.38%). The overall geographic Iberian heterogeneity is highly significant (p = 0.0003 in the chi-square for the 2 X 9 contingency table), as is the heterogeneity for the four western populations (p = 0.0110).
This pattern is also consistent with historical reports referring to a predominant introduction of slaves in southern Portugal (Lahon 1999).
What a great scholar you are...:bored:
