Internal diversification of non‐Sub‐Saharan haplogroups in Sahelian populations and the spread of pastoralism beyond the Sahara
July 2017 American Journal of Physical Anthropology 164(2) DOI:10.1002/ajpa.23285 Authors: Iva Kulichová, Verónica Fernandes, Alioune Deme, Jana Nováčková, Vlastimil Stenzl, Andrea Novelletto, Luísa Pereira, Viktor Černý
Abstract and Figures Background: Today, African pastoralists are found mainly in the Sahel/Savannah belt spanning 6,000 km from west to east, flanked by the Sahara to the north and tropical rainforests to the south. The most significant group among them are the Fulani who not only keep cattle breeds of possible West Eurasian ancestry, but form themselves a gene pool containing some paternally and maternally-transmitted West Eurasian haplogroups. Materials and methods: We generated complete sequences for 33 mitogenomes belonging to haplogroups H1 and U5 (23 and 10, respectively), and genotyped 16 STRs in 65 Y chromosomes belonging to haplogroup R1b-V88. Results: We show that age estimates of the maternal lineage H1cb1, occurring almost exclusively in the Fulani, point to the time when the first cattle herders settled the Sahel/Savannah belt. Similar age estimates were obtained for paternal lineage R1b-V88, which occurs today in the Fulani but also in other, mostly pastoral populations. Maternal clade U5b1b1b, reported earlier in the Berbers, shows a shallower age, suggesting another possibly independent input into the Sahelian pastoralist gene pool. Conclusions: Despite the fact that animal domestication originated in the Near East ∼ 10 ka, and that it was from there that animals such as sheep, goats as well as cattle were introduced into Northeast Africa soon thereafter, contemporary cattle keepers in the Sahel/Savannah belt show uniparental genetic affinities that suggest the possibility of an ancient contact with an additional ancestral population of western Mediterranean ancestry.
Sequencing of the HVS-1 (and in several cases of the HVS-2) in 2,129 mtDNA samples from Sahelian populations revealed a clear predominance (82.8%) of sub-Saharan haplotypes belonging to haplogroupsL1–6. The remaining haplotypes (17.2%) were classified as non-L, a meta-group which includes haplotypes of West Eurasian ancestry. We used a chi-square test to examine whether these two kinds of sequences (L-type and non-L-type) were evenly distributed between nomadic pastoralists and sedentary farmers, and found that the observed difference (higher frequency of non-L among pastoralists) falls short of statistical significance (p50.065). However, haplogroups H1cb and U5b both occurred significantly more often in the Fulani pastoralists than other populations (chi-square tests, p-0.05), so we decided to focus on these samples.
The phylogenetic reconstruction of Sahelian R1b-V88 Y-STR haplotypes is shown in Figure 5, and its general structure suggests that a relevant part of the haplotypic diversity of this clade remains unsampled. A tentative reconstruction of the ancestral haplotype(s) for the Sahel can be obtained by inference and comparison with the data by Cruciani et al. (2010).
Pinpointing the geographic origin of the U5b1b1b haplogroup is amore difficult task. The parental lineage U5b1b1, aged 9 ka, is highly dispersed from the Saami in Scandinavia to Berbers in North Africa, indicating the Franco-Cantabrian refuge area as the most parsimonious source of late-glacial expansions of hunter-gatherers repopulating the entire region heading both north and south (Achilli et al., 2005). The most probable hypothesis is, therefore, that the U5b1b1b found in the Fulani today is derived from North African U5b1b1 ancestors. Both H1cb and U5b1b1b seem to be excellent markers of European - and not Near Eastern - ancestry inputs into the contemporary Fulani population
Pinpointing the geographic origin of the U5b1b1b haplogroup is amore difficult task. The parental lineage U5b1b1, aged 9 ka, is highly dispersed from the Saami in Scandinavia to Berbers in North Africa, indicating the Franco-Cantabrian refuge area as the most parsimonious source of late-glacial expansions of hunter-gatherers repopulating the entire region heading both north and south (Achilli et al., 2005). The most probable hypothesis is, therefore, that the U5b1b1b found in the Fulani today is derived from North African U5b1b1 ancestors. Both H1cb and U5b1b1b seem to be excellent markers of European - and not Near Eastern - ancestry inputs into the contemporary Fulani population
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I've mentioned this in older threads but not devoted a thread to it. and did not have access to the whole article back then. Also I have added some of the charts (save the image for future reference)
This article does not give a breakdown on their African DNA. It's focused on the non-African
As for R-V88 for Fulani look at the chart, there are many Fulani groups the sample size of each is the second sample size column "n y chr" Some are 1 in 20 ish, but it varies That is 5%, not so much, the red on the pie chart above (see 3 letter abbreviations on table and relate to pie chart)
This excludes Cameroon where the much higher levels of R-V88 are found U5b/H1 mitochondrial , yellow slices in the gray pie chart
Also look at some of the other groups on that table, there's Beja, Nubians, Tuareg and others
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2017^
More recently I made a thread on on the below article. Here are the Fulani extracts:
quote:
Demographic history and admixture dynamics in African Sahelian populations Viktor Černý, Cesar Fortes-Lima, Petr Tříska Author Notes Human Molecular Genetics, Volume 30, Issue R1, 1 March 2021,
In the western part of the Sahel, our genetic studies of Fulani pastoralists have shown that they mainly have haplogroups of western African ancestry; however, some northern African (36,39) and east African ancestry (30) were also detected. In the eastern part of the Sahel, we investigated the genetic patterns in Arab pastoralists, and our results of both uniparental markers supported the possibility of the earlier-mentioned Baggarization process (32), besides biological contacts between the Fulani and Arabs must have been rather infrequent. This is also evident from the investigation of lactase persistence alleles described later (33,42,43).
Using genetic information of a hypervariable region in the mtDNA known as the D-loop, we tested migration events between pastoralists and farmers in both the eastern and western parts of the Sahel/Savannah belt and found different trends in the Fulani and the Arabs (31). In the eastern part of Sahel, the inferred best-fitting model indicated a more intensive gene flow between the two groups, especially in the direction from sub-Saharan farmers to Arabic-speaking pastoralists. Limited gene flow took place in the west as well, but it was more pronounced only among some Fulani sub-populations (31). In addition, asymmetric gene flow, that is, differences in the migration pattern of male versus female subpopulations, was observed as well (32). It has also been established that factors other than the mode of subsistence help account for the population structure across the Sahel belt, whereas for pastoralists, the main factor is their linguistic affiliation, and for farmers, it is their geographical location.
The Fulani are a large and widely dispersed population of both nomadic herders and sedentary farmers, who speak a Niger-Congo language and live in the Sahel/Savannah belt. Nowadays, they are scattered all the way from Senegal in the west to the Blue Nile area of Sudan in the east. More recently, a genome-wide study of a Fulani community from Burkina Faso inferred two major admixture events in this group, dating to ~1800 and 300 ya (50). The first admixture event took place between west African ancestors of the Fulani and ancestral north African nomadic groups (see results for ‘Burkina_Faso_Fulani_V’ in Fig. 2B), which probably coincided with a change of lifestyle and adaptation to milk consumption and subsequently led to Fulani expansion throughout the Sahel/Savannah belt. The timing also coincides with the beginnings of pastoralism in western Africa, especially in northern Burkina Faso, which archaeozoological evidence dates to ~ 2 kya (57). The second admixture event, relatively recent, inferred a source from southwestern Europe, which suggests either a gene flow between the Fulani and northern African groups, who carry considerable admixture proportions from Europeans due to trans-Gibraltar gene flow (51), or the influence of European colonial expansion into Africa, both implying maritime travels (50).
Future research involving numerous Fulani and Arab communities from different regions would help us to further investigate and reconstruct more complex admixture scenarios among these groups, and to better understand the factors that led to extensive spread of these groups across the Sahel/Savannah belt.
Because of the historical admixture events, Fulani genomic diversity is a mosaic of African and Eurasian haplotypes (30,44). In genomic regions where a particular haplotype provides an evolutionary advantage, such as the LCT region, the ratio between African and Eurasian haplotypes in the population is skewed due to selective pressures, which increased the frequency of the advantageous haplotype. As a result, the European LP haplotype is present in approximately one half of Fulani from Ziniaré (Burkina Faso) (50), which is significantly higher than the genome-wide average amount of European ancestry in the Fulani population in general (33).
The ability to detect bitter compounds in food is mediated by bitter taste receptors encoded by a wide range of genes belonging to the TAS2R family. Because bitter taste often indicates the presence of potentially harmful substances, such as alkaloids, the ability to detect bitter taste is considered a protective evolutionary feature. A strong signature of positive selection on the TAS2R16 gene has been reported not only in Eurasian populations (67) but also in east African populations and in Fulani from Cameroon (68). A special role of TAS2R receptors in the Fulani is also reflected in an enrichment of Eurasian haplotypes in the TAS2R genes on chromosome 12 (44), although the driver of the natural selection remains unclear. One possible explanation is that during particular rituals (69,70), the Fulani consume substances containing various alkaloids and TAS2R receptors might play a role in the process of ingestion of these potions (44).
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