18 research outputs found
Ancestral Stories of Ghanaian Bimoba Reflect Millennia-Old Genetic Lineages
<div><p>Oral history and oral genealogies are mechanisms of collective memory and a main cultural heritage of many populations without a writing system. In the effort to analytically address the correspondence between genetic data and historical genealogies, anthropologists hypothesised that genealogies evolve through time, ultimately containing three parts: literal – where the most recent ancestry is truthfully represented; intended – where ancestry is inferred and reflects political relations among groups; and mythical – that does not represent current social reality. While numerous studies discuss oral genealogies, to our knowledge no genetic studies have been able to investigate to what extent genetic relatedness corresponds to the literal and intended parts of oral genealogies. We report on the correspondence between genetic data and oral genealogies among Bimoba males in a single village in North-Eastern Ghana. We compared the pairwise mismatch distribution of Y chromosome short tandem repeat (Y-STR) haplotypes among all lineages present in this village to the self-reported (oral) relatedness. We found that Bimoba are able to correctly identify unrelated individuals in 92% of the cases. In contrast, they are able to correctly identify related individuals only in 38% of the cases, which can be explained by three processes: (1) the compression of genealogies, leading to increasing inaccuracy with increasing genealogical distance, (2) inclusions into the lineage from intended relations such as clan co-option or adoptions, and (3) false paternities, which in this study were found to have a minor effect on the correspondence between genetic data and oral genealogies. In addition, we observed that 70% of unrelated pairs have from six to eight Y-STR differences, a diversification peak which we attribute to an ancient West African expansion dating around 9454 years ago. We conclude that, despite all caveats, oral genealogies are reflecting ancient lineages more accurately than previously thought.</p></div
Evaluating self-declared ancestry of U.S. Americans with autosomal, Y-chromosomal and mitochondrial DNA
The current U.S. population represents an amalgam of individuals originating mainly from four continental regions (Africa, Europe, Asia and America). To study the genetic ancestry and compare with self-declared ancestry we have analyzed paternally, maternally and bi-parentally inherited DNA markers sensitive for indicating continental genetic ancestry in all four major U.S. American groups. We found that self-declared U.S. Hispanics and U.S. African Americans tend to show variable degrees of continental genetic admixture among the three genetic systems, with evidence for a marked sex-biased admixture history. Moreover, for these two groups we observed significant regional variation across the country in genetic admixture. In contrast, self-declared U.S. European and U.S. Asian Americans were genetically more homogeneous at the continental ancestry level. Two autosomal ancestry-sensitive markers located in skin pigmentation candidate genes showed significant differences in self-declared U.S. African Americans or U.S. European Americans, relative to their assumed parental populations from Africa or Europe. This provides genetic support for the importance of skin color in the complex process of ancestry identification
Correction to: The Dutch Y-chromosomal landscape (European Journal of Human Genetics, (2019), 10.1038/s41431-019-0496-0)
Due to a misunderstanding between the authors, Dr. Lao’s present address was incomplete when the paper was published. The correct present address should read: CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, and Universitat Pompeu Fabra (UPF), Barcelona, Spain
Mismatch distribution of Y-STR haplotypes in a Bimoba village.
<p>The mismatch distribution of the number of Y-STR differences in all pairs of 255 men, expressed as the percentage of observed pairs (32385 pairs). A higher number of Y-STR differences indicates a longer time to the most recent common ancestor.</p
Oral genealogies of a Bimoba village.
<p>A schematic model of the collected genealogies and the social structure of 255 Bimoba men, with a summary of their genealogical and genetic data. The theoretical anthropologic classification of oral genealogies is depicted on the left. Historians and anthropologists distinct three levels in oral genealogies: a literal level that represents the immediate past, an intended level that contains information of the social relations, and a mythical level where a direct relation is unclear. The family units are organized into six clans. Two pairs of clans are joined by a reported common male ancestor.</p
A Linguistically Informed Autosomal STR Survey of Human Populations Residing in the Greater Himalayan Region
The greater Himalayan region demarcates two of the most prominent linguistic phyla in Asia: Tibeto-Burman and IndoEuropean. Previous genetic surveys, mainly using Y-chromosome polymorphisms and/or mitochondrial DNA polymorphisms suggested a substantially reduced geneflow between populations belonging to these two phyla. These studies, however, have mainly focussed on populations residing far to the north and/or south of this mountain range, and have not been able to study geneflow patterns within the greater Himalayan region itself. We now report a detailed, linguistically informed, genetic survey of Tibeto-Burman and Indo-European speakers from the Himalayan countries Nepal and Bhutan based on autosomal microsatellite markers and compare these populations with surrounding regions. The genetic differentiation between populations within the Himalayas seems to be much higher than between populations in the neighbouring countries. We also observe a remarkable genetic differentiation between the Tibeto-Burman speaking populations on the one hand and Indo-European speaking populations on the other, suggesting that language and geography have played an equally large role in defining the genetic composition of present-day populations within the Himalayas
Summary of Mantel tests in zt.
<p>The results of the simple Mantel tests are shown above the diagonal; the results of the partial Mantel tests are shown below the diagonal. r<sub>p</sub>: correlation coefficient for Mantel test on population level with 100 thousand randomisations, r<sub>i</sub>: correlation coefficient for Mantel test on individual level with 10 thousand randomisations. Corresponding p-values are shown between brackets.</p
A collaborative EDNAP exercise on SNaPshot™-based mtDNA control region typing
A collaborative European DNA Profiling (EDNAP) Group exercise was undertaken to assess the performance of an earlier described SNaPshot™-based screening assay (denoted mini-mtSNaPshot) (Weiler et al., 2016) [1] that targets 18 single nucleotide polymorphism (SNP) positions in the mitochondrial (mt) DNA control region and allows for discrimination of major European mtDNA haplogroups. Besides the organising laboratory, 14 forensic genetics laboratories were involved in the analysis of 13 samples, which were centrally prepared and thoroughly tested prior to shipment. The samples had a variable complexity and comprised straightforward single-source samples, samples with dropout or altered peak sizing, a point heteroplasmy and two-component mixtures resulting in one to five bi-allelic calls. The overall success rate in obtaining useful results was high (97.6%) given that some of the participating laboratories had no previous experience with the typing technology and/or mtDNA analysis. The majority of the participants proceeded to haplotype inference to assess the feasibility of assigning a haplogroup and checking phylogenetic consistency when only 18 SNPs are typed. To mimic casework procedures, the participants compared the SNP typing data of all 13 samples to a set of eight mtDNA reference profiles that were described according to standard nomenclature (Parson et al., 2014) [2], and indicated whether these references matched each sample or not. Incorrect scorings were obtained for 2% of the comparisons and derived from a subset of the participants, indicating a need for training and guidelines regarding mini-mtSNaPshot data interpretation
Summary of Admixture analysis.
<p>IE: Indo-European, TB: Tibeto-Burman, DR: Dravidian, AL: Altaic.</p