Ancestral Stories of Ghanaian Bimoba Reflect Millennia-Old Genetic Lineages

Abstract

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.

A Phylogenetic Comparative Study of Bantu Kinship Terminology Finds Limited Support for Its Co-Evolution with Social Organisation

“…Amongst the historical Bantu chiefdoms that make up the sample of this study, kinship rules and social law were one and the same. In fact, kinship laws were so well respected that they have been found to be reflected in the genetic patterning of sub-Saharan African populations, with cultural rules showing to be a good predictor for explaining genetic variation across clan groups [ 74 ].…”

Forensic DNA analysis and database governance in Ghana

“…To calculate a more accurate random match probability of profiles generated from crime scene traces and subject samples, forensic DNA scientists must have access to a representative allele frequency database (M'charek, 2000). In our literature search, we found six publications related to the STR allele frequencies, SNP and mtDNA haplotype frequencies of ethnic groups from Ghana (Fendt et al, 2012;Kofi et al, 2020;Poetsch et al, 2011;Sanchez-Faddeev et al, 2013b, 2013aWepeba, Iyengar, and Goodwin, 2019). These studies provide information that can be used for calculations in forensic casework to determine the significance of DNA evidence.…”

Heterozygous 21 STR loci and triplet alleles observed in population genetic analysis of the GlobalFiler STR loci in the Ghanaian population

“…In Type 1, the sum of the intensities of two alleles equal the third, while the intensities of all the three are equal in Type 2 [3] Little forensic genetic research has been conducted in Ghana. Previous studies have investigated the X-chromosome involving 182 Ewes [6], mitochondrial DNA analysis was carried out from 193 Akans in the Ashanti region [7], and mitochondrial, Y-chromosome and autosomal STR analysis of the Bimoba clan in North Eastern Ghana [8]. An additional study was conducted involving 255 males from six clans in the Bimoba village to investigate self-reported oral pedigrees [9] This study, with sample representation from the four most populous groups in Ghana, surveyed the genetic diversity of Ghana using the GlobalFiler™ Amplification Kit.…”