Ancient West African foragers in the context of African population history.

Our knowledge of ancient human population structure in sub-Saharan Africa, particularly prior to the advent of food production, remains limited. Here we report genome-wide DNA data from four children-two of whom were buried approximately 8,000 years ago and two 3,000 years ago-from Shum Laka (Cameroon), one of the earliest known archaeological sites within the probable homeland of the Bantu language group1-11. One individual carried the deeply divergent Y chromosome haplogroup A00, which today is found almost exclusively in the same region12,13. However, the genome-wide ancestry profiles of all four individuals are most similar to those of present-day hunter-gatherers from western Central Africa, which implies that populations in western Cameroon today-as well as speakers of Bantu languages from across the continent-are not descended substantially from the population represented by these four people. We infer an Africa-wide phylogeny that features widespread admixture and three prominent radiations, including one that gave rise to at least four major lineages deep in the history of modern humans.

Historical human remains identification through maternal and paternal genetic signatures in a founder population with extensive genealogical record.

OBJECTIVES: We describe a method to identify human remains excavated from unmarked graves in historical Québec cemeteries by combining parental-lineage genetic markers with the whole-population genealogy of Québec contained in the BALSAC database. MATERIALS AND METHODS: The remains of six men were exhumed from four historical cemeteries in the province of Québec, Canada. DNA was extracted from the remains and genotyped to reveal their mitochondrial and Y-chromosome haplotypes, which were compared to a collection of haplotypes of genealogically-anchored modern volunteers. Maternal and paternal genealogies were searched in the BALSAC genealogical record for parental couples matching the mitochondrial and the Y-chromosome haplotypic signatures, to identify candidate sons from whom the remains could have originated. RESULTS: Analysis of the matching genealogies identified the parents of one man inhumed in the cemetery of the investigated parish during its operating time. The candidate individual died in 1833 at the age of 58, a plausible age at death in light of osteological analysis of the remains. DISCUSSION: This study demonstrates the promising potential of coupling genetic information from living individuals to genealogical data in BALSAC to identify historical human remains. If genetic coverage is increased, the genealogical information in BALSAC could enable the identification of 87% of the men (n = 178,435) married in Québec before 1850, with high discriminatory power in most cases since >75% of the parental couples have unique biparental signatures in most regions. Genotyping and identifying Québec's historical human remains are a key to reconstructing the genomes of the founders of Québec and reinhuming archeological remains with a marked grave.

Investigating temporal bone variation of colonial populations from St-Lawrence Valley, Quebec: A 3D geometric morphometric approach.

OBJECTIVES: In Quebec, genetic and genealogical research are used to document migratory events and family structures since colonial times, because bioarchaeological analysis is limited by poor skeletal preservation. This article aims to fill this gap by exploring past population structure in the St-Lawrence Valley from the French (1683-1760) and British (1760-1867) regimes using morphological variation of well-preserved temporal bones. MATERIALS AND METHODS: 3D geometric morphometrics shape data from seven populations (five Catholics of French descent and two Protestants of British descent; n = 214) were collected from temporal bones. Using Procrustes distances and both MANOVA and Discriminant Function Analysis, morphological differences were measured to calculate affinities patterns among populations. Shape variations were explored with between-group analysis, Mahalanobis distances and quantified by means of Fst estimates using Relethford-Blangero analysis. RESULTS: Despite strong affinities between all Catholic cemeteries, all show divergent morphological regional diversity -especially Montreal and the fortified villages dedicated to its defense. Montreal exhibits low increase in morphological variance over three centuries. As our results show no morphological differences between the Catholic and the Protestant cemeteries in Montreal, this fact may highlight the potential presence of Irish or admixed individuals in Montreal cemeteries after the British takeover. DISCUSSION: Patterns of morphological diversity highlighted that French colonists did not equally contribute to the descendant populations as reflected by significant interregional variation. Although historical records show that French and English-speaking populations did not tend to admix, morphological affinities between Protestants and Catholics in the beginning of the industrial era in Montreal could reflect the genetic contribution of Catholic Irish migrants. RESEARCH HIGHLIGHTS: All Catholic cemeteries display distinct morphologies, highlighting differential contributions from French colonists and founder effects, which have increased regional differences. Montreal Catholic (French descent) and Protestant (English colonists) cemeteries show significant morphological affinities at the beginning of the industrial era. The Irish migration following the British conquest may explain morphological similarities observed between Catholic and Protestant cemeteries.

OBJECTIFS: Au Québec, les phases de peuplement suivant l'arrivée des premiers colons européens ont presque été exclusivement documentées par des recherches génétiques et généalogiques. Les analyses bioarchéologiques sont limitées par l'important état de fragmentation des collections. L'étude de la variation morphologique de l'os temporal, particulièrement bien conservé, permettrait d'explorer l'histoire des populations de la vallée du Saint-Laurent, du régime français (1683-1760) au régime britannique (1760-1878). MATÉRIELS ET MÉTHODES: Un total de 214 os temporaux issus de sept cimetières catholiques (ascendance française) et protestants (ascendance britannique) a été modélisé en 3D et analysé par morphométrie géométrique. Des analyses de/par distance Procruste couplées avec une analyse discriminante et une MANOVA ont été utilisées pour évaluer les différences et affinités morphologiques entre les cimetières. Les fluctuations morphologiques ont été étudiées à l'aide d'une analyse de distances de Mahalanobis et quantifiées au moyen d'estimations Fst en utilisant l'analyse de Relethford-Blangero. RÉSULTATS: Malgré une forte affinité entre tous les cimetières catholiques, ces derniers présentent également une diversité morphologique régionale divergente - en particulier Montréal et ses villages satellites fortifiés. Montréal présente une faible augmentation de la variance morphologique sur trois siècles. Nos résultats ne montrent pas de différences morphologiques entre les populations francophones et anglophones, ce qui pourrait refléter la présence d'Irlandais après la conquête britannique. DISCUSSION: Les modèles de diversité morphologique interrégionale démontrent que les colons français n'ont pas contribué de manière égale aux populations descendantes comme le démontre les différences morphologiques observés. Les affinités entre protestants et catholiques au début de l'ère industrielle à Montréal pourraient refléter les importantes vagues de migrations irlandaises et le potentiel métissage malgré des différences socio-culturelle importantes.

Heterogeneity in experiences of vitamin D deficiency in an early to mid-19th century population from Montreal, Quebec.

OBJECTIVE: To use the prevalence of prenatal/infancy interglobular dentine (IGD) as a proxy for suboptimal vitamin D status and explore its link to mortality, biological sex, cultural behaviours and environmental factors during the end of the pre-industrial/ beginning of the industrial period. MATERIALS: 50 skeletons from the St. Antoine cemetery (1799-1854), Montreal, Quebec with a well-preserved first mandibular molar. METHODS: Thin sections were prepared for histological examination of IGD in crown dentine. RESULTS: IGD prevalence was 74 % (37/50) and not significantly correlated statistically to sex and age-at-death. Most IGD occurred at birth and up to 3 years-old, six individuals were affected in utero, 54 % of the sample (27/50) presented longstanding IGD and six individuals displayed multiple IGD episodes. CONCLUSIONS: Prenatal IGD episodes revealed suboptimal maternal vitamin D levels, which, alongside a high frequency of IGD episodes around birth/from birth until a certain age, suggest cultural influences. Multiple and longstanding IGD episodes might also reflect suboptimal seasonal vitamin D attainment. SIGNIFICANCE: This study provides in-depth data on IGD within a relatively large archaeological North American sample, proving relevant to epidemiological studies on suboptimal vitamin status in 19th century Montreal. LIMITATIONS: The total number of IGD episodes is underestimated due to methodological biases; first-generation migrants in this study could not be identified and excluded from the sample. SUGGESTIONS FOR FURTHER RESEARCH: Use of a larger sample with a wider age-at-death range; further research on infants and children to investigate links between growth and lesion formation and visibility.

Investigating individual migration life histories: An isotopic case study from 17th to 18th century Nouvelle France.

OBJECTIVES: This isotopic study explores the mobility patterns of a growing urban population from Notre Dame's Catholic cemetery (1691-1796), located in Montreal (Canada). The site offers a unique opportunity to investigate early colonial settlement in Nouvelle France through individual life patterns. MATERIALS AND METHODS: Stable oxygen isotopic compositions (δ18O) were measured on the enamel of 32 individuals from the Notre Dame collection. Premolars and third molars were selected, as they reflected the δ18O of the drinking water during childhood (2.5-5.5 years) and pre-adulthood (9.5-15.5 years). Firstly, premolars from three children (4-8 years of age) allowed us to provide a mean δ18O for the water consumed locally (22.7 ± 1.0 ‰ vs. VSMOW). Then, our δ18O were compared with published data from various geographical regions in North America (Eastern Canada and the United States) and Europe (France and the British Isles) to highlight mobility patterns of each individual. RESULTS: Forty-eight percent of our sample (14 out of 29 individuals) did not reflect any long-distance mobility, as all their δ18O reflected Montreal's variation during their lifetime. The remaining (15 out of 29 individuals) experienced mobility within (n = 8) and outside (n = 7) North America and at different phases of their life (five at pre-adulthood, six at adulthood and four during both phases). Their migration patterns were analyzed according to age, sex, diet and possible ancestry in order to propose some "biographies." DISCUSSION: This study highlights high population diversity in early colonial Montreal. Historians wrote that the city was growing, not only with the arrival of Europeans (e.g., young male workers, sailors), but also other groups (e.g., Indigenous people, slaves from North America). Additional analyses (e.g., ancient DNA) will be needed to explore further this phenomenon.

The rachitic tooth: The use of radiographs as a screening technique.

This study investigates morphological changes in pulp chambers of living and archaeological individuals with past vitamin D deficiency. Living individuals (n=29), four with detailed medical and dental records and three groups of archaeological individuals (n=25) were radiographed; selected individuals were further evaluated histologically for the presence of incremental interglobular dentin (IIGD), indicative of deficiency (28 living; 17 archaeological). Measurements of pulp horns/chambers from radiographs were conducted to quantify morphological observations. One group had clear skeletal evidence of rickets from St. Matthew, Quebec (n=1) and St. Jacques, France (n=4); a second group had slight skeletal indicators from Bastion des Ursulines, Quebec (n=6); and a third group lacked both skeletal and radiological evidence of deficiency from St. Antoine (n=6) and Pointe-aux-Trembles (n=4). Results showed archaeological individuals with clear and slight skeletal evidence of past deficiency displayed constricted or chair shaped pulp horns. Living individuals with deficiency exhibited similar pulp chamber morphology. Radiographic pulp horn/chamber measurements corroborated morphological findings and significant differences were found in pulp horn/chamber measurements between those with and without deficiency. Results suggest that radiograph assessment of teeth can be used as a screening technique to elucidate patterns of deficiency and select individuals for microCT or histological assessment.

Morphometric cranial identity of prehistoric Malawians in the light of sub-Saharan African diversity.

Little has been described of the Holocene populations of South-Central Africa, despite the region demonstrating major subsistence shifts relating to dispersals of agriculturalists at least 2,000 years ago. Seven sites with associated human skeletal remains were selected. Hora, Chencherere, Fingura, and Mtuzi represent the Middle Holocene (2,000-5,000 years ago), and Phwadze, Mtemankhokwe, and Nkudzi Bay represent the Late Holocene and the arrival of agriculturalists between 500-2,000 years ago. Focusing on the identity of Hora and Chencherere specimens, two questions were addressed: are the various Holocene Malawians similar to each other, or do they suggest morphological change over time? What modern populations are closest to the prehistoric specimens? The archaeological sample was compared to modern sub-Saharan Africans from four regions, plus a historic Khoi-San foraging group. Factor analyses were performed in order to identify complex patterns of variation in metric traits of the skull. According to the results, prehistoric Malawians showed only slight differences between the Late and Middle Holocene, suggesting a population change without any major discontinuity. Later Stone Age skulls did not exclusively show similarities with the Khoi-San, as they frequently fit well within the variation of modern Bantu-speaking groups, especially West-Central Africa. Therefore, we reject the hypothesis that Middle Holocene South-Central Africans have an exclusively Khoi-San ancestry, and support an alternative hypothesis that both Middle and Late Holocene groups share a common biological heritage originating in West-Central Africa in earlier times.