Periodic Reporting for period 4 - BantuFirst (The First Bantu Speakers South of the Rainforest: A Cross-Disciplinary Approach to Human Migration, Language Spread, Climate Change and Early Farming in Late Holocene Central Africa)
Reporting period: 2022-07-01 to 2023-12-31
The Bantu Expansion is unique among ancient dispersals of peoples and languages due to its combination of high amplitude, rapid pace and adaptation to multiple ecozones. The spread of Bantu-speaking people from a homeland region on the border between Nigeria and Cameroon towards Eastern and Southern Africa starting some 4000 to 5000 years ago had a momentous impact on the continent’s linguistic, demographic and cultural landscape. The approximately 550 Bantu languages spoken today constitute Africa’s largest language family, and the gene pool of Bantu-speaking communities throughout sub-Saharan Africa still contain a dominant ancestral West African component. In the Congo rainforest of Central Africa, the intensification of settlements from the first millennium BC with pottery and large refuse pits, and with evidence of cultivation, husbandry, and later on metallurgy points to development of a more sedentary lifestyle contrasting to that of previous hunter-gatherers. The spread of this new material culture is generally viewed as the archaeological backdrop of the area’s penetration by the first Bantu speakers. Debate continues on the driving forces behind the Bantu Expansion. Two widely accepted paradigms are that [1] it was a single migratory macro-event; and [2] it was a farming/language dispersal. Sadly, these are based on very limited empirical evidence. BantuFirst was therefore conceived as a cross-disciplinary research project aiming at transforming our thinking on the Bantu Expansion by collecting new empirical evidence to gain a better understanding of the interconnections between human migration, language spread, climate change and early farming in Late Holocene Central Africa. Together they carried out evidence-based frontier research on the first Bantu-speaking settlements south of the Congo rainforest in parts of the Democratic Republic of Congo, the Republic of Congo and Angola that are as yet still unexplored by archaeologists.
Our historical linguists focused on one branch of the Bantu family, i.e. ‘West-Coastal’, and aimed at a better understanding of (i) its center of expansion and initial divergence; (ii) subsequent processes of linguistic convergence due to contact among Bantu languages and with extinct non-Bantu languages; and (iii) what reconstructed WCB vocabulary can tell us about ancestral lifeways.
Our archaeologists conducted eight field seasons in DRC's Kinshasa, Kwilu, Mai-Ndombe, and Kongo-Central provinces. Large-scale survey and excavations resulted in more than 180 new sites starting from the Middle Stone Age (~300ka BP). Excavations at 31 of these locations has produced voluminous new information on the changing material culture, subsistence practices, and settlement patterns, as well as their evolving palaeoenvironmental conditions. This data also includes more than 100 new carbon-14 dates, extending from 30ka – 400 BP.
As for evolutionary genetics, more 1300 new modern DNA samples from the DRC and Congo were collected in the course of the BantuFirst project, including from among several relic hunter-gatherer communities. So far, only 300 samples collected in 2019 have been published. More data will be included in future publications.
Our archaeologists conducted eight field seasons in DRC's Kinshasa, Kwilu, Mai-Ndombe, and Kongo-Central provinces. Large-scale survey and excavations resulted in more than 180 new sites starting from the Middle Stone Age (~300ka BP). Excavations at 31 of these locations has produced voluminous new information on the changing material culture, subsistence practices, and settlement patterns, as well as their evolving palaeoenvironmental conditions. This data also includes more than 100 new carbon-14 dates, extending from 30ka – 400 BP.
As for evolutionary genetics, more 1300 new modern DNA samples from the DRC and Congo were collected in the course of the BantuFirst project, including from among several relic hunter-gatherer communities. So far, only 300 samples collected in 2019 have been published. More data will be included in future publications.
The project's main objectives were:
[1] Uncovering the archaeological signature of the first Bantu speakers south of the rainforest in the West-Coastal Bantu (WCB) homeland straddling the Congo River north of Brazzaville and Kinshasa around 2,500 BP.
[2] Determining (a) whether an earlier expansion of Bantu speakers took place along the Atlantic coastline, (b) whether their languages disappeared due to the later spread of WCB, and (c) whether they left substrate traces still detectable in WCB.
[3] Establishing (a) whether new settlements interacted with autochthonous hunter-gatherers and (b) whether signs of this contact are still retrievable in archaeology, linguistics, and genetics.
[4] Gaining insights on the subsistence economies of the first settlers in the study area.
[5] Reconstructing (a) the impact of vegetation dynamics and (b) whether major changes in the natural environment were primarily climate-induced or anthropogenic.
As for [1], following our 2019 lexicon-based phylogeny, we developed a new hypothesis on the WCB homeland, i.e. significantly further east, more precisely between the Kasai and its Kamtsha affluent in the Kwilu province (DRC). After initial archaeological fieldwork near the Bateke Plateau, excavations happened further east from 2019 onwards, i.e. around Idiofa and Kikwit and along Kwilu-Kwa-Kasai-Kamtsha-Loange Rivers, all areas previously unexplored. Two major westward expansions out of the Lower Kasai region towards the Atlantic coast must have started relatively soon after the initial settlement of WCB speakers south of the Kasai River, namely during the Early Iron Age (ca. 400 BCE-700 CE).
As for [2], our historical-linguistic research has confirmed that the Atlantic Coast is an area where early WCB speakers settled as the latest. Only one archaeological mission happened in the Lower Congo region. Neither this fieldwork nor earlier KongoKing research has yielded evidence for settlement preceding the CE.
As for [3], the most straightforward evidence for contact and admixture with local Central-African hunter-gatherer populations comes from genetic data. No clear archaeological evidence for contact between local Central-African populations and Bantu-speaking settlers has been found, but several sites excavated by our team contribute to a better understanding of the Late Stone Age region, especially Mitshikila and Mukila. Our diachronic phonological research on substrate interference shows that the WCB-speaking populations who had remained in the homeland area of the Lower Kasai engaged in intensive language contact both during the Early Iron Age (ca. 400 BCE-700 CE) and the Late Iron Age (ca. 1400-1900 CE), involving both local hunter-gatherer groups and populations with more northern roots speaking non-Bantu languages.
As for [4], we documented around 1400 BP a mixed subsistence economy with hunting, fishing, and collecting crabs, bivalve, and gastropods on the Atlantic coast. More archaeobotanical data will be published in future publications. The possibility to reconstruct specific terms of several domesticated plants and animals in the most recent ancestor of WCB suggests that the earliest WCB speakers had become proficient food producers. Nevertheless, reconstructable vocabulary for wild plants and animals shows that farming and husbandry coexisted with collecting and hunting in their mixed subsistence economy.
As for [5], palaeoecological data from around Idiofa, i.e. carbon isotopes and phytoliths, show that the earliest settlers around Idiofa in the 2nd century BCE did not settle in open grasslands but in a habitat where the forests had started to undergo climate-induced degradation before their arrival. Reconstructable wild flora and fauna lexicon also suggests that the earliest WCB speakers operated in a tropical moist lowland forest environment, a habitat that is significantly distinct from the one prevailing today south of the Kasai River. Analyses on charcoal from the Lower Congo suggest that the earliest pottery producers at Muanda on the Atlantic Coast lived in a wooded savanna environment, with mangrove and gallery forests nearby.
[1] Uncovering the archaeological signature of the first Bantu speakers south of the rainforest in the West-Coastal Bantu (WCB) homeland straddling the Congo River north of Brazzaville and Kinshasa around 2,500 BP.
[2] Determining (a) whether an earlier expansion of Bantu speakers took place along the Atlantic coastline, (b) whether their languages disappeared due to the later spread of WCB, and (c) whether they left substrate traces still detectable in WCB.
[3] Establishing (a) whether new settlements interacted with autochthonous hunter-gatherers and (b) whether signs of this contact are still retrievable in archaeology, linguistics, and genetics.
[4] Gaining insights on the subsistence economies of the first settlers in the study area.
[5] Reconstructing (a) the impact of vegetation dynamics and (b) whether major changes in the natural environment were primarily climate-induced or anthropogenic.
As for [1], following our 2019 lexicon-based phylogeny, we developed a new hypothesis on the WCB homeland, i.e. significantly further east, more precisely between the Kasai and its Kamtsha affluent in the Kwilu province (DRC). After initial archaeological fieldwork near the Bateke Plateau, excavations happened further east from 2019 onwards, i.e. around Idiofa and Kikwit and along Kwilu-Kwa-Kasai-Kamtsha-Loange Rivers, all areas previously unexplored. Two major westward expansions out of the Lower Kasai region towards the Atlantic coast must have started relatively soon after the initial settlement of WCB speakers south of the Kasai River, namely during the Early Iron Age (ca. 400 BCE-700 CE).
As for [2], our historical-linguistic research has confirmed that the Atlantic Coast is an area where early WCB speakers settled as the latest. Only one archaeological mission happened in the Lower Congo region. Neither this fieldwork nor earlier KongoKing research has yielded evidence for settlement preceding the CE.
As for [3], the most straightforward evidence for contact and admixture with local Central-African hunter-gatherer populations comes from genetic data. No clear archaeological evidence for contact between local Central-African populations and Bantu-speaking settlers has been found, but several sites excavated by our team contribute to a better understanding of the Late Stone Age region, especially Mitshikila and Mukila. Our diachronic phonological research on substrate interference shows that the WCB-speaking populations who had remained in the homeland area of the Lower Kasai engaged in intensive language contact both during the Early Iron Age (ca. 400 BCE-700 CE) and the Late Iron Age (ca. 1400-1900 CE), involving both local hunter-gatherer groups and populations with more northern roots speaking non-Bantu languages.
As for [4], we documented around 1400 BP a mixed subsistence economy with hunting, fishing, and collecting crabs, bivalve, and gastropods on the Atlantic coast. More archaeobotanical data will be published in future publications. The possibility to reconstruct specific terms of several domesticated plants and animals in the most recent ancestor of WCB suggests that the earliest WCB speakers had become proficient food producers. Nevertheless, reconstructable vocabulary for wild plants and animals shows that farming and husbandry coexisted with collecting and hunting in their mixed subsistence economy.
As for [5], palaeoecological data from around Idiofa, i.e. carbon isotopes and phytoliths, show that the earliest settlers around Idiofa in the 2nd century BCE did not settle in open grasslands but in a habitat where the forests had started to undergo climate-induced degradation before their arrival. Reconstructable wild flora and fauna lexicon also suggests that the earliest WCB speakers operated in a tropical moist lowland forest environment, a habitat that is significantly distinct from the one prevailing today south of the Kasai River. Analyses on charcoal from the Lower Congo suggest that the earliest pottery producers at Muanda on the Atlantic Coast lived in a wooded savanna environment, with mangrove and gallery forests nearby.