RESUMO
We assembled genome-wide data from 16 prehistoric Africans. We show that the anciently divergent lineage that comprises the primary ancestry of the southern African San had a wider distribution in the past, contributing approximately two-thirds of the ancestry of Malawi hunter-gatherers â¼8,100-2,500 years ago and approximately one-third of the ancestry of Tanzanian hunter-gatherers â¼1,400 years ago. We document how the spread of farmers from western Africa involved complete replacement of local hunter-gatherers in some regions, and we track the spread of herders by showing that the population of a â¼3,100-year-old pastoralist from Tanzania contributed ancestry to people from northeastern to southern Africa, including a â¼1,200-year-old southern African pastoralist. The deepest diversifications of African lineages were complex, involving either repeated gene flow among geographically disparate groups or a lineage more deeply diverging than that of the San contributing more to some western African populations than to others. We finally leverage ancient genomes to document episodes of natural selection in southern African populations. PAPERCLIP.
Assuntos
População Negra/genética , Genoma Humano , África , Osso e Ossos/química , DNA Antigo/análise , Feminino , Fósseis , Genética Médica , Genética Populacional , Estudo de Associação Genômica Ampla , Humanos , Estilo de Vida , MasculinoRESUMO
The urban peoples of the Swahili coast traded across eastern Africa and the Indian Ocean and were among the first practitioners of Islam among sub-Saharan people1,2. The extent to which these early interactions between Africans and non-Africans were accompanied by genetic exchange remains unknown. Here we report ancient DNA data for 80 individuals from 6 medieval and early modern (AD 1250-1800) coastal towns and an inland town after AD 1650. More than half of the DNA of many of the individuals from coastal towns originates from primarily female ancestors from Africa, with a large proportion-and occasionally more than half-of the DNA coming from Asian ancestors. The Asian ancestry includes components associated with Persia and India, with 80-90% of the Asian DNA originating from Persian men. Peoples of African and Asian origins began to mix by about AD 1000, coinciding with the large-scale adoption of Islam. Before about AD 1500, the Southwest Asian ancestry was mainly Persian-related, consistent with the narrative of the Kilwa Chronicle, the oldest history told by people of the Swahili coast3. After this time, the sources of DNA became increasingly Arabian, consistent with evidence of growing interactions with southern Arabia4. Subsequent interactions with Asian and African people further changed the ancestry of present-day people of the Swahili coast in relation to the medieval individuals whose DNA we sequenced.
Assuntos
População Africana , Asiático , Genética Populacional , Feminino , Humanos , Masculino , População Africana/genética , Asiático/genética , História Medieval , Oceano Índico , Tanzânia , Quênia , Moçambique , Comores , História do Século XV , História do Século XVI , História do Século XVII , Índia/etnologia , Pérsia/etnologia , Arábia/etnologia , DNA Antigo/análiseRESUMO
Multiple lines of genetic and archaeological evidence suggest that there were major demographic changes in the terminal Late Pleistocene epoch and early Holocene epoch of sub-Saharan Africa1-4. Inferences about this period are challenging to make because demographic shifts in the past 5,000 years have obscured the structures of more ancient populations3,5. Here we present genome-wide ancient DNA data for six individuals from eastern and south-central Africa spanning the past approximately 18,000 years (doubling the time depth of sub-Saharan African ancient DNA), increase the data quality for 15 previously published ancient individuals and analyse these alongside data from 13 other published ancient individuals. The ancestry of the individuals in our study area can be modelled as a geographically structured mixture of three highly divergent source populations, probably reflecting Pleistocene interactions around 80-20 thousand years ago, including deeply diverged eastern and southern African lineages, plus a previously unappreciated ubiquitous distribution of ancestry that occurs in highest proportion today in central African rainforest hunter-gatherers. Once established, this structure remained highly stable, with limited long-range gene flow. These results provide a new line of genetic evidence in support of hypotheses that have emerged from archaeological analyses but remain contested, suggesting increasing regionalization at the end of the Pleistocene epoch.
Assuntos
População Negra , DNA Antigo , Genética Populacional , África Subsaariana , Arqueologia , População Negra/genética , População Negra/história , DNA Antigo/análise , Fluxo Gênico/genética , Genoma Humano/genética , História Antiga , HumanosRESUMO
Population history-focused DNA and ancient DNA (aDNA) research in Africa has dramatically increased in the past decade, enabling increasingly fine-scale investigations into the continent's past. However, while international interest in human genomics research in Africa grows, major structural barriers limit the ability of African scholars to lead and engage in such research and impede local communities from partnering with researchers and benefitting from research outcomes. Because conversations about research on African people and their past are often held outside Africa and exclude African voices, an important step for African DNA and aDNA research is moving these conversations to the continent. In May 2023 we held the DNAirobi workshop in Nairobi, Kenya and here we synthesize what emerged most prominently in our discussions. We propose an ideal vision for population history-focused DNA and aDNA research in Africa in ten years' time and acknowledge that to realize this future, we need to chart a path connecting a series of "landmarks" that represent points of consensus in our discussions. These include effective communication across multiple audiences, reframed relationships and capacity building, and action toward structural changes that support science and beyond. We concluded there is no single path to creating an equitable and self-sustaining research ecosystem, but rather many possible routes linking these landmarks. Here we share our diverse perspectives as geneticists, anthropologists, archaeologists, museum curators, and educators to articulate challenges and opportunities for African DNA and aDNA research and share an initial map toward a more inclusive and equitable future.
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DNA Antigo , Genética Populacional , Humanos , DNA Antigo/análise , África , Genômica , População Negra/genéticaRESUMO
The origin and evolution of hominin mortuary practices are topics of intense interest and debate1-3. Human burials dated to the Middle Stone Age (MSA) are exceedingly rare in Africa and unknown in East Africa1-6. Here we describe the partial skeleton of a roughly 2.5- to 3.0-year-old child dating to 78.3 ± 4.1 thousand years ago, which was recovered in the MSA layers of Panga ya Saidi (PYS), a cave site in the tropical upland coast of Kenya7,8. Recent excavations have revealed a pit feature containing a child in a flexed position. Geochemical, granulometric and micromorphological analyses of the burial pit content and encasing archaeological layers indicate that the pit was deliberately excavated. Taphonomical evidence, such as the strict articulation or good anatomical association of the skeletal elements and histological evidence of putrefaction, support the in-place decomposition of the fresh body. The presence of little or no displacement of the unstable joints during decomposition points to an interment in a filled space (grave earth), making the PYS finding the oldest known human burial in Africa. The morphological assessment of the partial skeleton is consistent with its assignment to Homo sapiens, although the preservation of some primitive features in the dentition supports increasing evidence for non-gradual assembly of modern traits during the emergence of our species. The PYS burial sheds light on how MSA populations interacted with the dead.
Assuntos
Sepultamento/história , Fósseis , Esqueleto/anatomia & histologia , Animais , Osso e Ossos/anatomia & histologia , Pré-Escolar , Evolução Cultural/história , Dentição , História Antiga , Hominidae/anatomia & histologia , Hominidae/classificação , Humanos , QuêniaRESUMO
We are a group of archaeologists, anthropologists, curators and geneticists representing diverse global communities and 31 countries. All of us met in a virtual workshop dedicated to ethics in ancient DNA research held in November 2020. There was widespread agreement that globally applicable ethical guidelines are needed, but that recent recommendations grounded in discussion about research on human remains from North America are not always generalizable worldwide. Here we propose the following globally applicable guidelines, taking into consideration diverse contexts. These hold that: (1) researchers must ensure that all regulations were followed in the places where they work and from which the human remains derived; (2) researchers must prepare a detailed plan prior to beginning any study; (3) researchers must minimize damage to human remains; (4) researchers must ensure that data are made available following publication to allow critical re-examination of scientific findings; and (5) researchers must engage with other stakeholders from the beginning of a study and ensure respect and sensitivity to stakeholder perspectives. We commit to adhering to these guidelines and expect they will promote a high ethical standard in DNA research on human remains going forward.
Assuntos
Cadáver , DNA Antigo/análise , Guias como Assunto , Genética Humana/ética , Internacionalidade , Biologia Molecular/ética , Indígena Americano ou Nativo do Alasca , Antropologia/ética , Arqueologia/ética , Relações Comunidade-Instituição , Humanos , Povos Indígenas , Participação dos Interessados , TraduçõesRESUMO
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.
Assuntos
População Negra/genética , População Negra/história , Comportamento Alimentar/etnologia , Migração Humana/história , Filogenia , Alelos , Animais , Arqueologia , Sepultamento , Camarões , Criança , Pré-Escolar , Cromossomos Humanos Y/genética , DNA Antigo/análise , Feminino , Marcadores Genéticos/genética , Genética Populacional , Genoma Humano/genética , Haplótipos/genética , História Antiga , Humanos , Idioma/história , Masculino , Pan troglodytes/genética , Análise de Componente PrincipalRESUMO
The development of pastoralism transformed human diets and societies in grasslands worldwide. The long-term success of cattle herding in Africa has been sustained by dynamic food systems, consumption of a broad range of primary and secondary livestock products, and the evolution of lactase persistence (LP), which allows digestion of lactose into adulthood and enables the milk-based, high-protein, low-calorie diets characteristic of contemporary pastoralists. Despite the presence of multiple alleles associated with LP in ancient and present-day eastern African populations, the contexts for selection for LP and the long-term development of pastoralist foodways in this region remain unclear. Pastoral Neolithic (c 5000 to 1200 BP) faunas indicate that herders relied on cattle, sheep, and goats and some hunting, but direct information on milk consumption, plant use, and broader culinary patterns is rare. Combined chemical and isotopic analysis of ceramic sherds (n = 125) from Pastoral Neolithic archaeological contexts in Kenya and Tanzania, using compound-specific δ13C and Δ13C values of the major fatty acids, provides chemical evidence for milk, meat, and plant processing by ancient herding societies in eastern Africa. These data provide the earliest direct evidence for milk product consumption and reveal a history of reliance on animal products and other nutrients, likely extracted through soups or stews, and plant foods. They document a 5,000-y temporal framework for eastern Africa pastoralist cuisines and cultural contexts for selection for alleles distinctive of LP in eastern Africa.
Assuntos
Arqueologia , Dieta , Análise de Alimentos/história , Leite/química , Animais , Isótopos de Carbono/química , Bovinos , Cerâmica/história , Dieta/história , Ácidos Graxos/química , Ácidos Graxos/isolamento & purificação , Cabras , História Antiga , Migração Humana/história , Humanos , Lactase/química , Lactose/química , Gado , Carne/análise , OvinosRESUMO
The Middle to Later Stone Age transition is a critical period of human behavioral change that has been variously argued to pertain to the emergence of modern cognition, substantial population growth, and major dispersals of Homo sapiens within and beyond Africa. However, there is little consensus about when the transition occurred, the geographic patterning of its emergence, or even how it is manifested in the stone tool technology that is used to define it. Here, we examine a long sequence of lithic technological change at the cave site of Panga ya Saidi, Kenya, that spans the Middle and Later Stone Age and includes human occupations in each of the last five Marine Isotope Stages. In addition to the stone artifact technology, Panga ya Saidi preserves osseous and shell artifacts, enabling broader considerations of the covariation between different spheres of material culture. Several environmental proxies contextualize the artifactual record of human behavior at Panga ya Saidi. We compare technological change between the Middle and Later Stone Age with on-site paleoenvironmental manifestations of wider climatic fluctuations in the Late Pleistocene. The principal distinguishing feature of Middle from Later Stone Age technology at Panga ya Saidi is the preference for fine-grained stone, coupled with the creation of small flakes (miniaturization). Our review of the Middle to Later Stone Age transition elsewhere in eastern Africa and across the continent suggests that this broader distinction between the two periods is in fact widespread. We suggest that the Later Stone Age represents new short use-life and multicomponent ways of using stone tools, in which edge sharpness was prioritized over durability.
Assuntos
Arqueologia , Florestas , Tecnologia/história , Clima Tropical , História Antiga , Humanos , QuêniaRESUMO
Limited data are available for outcomes of simultaneous liver-kidney (SLK) transplantation using donation after cardiac death (DCD) donors. The outcomes of 12 DCD-SLK transplants and 54 SLK transplants using donation after brain death (DBD) donors were retrospectively compared. The baseline demographics were similar for the DCD-SLK and DBD-SLK groups except for the higher liver donor risk index for the DCD-SLK group (1.8 ± 0.4 versus 1.3 ± 0.4, P = 0.001). The rates of surgical complications and graft rejections within 1 year were comparable for the DCD-SLK and DBD-SLK groups. Delayed renal graft function was twice as common in the DCD-SLK group. At 1 year, the serum creatinine levels and the iothalamate glomerular filtration rates were similar for the groups. The patient, liver graft, and kidney graft survival rates at 1 year were comparable for the groups (83.3%, 75.0%, and 82.5% for the DCD-SLK group and 92.4%, 92.4%, and 92.6% for the DBD-SLK group, P = 0.3 for all). The DCD-SLK group had worse patient, liver graft, and kidney graft survival at 3 years (62.5%, 62.5%, and 58.9% versus 90.5%, 90.5%, and 90.6%, P = 0.03 for all) and at 5 years (62.5%, 62.5%, and 58.9% versus 87.4%, 87.4%, and 87.7%, P < 0.05 for all). An analysis of the Organ Procurement and Transplantation Network database showed inferior 1- and 5-year patient and graft survival rates for DCD-SLK patients versus DBD-SLK patients. In conclusion, despite comparable rates of surgical and medical complications and comparable kidney function at 1 year, DCD-SLK transplantation was associated with inferior long-term survival in comparison with DBD-SLK transplantation.
Assuntos
Morte Encefálica , Cardiopatias/mortalidade , Transplante de Rim , Transplante de Fígado , Doadores de Tecidos , Obtenção de Tecidos e Órgãos , Adulto , Idoso , Bases de Dados Factuais , Função Retardada do Enxerto/etiologia , Feminino , Florida , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Humanos , Transplante de Rim/efeitos adversos , Transplante de Rim/mortalidade , Transplante de Fígado/efeitos adversos , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Broad-based formal quality improvement curriculum emphasizing Six Sigma and the DMAIC approach developed by our institution is required for physicians in training. DMAIC methods evaluated the common outcome of postoperative hyponatremia, thus resulting in collaboration to prevent hyponatremia in the renal transplant population. METHODS: To define postoperative hyponatremia in renal transplant recipients, a project charter outlined project aims. To measure postoperative hyponatremia, serum sodium at admission and immediately postoperative were recorded by retrospective review of renal transplant recipient charts from June 29, 2010 to December 31, 2011. An Ishikawa diagram was generated to analyze potential causative factors. Interdisciplinary collaboration and hospital policy assessment determined necessary improvements to prevent hyponatremia. Continuous monitoring in control phase was performed by establishing the goal of <10% of transplant recipients with abnormal serum sodium annually through quarterly reduction of hyponatremia by 30% to reach this goal. RESULTS: Of 54 transplant recipients, postoperative hyponatremia occurred in 92.6% of patients. These potential causes were evaluated: 1) Hemodialysis was more common than peritoneal dialysis. 2) Alemtuzumab induction was more common than antithymocyte globulin. 3) A primary diagnosis of diabetes existed in 16 patients (30%). 4) Strikingly, 51 patients received 0.45% sodium chloride intraoperatively, suggesting this as the most likely cause of postoperative hyponatremia. A hospital policy change to administer 0.9% sodium chloride during renal transplantation resulted in normal serum sodium levels postoperatively in 59 of 64 patients (92.2%). CONCLUSION: The DMAIC approach and formal quality curriculum for trainees addresses core competencies by providing a framework for problem solving, interdisciplinary collaboration, and process improvement.
Assuntos
Hiponatremia/prevenção & controle , Transplante de Rim , Complicações Pós-Operatórias/prevenção & controle , Melhoria de Qualidade , Educação Baseada em Competências , Humanos , Hiponatremia/epidemiologia , Incidência , Comunicação Interdisciplinar , Complicações Pós-Operatórias/epidemiologia , Aprendizagem Baseada em Problemas , Estudos Retrospectivos , Estados Unidos/epidemiologiaRESUMO
The success of renal, liver, cardiac, pulmonary, and other solid organ transplantation (SOT) has resulted in increasing volume of transplant procedures and recipient survivorship. Subsequently, many SOT patients develop end-stage degenerative joint disease and are presenting for total hip or total knee arthroplasty more frequently. Surgeons must be aware of the medical complexities and prepare for the perioperative risks associated with these immunocompromised patients. Preoperative evaluation should be conducted in coordination with transplant specialists to ensure optimization, including appropriate surgical timing and advanced, organ-specific medical assessments. Although often unable to be modified, the transplant patient's antirejection medication regimens should be reviewed with understanding of inherent risks of poor wound healing or acute infection. Despite higher rates of complications, revision surgeries, and mortality compared with the general population, SOT recipients continue to demonstrate markedly improved pain relief, function, and quality of life. An ongoing multidisciplinary approach is required throughout the perioperative process and beyond to deliver successful outcomes after total joint arthroplasty in the SOT population.
Assuntos
Artroplastia do Joelho , Transplante de Órgãos , Humanos , Qualidade de VidaRESUMO
Bone surface modifications (BSMs) in faunal assemblages are frequently used to infer past agency and actions of hominins and carnivores, with implications for the emergence of key human behaviours. Patterning of BSMs has mostly been defined as a combination of the intensity of marks per bone portion and sometimes per element. Numerous variables involved in butchery can condition cut mark anatomical distribution, so much so that these variables are widely assumed to be stochastic. Here, we present a new methodological approach using a novel geospatial tool (Ikhnos) which combines the three-dimensional spatial documentation of cut mark patterns with spatial statistics based on wavelets, applied to three experimental and ethnoarchaeological faunal assemblages. We use wavelets to identify patterning of multiple longitudinal series of cut mark distributions on bones, and to establish similarities or differences in patterning within and across different assemblages. This method demonstrates the existence of general and behaviour-specific butchery patterns. It can also be used to effectively assess the proportion of mark clustering that is due to randomness, versus that which is conditioned by the butchery process.
Assuntos
Fósseis , Hominidae , Animais , Osso e Ossos , HumanosRESUMO
The human colonization of eastern Africa's near- and offshore islands was accompanied by the translocation of several domestic, wild and commensal fauna, many of which had long-term impacts on local environments. To better understand the timing and nature of the introduction of domesticated caprines (sheep and goat) to these islands, this study applied collagen peptide fingerprinting (Zooarchaeology by Mass Spectrometry or ZooMS) to archaeological remains from eight Iron Age sites, dating between ca 300 and 1000 CE, in the Zanzibar, Mafia and Comoros archipelagos. Where previous zooarchaeological analyses had identified caprine remains at four of these sites, this study identified goat at seven sites and sheep at three, demonstrating that caprines were more widespread than previously known. The ZooMS results support an introduction of goats to island eastern Africa from at least the seventh century CE, while sheep in our sample arrived one-two centuries later. Goats may have been preferred because, as browsers, they were better adapted to the islands' environments. The results allow for a more accurate understanding of early caprine husbandry in the study region and provide a critical archaeological baseline for examining the potential long-term impacts of translocated fauna on island ecologies.
RESUMO
How food production first entered eastern Africa ~5000 years ago and the extent to which people moved with livestock is unclear. We present genome-wide data from 41 individuals associated with Later Stone Age, Pastoral Neolithic (PN), and Iron Age contexts in what are now Kenya and Tanzania to examine the genetic impacts of the spreads of herding and farming. Our results support a multiphase model in which admixture between northeastern African-related peoples and eastern African foragers formed multiple pastoralist groups, including a genetically homogeneous PN cluster. Additional admixture with northeastern and western African-related groups occurred by the Iron Age. These findings support several movements of food producers while rejecting models of minimal admixture with foragers and of genetic differentiation between makers of distinct PN artifacts.
Assuntos
Agricultura/história , Genoma Humano , Migração Humana/história , Ocupações/história , DNA Antigo , História Antiga , Humanos , Quênia , TanzâniaRESUMO
The Middle to Later Stone Age transition in Africa has been debated as a significant shift in human technological, cultural, and cognitive evolution. However, the majority of research on this transition is currently focused on southern Africa due to a lack of long-term, stratified sites across much of the African continent. Here, we report a 78,000-year-long archeological record from Panga ya Saidi, a cave in the humid coastal forest of Kenya. Following a shift in toolkits ~67,000 years ago, novel symbolic and technological behaviors assemble in a non-unilinear manner. Against a backdrop of a persistent tropical forest-grassland ecotone, localized innovations better characterize the Late Pleistocene of this part of East Africa than alternative emphases on dramatic revolutions or migrations.
RESUMO
The originally published version of this Article contained an error in Fig. 3, whereby an additional unrelated graph was overlaid on top of the magnetic susceptibility plot. Furthermore, the Article title contained an error in the capitalisation of 'Stone Age'. Both of these errors have now been corrected in both the PDF and HTML versions of the Article.
RESUMO
Atopic dermatitis (AD) increases health care utilization, affects patient quality of life, places a burden on caregivers, decreases patient/parent productivity, and adds to health care costs. Few studies have examined the effect of specific treatment modalities across a variety of AD-related outcomes. This prospective, multicenter, open-label longitudinal study of adult and pediatric patients with moderate to severe AD was conducted to evaluate the effect of a specific therapeutic intervention on AD-related outcomes over a period of 6 months. Surveys collected physician clinical assessments and patient- and caregiver-reported data across the following domains: clinical outcome, health care utilization/costs, quality of life, physical appearance, productivity/absenteeism, and medication compliance. This study is intended to help guide future research efforts on the net costs and benefits of different interventions across a diverse set of domains and in larger populations.
Assuntos
Dermatite Atópica/tratamento farmacológico , Dermatite Atópica/economia , Qualidade de Vida , Administração Tópica , Adolescente , Criança , Pré-Escolar , Efeitos Psicossociais da Doença , Dermatite Atópica/patologia , Feminino , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/economia , Imunossupressores/uso terapêutico , Masculino , Medicamentos sem Prescrição/economia , Medicamentos sem Prescrição/uso terapêutico , Pomadas , Cooperação do Paciente/estatística & dados numéricos , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Estudos Prospectivos , Índice de Gravidade de Doença , Inquéritos e Questionários , Tacrolimo/administração & dosagem , Tacrolimo/economia , Tacrolimo/uso terapêutico , Fatores de Tempo , Resultado do TratamentoRESUMO
Human-mediated biological exchange has had global social and ecological impacts. In sub-Saharan Africa, several domestic and commensal animals were introduced from Asia in the pre-modern period; however, the timing and nature of these introductions remain contentious. One model supports introduction to the eastern African coast after the mid-first millennium CE, while another posits introduction dating back to 3000 BCE. These distinct scenarios have implications for understanding the emergence of long-distance maritime connectivity, and the ecological and economic impacts of introduced species. Resolution of this longstanding debate requires new efforts, given the lack of well-dated fauna from high-precision excavations, and ambiguous osteomorphological identifications. We analysed faunal remains from 22 eastern African sites spanning a wide geographic and chronological range, and applied biomolecular techniques to confirm identifications of two Asian taxa: domestic chicken (Gallus gallus) and black rat (Rattus rattus). Our approach included ancient DNA (aDNA) analysis aided by BLAST-based bioinformatics, Zooarchaeology by Mass Spectrometry (ZooMS) collagen fingerprinting, and direct AMS (accelerator mass spectrometry) radiocarbon dating. Our results support a late, mid-first millennium CE introduction of these species. We discuss the implications of our findings for models of biological exchange, and emphasize the applicability of our approach to tropical areas with poor bone preservation.
Assuntos
Espécies Introduzidas/história , África , Animais , Animais Domésticos/genética , Arqueologia , Ásia , Galinhas , Colágeno/análise , Colágeno/genética , Impressões Digitais de DNA , História Antiga , Datação Radiométrica , RatosRESUMO
With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja) off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM), one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age). This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for human and animal communities.