scholarly journals Recurrent Collection of Drosophila melanogaster from Wild African Environments and Genomic Insights into Species History

2019 ◽  
Vol 37 (3) ◽  
pp. 627-638 ◽  
Author(s):  
Quentin D Sprengelmeyer ◽  
Suzan Mansourian ◽  
Jeremy D Lange ◽  
Daniel R Matute ◽  
Brandon S Cooper ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Demographic History ◽  
Central Africa ◽  
Model Organism ◽  
Sub Saharan Africa ◽  
Wilderness Areas ◽  
Southern Central ◽  
History Of ◽  
Sub Saharan ◽  
Improved Model

Abstract A long-standing enigma concerns the geographic and ecological origins of the intensively studied vinegar fly, Drosophila melanogaster. This globally distributed human commensal is thought to originate from sub-Saharan Africa, yet until recently, it had never been reported from undisturbed wilderness environments that could reflect its precommensal niche. Here, we document the collection of 288 D. melanogaster individuals from multiple African wilderness areas in Zambia, Zimbabwe, and Namibia. The presence of D. melanogaster in these remote woodland environments is consistent with an ancestral range in southern-central Africa, as opposed to equatorial regions. After sequencing the genomes of 17 wilderness-collected flies collected from Kafue National Park in Zambia, we found reduced genetic diversity relative to town populations, elevated chromosomal inversion frequencies, and strong differences at specific genes including known insecticide targets. Combining these genomes with existing data, we probed the history of this species’ geographic expansion. Demographic estimates indicated that expansion from southern-central Africa began ∼13,000 years ago, with a Saharan crossing soon after, but expansion from the Middle East into Europe did not begin until roughly 1,800 years ago. This improved model of demographic history will provide an important resource for future evolutionary and genomic studies of this key model organism. Our findings add context to the history of D. melanogaster, while opening the door for future studies on the biological basis of adaptation to human environments.

scholarly journals Discovery of Drosophila melanogaster from Wild African Environments and Genomic Insights into Species History

2018 ◽  
Author(s):  
Quentin D. Sprengelmeyer ◽  
Suzan Mansourian ◽  
Jeremy D. Lange ◽  
Daniel R. Matute ◽  
Brandon S. Cooper ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Demographic History ◽  
Historical Context ◽  
Model Organism ◽  
Widespread Species ◽  
Wilderness Areas ◽  
Genomic Studies ◽  
History Of ◽  
Sub Saharan ◽  
Improved Model

A long-standing enigma concerns the geographic and ecological origins of the intensively studied vinegar fly, Drosophila melanogaster, a globally widespread species [1] which “has invariably appeared to be a strict human commensal” [2]. In spite of its sub-Saharan origins, this species has never been reported from undisturbed wilderness environments that might reflect its pre-commensal niche [3]. Here, we document the collection of 288 D. melanogaster individuals from African wilderness areas in Zambia, Zimbabwe, and Namibia. After sequencing the genomes of 17 flies collected from Kafue National Park, Zambia, we found reduced genetic diversity relative to town populations, elevated chromosomal inversion frequencies, and strong differences at specific genes including known insecticide targets. Combining these new genomes with prior data enabled us to gain novel insights into the history of this species’ geographic expansion. Our demographic estimates indicated that an expansion from southern Africa began approximately 10,000 years ago, with a Saharan crossing soon after, but expansion from the Middle East into Europe did not begin until roughly 1,400 years ago. This improved model of demographic history will provide a critical resource for future evolutionary and genomic studies of this key model organism. Our results add historical context to the species’ human association, and the opportunity to study wilderness populations opens the door for future studies on the biological basis of its adaptation to human environments.

Women in Gabon

2021 ◽  
Author(s):  
Claire H. Griffiths
Keyword(s):  
Central Africa ◽  
Early Period ◽  
Sub Saharan Africa ◽  
African Women ◽  
Female Population ◽  
History Of ◽  
Sub Saharan ◽  
Tropical Woods ◽  
New Research ◽  
Export Revenue

Gabon, a small oil-rich country straddling the equator on the west coast of Africa, is the wealthiest of France’s former colonies. An early period of colonization in the 19th century resulted in disease, famine, and economic failure. The creation of French Equatorial Africa in 1910 marked the beginning of the sustained lucrative exploitation of Gabon’s natural resources. Gabon began off-shore oil production while still a colony of France. Uranium was also discovered in the last decade of the French Equatorial African empire. Coupled with rich reserves in tropical woods, Gabon has achieved, since independence in 1960, a higher level of export revenue per capita of population than any other country in sub-Saharan Africa in the postcolonial era. However, significant inequality has characterized access to wealth through paid employment throughout the recorded history of monetized labor. While fortunes have been amassed by a minute proportion of the female population of Gabon associated with the ruling regime, and a professional female middle-class has emerged, inequalities of opportunity and reward continue to mark women’s experience of life in this little-known country of West Central Africa. The key challenge facing scholars researching the history of women in Gabon remains the relative lack of historical resources. While significant strides have been made over the past decade, research on women’s history in Francophone Africa published in English or French remains embryonic. French research on African women began to make a mark in the last decade of colonization, notably with the work of Denise Paulme, but then remained a neglected area for decades. The publication in 1994 of Les Africaines by French historian Catherine Coquery-Vidrovitch was hailed at the time as a pioneering work in French historiography. But even this new research contained no analysis of and only a passing reference to women in Gabon.

scholarly journals The demographic history of African Drosophila melanogaster

2018 ◽  
Author(s):  
Adamandia Kapopoulou ◽  
Susanne P. Pfeifer ◽  
Jeffrey D. Jensen ◽  
Stefan Laurent
Keyword(s):  
Drosophila Melanogaster ◽  
Demographic History ◽  
Research Question ◽  
Model Organism ◽  
Quantitative Model ◽  
Population History ◽  
Parameter Estimates ◽  
Demographic Model ◽  
African Populations ◽  
History Of

ABSTRACTAs one of the most commonly utilized organisms in the study of local adaptation, an accurate characterization of the demographic history of Drosophila melanogaster remains as an important research question. This owes both to the inherent interest in characterizing the population history of this model organism, as well as to the well-established importance of an accurate null demographic model for increasing power and decreasing false positive rates in genomic scans for positive selection. While considerable attention has been afforded to this issue in non-African populations, less is known about the demographic history of African populations, including from the ancestral range of the species. While qualitative predictions and hypotheses have previously been forwarded, we here present a quantitative model fitting of the population history characterizing both the ancestral Zambian population range as well as the subsequently colonized west African populations, which themselves served as the source of multiple non-African colonization events. These parameter estimates thus represent an important null model for future investigations in to African and non-African D. melanogaster populations alike.

scholarly journals The recent colonization history of the most widespread Podocarpus tree species in Afromontane forests

2020 ◽  
Vol 126 (1) ◽  
pp. 73-83
Author(s):  
Jérémy Migliore ◽  
Anne-Marie Lézine ◽  
Olivier J Hardy
Keyword(s):  
Dna Sequences ◽  
Demographic History ◽  
Central Africa ◽  
Single Species ◽  
High Elevation ◽  
Nuclear Ribosomal Dna ◽  
Afromontane Forests ◽  
Wide Range ◽  
History Of ◽  
Sub Saharan

Abstract Background and Aims Afromontane forests host a unique biodiversity distributed in isolated high-elevation habitats within a matrix of rain forests or savannahs, yet they share a remarkable flora that raises questions about past connectivity between currently isolated forests. Here, we focused on the Podocarpus latifolius–P. milanjianus complex (Podocarpaceae), the most widely distributed conifers throughout sub-Saharan African highlands, to infer its demographic history from genetic data. Methods We sequenced the whole plastid genome, mitochondrial DNA regions and nuclear ribosomal DNA of 88 samples from Cameroon to Angola in western Central Africa and from Kenya to the Cape region in eastern and southern Africa to reconstruct time-calibrated phylogenies and perform demographic inferences. Key Results We show that P. latifolius and P. milanjianus form a single species, whose lineages diverged during the Pleistocene, mostly between approx, 200 000 and 300 000 years BP, after which they underwent a wide range expansion leading to their current distributions. Confronting phylogenomic and palaeoecological data, we argue that the species originated in East Africa and reached the highlands of the Atlantic side of Africa through two probable latitudinal migration corridors: a northern one towards the Cameroon volcanic line, and a southern one towards Angola. Although the species is now rare in large parts of its range, no demographic decline was detected, probably because it occurred too recently to have left a genetic signature in our DNA sequences. Conclusions Despite the ancient and highly fluctuating history of podocarps in Africa revealed by palaeobotanical records, the extended distribution of current P. latifolius/milanjianus lineages is shown to result from a more recent history, mostly during the mid-late Pleistocene, when Afromontane forests were once far more widespread and continuous.

Christianity in the Twentieth Century

2019 ◽  
Author(s):  
Brian Stanley
Keyword(s):  
Latin America ◽  
Racial Identity ◽  
Sub Saharan Africa ◽  
Central Importance ◽  
Regional Survey ◽  
History Of Christianity ◽  
The World ◽  
History Of ◽  
Sub Saharan ◽  
Different Parts

This book charts the transformation of one of the world's great religions during an age marked by world wars, genocide, nationalism, decolonization, and powerful ideological currents, many of them hostile to Christianity. The book traces how Christianity evolved from a religion defined by the culture and politics of Europe to the expanding polycentric and multicultural faith it is today—one whose growing popular support is strongest in sub-Saharan Africa, Latin America, China, and other parts of Asia. The book sheds critical light on themes of central importance for understanding the global contours of modern Christianity, illustrating each one with contrasting case studies, usually taken from different parts of the world. Unlike other books on world Christianity, this one is not a regional survey or chronological narrative, nor does it focus on theology or ecclesiastical institutions. The book provides a history of Christianity as a popular faith experienced and lived by its adherents, telling a compelling and multifaceted story of Christendom's fortunes in Europe, North America, and across the rest of the globe. It demonstrates how Christianity has had less to fear from the onslaughts of secularism than from the readiness of Christians themselves to accommodate their faith to ideologies that privilege racial identity or radical individualism.

scholarly journals Corrigendum to: Demographic history of the human commensal Drosophila melanogaster

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
J Roman Arguello ◽  
Stefan Laurent ◽  
Andrew G Clark
Keyword(s):  
Drosophila Melanogaster ◽  
Demographic History ◽  
History Of

Forced Labour in the “Gorgulho Years”: Understanding Reform and Repression in Rural São Tomé e Príncipe, 1945–1953

Itinerario ◽  
2014 ◽  
Vol 38 (1) ◽  
pp. 103-124 ◽  
Author(s):  
Alexander Keese
Keyword(s):  
Economic Change ◽  
Social Conditions ◽  
Sub Saharan Africa ◽  
History Of ◽  
Colonial Policies ◽  
Sub Saharan ◽  
Incomplete Images ◽  
Forced Labour ◽  
Sao Tome E Principe

The crossroads of nationalist historiographies in sub-Saharan Africa and of the history of developmentalist attempts that characterise the European late colonial states, have left us with very incomplete images of important trajectories. In the seemingly more “liberal” large colonial empires—notably the French and British—sails were set by 1945 towards a policy of investment and economic change. Some of the scholarly debates question whether this investment was genuine or just a last resort to avoid (rapid) decolonisation; others put the emphasis on inadequate routines of development implemented in these territories, many of which have apparently been continued since decolonisation.In this context, we encounter a clear lack of understanding about how decisions made by individual actors on the administrative level interacted with the larger panorama of social conditions in colonial territories, and of the consequences that these interactions had for the paths towards decolonisation. For a smaller empire such as the Belgian colony of Congo-Léopoldville, these processes are still more obscure; and for the colonies ruled by authoritarian metropoles, as in the cases of territories under Spanish and Portuguese rule, stagnation and absence of change are often taken for granted. In other words, these territories, which were under the rule of metropoles regarded as rather weak in economic terms, are treated as unrepresentative of the broader, European movement towards change in colonial policies. However, the conditions of change towards economic and social modernisation in this latter group of empires, even when inhibited by lack of funding and weak professionalisation of the administration, are frequently very telling for the broader range of challenges that the late colonial states faced.

scholarly journals First Report of East African Cassava Mosaic Begomovirus in Nigeria

Plant Disease ◽  
1999 ◽  
Vol 83 (4) ◽  
pp. 398-398 ◽  
Author(s):  
F. O. Ogbe ◽  
G. I. Atiri ◽  
D. Robinson ◽  
S. Winter ◽  
A. G. O. Dixon ◽  
...  
Keyword(s):  
Central Africa ◽  
Mosaic Disease ◽  
Sub Saharan Africa ◽  
Cassava Mosaic Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
East African ◽  
African Countries ◽  
Manihot Esculenta Crantz ◽  
Cross River State ◽  
Sub Saharan

Cassava (Manihot esculenta Crantz) is an important food crop in sub-Saharan Africa. One of the major production constraints is cassava mosaic disease caused by African cassava mosaic (ACMV) and East African cassava mosaic (EACMV) begomoviruses. ACMV is widespread in its distribution, occurring throughout West and Central Africa and in some eastern and southern African countries. In contrast, EACMV has been reported to occur mainly in more easterly areas, particularly in coastal Kenya and Tanzania, Malawi, and Madagascar. In 1997, a survey was conducted in Nigeria to determine the distribution of ACMV and its strains. Samples from 225 cassava plants showing mosaic symptoms were tested with ACMV monoclonal antibodies (MAbs) in triple antibody sandwich enzyme-linked immunosorbent assay (1). Three samples reacted strongly with MAbs that could detect both ACMV and EACMV. One of them did not react with ACMV-specific MAbs while the other two reacted weakly with such MAbs. With polymerase chain reaction (2), the presence of EACMV and a mixture of EACMV and ACMV in the respective samples was confirmed. These samples were collected from two villages: Ogbena in Kwara State and Akamkpa in Cross River State. Co-infection of some cassava varieties with ACMV and EACMV leads to severe symptoms. More importantly, a strain of mosaic geminivirus known as Uganda variant arose from recombination between the two viruses (2). This report provides evidence for the presence of EACMV in West Africa. References: (1) J. E. Thomas et al. J. Gen. Virol. 67:2739, 1986. (2) X. Zhou et al. J. Gen. Virol. 78:2101, 1997.

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