scholarly journals Phylogeographic analysis reveals an ancient East African origin of the human herpes simplexvirus 2 dispersal out-of-Africa.

2022 ◽  
Author(s):  
Jennifer L. Havens ◽  
Sebastien Calvignac-Spencer ◽  
Kevin Merkel ◽  
Sonia Burrel ◽  
David Boutolleau ◽  
...  
Keyword(s):  
East Africa ◽  
Molecular Clock ◽  
Central Africa ◽  
Human Migration ◽  
Evolutionary Rates ◽  
Human Herpes ◽  
Phylogeographic Analysis ◽  
West And Central Africa ◽  
Out Of Africa ◽  
Competing Hypotheses

Human herpes simplex virus 2 (HSV-2) is a globally ubiquitous, slow evolving DNA virus. HSV-2 genomic diversity can be divided into two main groups: an African lineage and worldwide lineage. Competing hypotheses have been put forth to explain the history of HSV-2. HSV-2 may have originated in Africa and then followed the first wave of human migration out of Africa between 50-100 kya. Alternatively, HSV-2 may have migrated out of Africa via the trans-Atlantic slave trade within the last 150-500 years. The lack of HSV-2 genomes from West and Central Africa, combined with a lack of molecular clock signal in HSV-2 has precluded robust testing of these competing hypotheses. Here, we expand the geographic sampling of HSV-2 genomes in order to resolve the geography and timing of divergence events within HSV-2. We analyze 65 newly sequenced HSV-2 genomes collected from primarily West and Central Africa along with 330 previously published genomes sampled over a 47-year period. Evolutionary simulations confirm that the molecular clock in HSV-2 is too slow to be detected using available data. However, phylogeographic analysis indicates that all biologically plausible evolutionary rates would place the ancestor of the worldwide lineage in East Africa, arguing against the trans-Atlantic slave trade as the source of worldwide diversity. The best supported evolutionary rates between 4.2x10-8 and 5.6x10-8 substitutions/site/year suggest a most recent common ancestor for HSV-2 around 90-120 kya and initial dispersal around 21.9-29.3 kya. These dates suggest HSV-2 left Africa during subsequent waves of human migration out of East Africa.

scholarly journals Human origin and migration deciphered from a novel genomic footprints of mitochondrial sequences

2019 ◽  
Author(s):  
Aritra Mahapatra ◽  
Jayanta Mukherjee
Keyword(s):  
Phylogenetic Trees ◽  
Central Africa ◽  
Molecular Data ◽  
Modern Human ◽  
Human Migration ◽  
Genomic Feature ◽  
Genomic Studies ◽  
West And Central Africa ◽  
High Bootstrap ◽  
And Migration

AbstractThe origin of modern human and their migration across the world is one of the most debated topics for the decades. There exist two different hypotheses, recent African origin and multi-regional evolution, based on the genomic studies, haplogroups, archaeological records, cultural behaviors, palaeontology studies, etc. Various studies placed the modern humans in a phylogenetic tree to depict the relationships among them. The debate for determining those regions of Africa which witnessed the first origin of humans still exists. The conflicts between the results obtained from the molecular data and the archaeological and palaeontological reports still exist. We adopt a novel genomic feature derived from the whole mitochondrial sequence, and using a novel distance function the phylogenetic trees are constructed based on the feature which provide a new insight on human migration. We propose a new method to derive the bootstrap replica from the genome sequences by considering the genetic variance to demonstrate the robustness of the obtained trees. The results derived from the genomic feature are more consistent with the archaeological findings based on the time of origin of different communities. We find that west and central African communities are placed at the basal point with a very high bootstrap score. This study roughly estimates the existence of the archaic human at 800-900 kilo years ago and presence of human in Africa at 600-700 kilo years ago. This supports the presence of an ancestor in the west and central Africa much earlier than that of the fossils identified.

scholarly journals A new species of Asphinctopone (Hymenoptera: Formicidae: Ponerinae) from Tanzania

Zootaxa ◽  
2010 ◽  
Vol 2480 (1) ◽  
pp. 27 ◽  
Author(s):  
PETER G. HAWKES
Keyword(s):  
New Species ◽  
East Africa ◽  
Related Species ◽  
Central Africa ◽  
First Record ◽  
Potential Range ◽  
Closely Related Species ◽  
Ponerine Ants ◽  
West And Central Africa ◽  
A New Species

Asphinctopone is a rarely encountered genus of ponerine ants, previously known only from the wet forest zones of West and central Africa. In the most recent revision of the genus Bolton & Fisher synonymised the three previously described species under A. sylvestrii Santschi and described one new but very closely related species, A. differens Bolton & Fisher. A very distinctive new species, Asphinctopone pilosa sp. n., is described from Tanzania and represents the first record of this genus from East Africa. Modifications to the diagnosis of the genus and an updated key to the species of Asphinctopone are presented. An analysis of the distribution records of Asphinctopone, using BIOCLIM and DOMAIN as implemented in DIVA-GIS 7.1 to provide preliminary predictions of the potential range of the genus, is also provided.

Regional delegations in Africa — Mozambique — Mission of delegate-general for Latin America — Chile — Asian sub-continent — People's Republic of China — Middle East

1974 ◽  
Vol 14 (156) ◽  
pp. 130-134
Keyword(s):  
Latin America ◽  
Middle East ◽  
East Africa ◽  
Addis Ababa ◽  
Central Africa ◽  
The Other ◽  
Red Cross ◽  
Republic Of China ◽  
Full Support ◽  
West And Central Africa

In 1970, the ICRC opened two regional delegations in Africa, one at Yaoundé (Cameroon) for West and Central Africa, and the other at Addis Ababa (Ethiopia) for East Africa. In both countries, the ICRC permanent delegates enjoyed throughout their mission the full support of the authorities and the co-operation of their National Red Cross Societies.

Soils of the lowland forests of West and Central Africa

1996 ◽  
Vol 104 ◽  
pp. 15-29 ◽  
Author(s):  
A. S. R. Juo ◽  
L. P. Wilding
Keyword(s):  
East Africa ◽  
Central Africa ◽  
Congo Basin ◽  
The West ◽  
Forest Zone ◽  
Lower Elevation ◽  
Lowland Forests ◽  
West And Central Africa ◽  
Hydrological Cycles ◽  
Great Rift Valley

The forest zone of West and Central Africa comprises the coastal and adjacent inland regions bounded the semi-deciduous forests in the west and the equatorial forests in central Africa and the Congo basin. Sedimentary plains, developed mostly on weathered sandy materials, lie along the coastal stretches and cover vast areas of the Congo basin. Behind the coast the plain rises gradually to hills and plateaus of much lower elevation than those of the highlands of East Africa. Two great rivers, the Niger and the Congo, which discharge huge volumes of fresh water to the Atlantic Ocean, are major contributors to the hydrological cycles of the rain forests ecosystems of the Guinea–Congo Region. The Niger originates from the forested highlands of Guinea and discharges its waters into the Bight of Benin by way of a large delta in southern Nigeria. The Congo basin occupies an immense area of 750 000 km2, surrounded by Pre-Cambrian uplands. The alluvial floor of the saucer-shaped basin is flat, and marshes and swamps comprise a large proportion of the total area. The highlands and plateaus along the rim are low to the west and north and higher to the south. To the east, they merge with the mountains of the Great Rift Valley of East Africa (Gann & Duignan 1972; Hance 1975; Grove 1978; Hamilton 1989).

scholarly journals Incursion of Foot-and-Mouth Disease (FMD) Serotype O East Africa Topotype -3 (O/EA-3) in Nigeria

2021 ◽  
Vol 41 (1) ◽  
pp. 23-31
Author(s):  
H.G. Ularamu ◽  
J.O. Ibu ◽  
J.N. Abenga ◽  
D.D. Lazarus ◽  
Y.S. Wungak ◽  
...  
Keyword(s):  
East Africa ◽  
Animal Movement ◽  
Central Africa ◽  
Foot And Mouth Disease ◽  
West African ◽  
Mouth Disease ◽  
Sub Saharan Africa ◽  
Complex Nature ◽  
Foot And Mouth ◽  
West And Central Africa

Foot-and-mouth disease (FMD) is an endemic transboundary animal disease that affects livestock health across most of sub-Saharan Africa. Since the first official report of FMD in Nigeria in 1924, serotypes O, A, SAT 1 and SAT 2 have been documented within the  country. Molecular epidemiology has been used to trace the origin of FMD outbreaks in the case of animal movement, inter-species transmissions and trans-continental introductions. Phylogenetic analyses of VP1 nucleotide sequences of the twelve isolates (n=12) provide evidence for the presence of type O/EAST AFRICA 3 (EA-3) in Nigeria. The epidemiological situation of FMD in Nigeria and other West African countries is further complicated by the emergence of the O/EA-3 lineage that is causing new outbreaks in the region in addition to the West Africa (WA) topotype that has been known to be in circulation in Nigeria and other parts of West African and  Central African regions. These recent development in west and central Africa, indicates the dynamic and complex nature of FMD epidemiology in the region and this is not un-connected to the nomadism in the region. In addition the un-restricted animal movement across the porous border in the region in search of pasture and water for their animal has contributed to the spread of diseases across  the region. From the results the phylogenetic analysis of the O/EA-3 has close identity and was closely related to O/EA-3 from the 2009 outbreak in Sudan. Therefore, based on these findings a sustained surveillance is required to yet understand the epidemiology of FMD  in West and Central Africa that will inform the type of vaccine and target areas in other to control the disease. The need to restrict animal movement across the border should be put in place and where necessary all animals that must move from one point to another  must have proper evidence of vaccine certification before it should be allow access into the area. Finally for effective FMD control, regional vaccination and surveillance should be advocated and it should be backed by law. The need to have FMD vaccination at national as well as regional FMD control policy is strongly advocate for effective FMD control in Nigeria and across the regions. Key words: Topotype, West African; FMD and Nigeria

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