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Orange:       Caridial and Impressoceramics 
Brown:        Neolithic in Capsian tradition 
Light Green:  Sahara-Sudan cultures (Khartoum culture, Shaheinab culture) 
Red:          Neolithic of the Niger 
Purple:       Levant - Old Neolithic (Fayum Neolithic, Merimde) 
Green:        Upper Egyptian Neolithic (Badari)

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Originally posted by zarahan:



The map above ... shows the Sahel stretching across Africa. Questions:

--What other parts of Africa did the Sahel contribute to in terms of peopling and culture?

--What is the relationship between the Sahel and the Sahara?

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Posts: 8014 | From: the Tekrur in the Western Sahel | Registered: Feb 2006  |  IP: Logged | 

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Originally posted by zarahan:
Could be. I remember someone on the forum referring
to the 'Sahelian" roots of African Americans but
can't find the thread - and wonder if indeed
"Sahelian roots" is the case.

Question for the experts:
what is the percent breakdown of DNA in Egypt?

Overall, how much Haplogroup "E" versus everything else?

And what is the everything else?

The answer is probably buried somewhere among the huge number of studies but just looking for a straightforward breakdown. Isn't E predominant OVERALL in Egypt?

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Posts: 1080 | Registered: Aug 2008  |  IP: Logged | 

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Could be. I remember someone on the forum referring
to the 'Sahelian" roots of African Americans but
can't find the thread - and wonder if indeed
"Sahelian roots" is the case.

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Posts: 3085 | Registered: Jan 2008  |  IP: Logged | 

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Originally posted by Djehuti:
But as others have pointed out, it shouldn't be forgotten that the Sahara did not always exist and North Africa up to the Mediterranean coasts was green and fertile savannah. That being the case, there was no 'sahel' region to speak of? Was there not??

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Posts: 8014 | From: the Tekrur in the Western Sahel | Registered: Feb 2006  |  IP: Logged | 

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History of Desertification in Sahara and Sahel

Climate of the Sahel and the Sahara has changed greatly over the past 11,000 years since the end of the last ice age. The Sahara has expanded and contracted, changing the course of civilizations.

. . . .

The changing climate first attracted people to the Sahara as rainfall increased abruptly throughout the region beginning about 10,500 years ago (8,500 BC) at the end of the Younger Dryas.

Then increasing drought drove them southward into the modern Sahel as the rains became less frequent beginning about 7,200 years ago.

By 5,500 years ago (3,500 BC) the Sahara had returned to full desert conditions. It appears that many who left the Sahara settled in the Nile valley about 5,500 years ago, setting the stage for the First Dynasty starting with the reign of King Narmer in 3,000 BC (5,000 years ago).

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(A) During the Last Glacial Maximum and the terminal Pleistocene (20,000 to 8500 BC), the Saharan desert was void of any settlement outside of the Nile valley and extended about 400 km farther south than it does today.

(B) With the abrupt arrival of monsoon rains at 8500 BC, the hyper-arid desert was replaced by savannah-like environments and swiftly inhabited by prehistoric settlers.

During the early Holocene humid optimum, the southern Sahara and the Nile valley apparently were too moist and hazardous for appreciable human occupation.

(C) After 7000 BC, human settlement became well established all over the Eastern Sahara, fostering the development of cattle pastoralism.

(D) Retreating monsoon rains caused the onset of desiccation of the Egyptian Sahara at 5300 BC Prehistoric populations were forced to the Nile valley or ecological refuges and forced to exodus into the Sudanese Sahara where rainfall and surface water were still sufficient.

The return of full desert conditions all over Egypt at about 3500 BC coincided with the initial stages of pharaonic civilization in the Nile valley.
From Kuper and Kröpelin (2006).

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Since 3,000 BC the Sahel has had periods of more rain followed by periods of drought at intervals of 1,500 ± 500 years.

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Posts: 8014 | From: the Tekrur in the Western Sahel | Registered: Feb 2006  |  IP: Logged | 

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Originally posted by alTakruri:

I found variance in chronology for Saharan climate
phases but am offering the below from Robert Stewart's
Environmental Science in the 21st Century as a rough guide.

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History of Desertification in Sahara and Sahel

Climate of the Sahel and the Sahara has changed greatly over the past 11,000 years since the end of the last ice age. The Sahara has expanded and contracted, changing the course of civilizations.

. . . .

The changing climate first attracted people to the Sahara as rainfall increased abruptly throughout the region beginning about 10,500 years ago (8,500 BC) at the end of the Younger Dryas.

Then increasing drought drove them southward into the modern Sahel as the rains became less frequent beginning about 7,200 years ago.

By 5,500 years ago (3,500 BC) the Sahara had returned to full desert conditions. It appears that many who left the Sahara settled in the Nile valley about 5,500 years ago, setting the stage for the First Dynasty starting with the reign of King Narmer in 3,000 BC (5,000 years ago).

quote:

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(A) During the Last Glacial Maximum and the terminal Pleistocene (20,000 to 8500 BC), the Saharan desert was void of any settlement outside of the Nile valley and extended about 400 km farther south than it does today.

(B) With the abrupt arrival of monsoon rains at 8500 BC, the hyper-arid desert was replaced by savannah-like environments and swiftly inhabited by prehistoric settlers.

During the early Holocene humid optimum, the southern Sahara and the Nile valley apparently were too moist and hazardous for appreciable human occupation.

(C) After 7000 BC, human settlement became well established all over the Eastern Sahara, fostering the development of cattle pastoralism.

(D) Retreating monsoon rains caused the onset of desiccation of the Egyptian Sahara at 5300 BC Prehistoric populations were forced to the Nile valley or ecological refuges and forced to exodus into the Sudanese Sahara where rainfall and surface water were still sufficient.

The return of full desert conditions all over Egypt at about 3500 BC coincided with the initial stages of pharaonic civilization in the Nile valley.
From Kuper and Kröpelin (2006).

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Since 3,000 BC the Sahel has had periods of more rain followed by periods of drought at intervals of 1,500 ± 500 years.

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[/QB]

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Posts: 5905 | From: The Hammer | Registered: Aug 2008  |  IP: Logged | 

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Originally posted by MindoverMatter718:
Greening Of The Sahara Desert Triggered Early Human Migrations Out Of Africa

ScienceDaily (Nov. 9, 2009) — A team of scientists from the NIOZ Royal Netherlands Institute for Sea Research and the University of Bremen (Germany) has determined that a major change in the climate of the Sahara and Sahel region of North Africa facilitated early human migrations from the African continent. The team's findings will be published online in the Nov. 9th installment of Early Edition of the Proceedings of the National Academy of Sciences USA. Among the key findings are that the Sahara desert and the Sahel were considerably wetter around 9,000, 50,000 and 120,000 years ago than at present, allowing for the growth of trees instead of grasses.


Dust in marine sediment cores

The researchers studied marine sediments covering nearly 200,000 years collected from the seafloor off the coast of Guinea in West Africa. Strong off-shore winds transport large volumes of dust from the Sahara and Sahel to the study area. Mixed in with the dust are plant leaf waxes, which are blown long distances across the African continent to the Atlantic Ocean, where they were ultimately deposited on the seafloor at about 3 km depth.

Over thousands of years, layers of sediment accumulated on the seafloor, each layer containing evidence of past environmental conditions in Northern Africa. The plant leaf waxes are resistant to degradation and when trapped within layers of sediment, they can be very well-preserved for millions of years.

Vegetation changes in the Sahara

Based on analysis of plant leaf waxes the researchers could determine the relative importance of trees and grasses in the Sahara and Sahel regions. Trees generally require more water to survive than do tropical grasses, and so by analysing the plant leaf waxes to determine if they were produced by trees or grasses, the scientists could examine past precipitation changes in tropical Africa over the last 200,000 years.

During three discrete periods, ca. 120,000-110,000 years, 50,000- 45,000 and 10,000-8,000 years ago, substantially more trees grew in Sahara and the Sahel, indicating significantly wetter conditions than at present. The two oldest periods exactly coincide with times when the earliest humans were migrating out of East Africa to northern Africa, the Middle East, Asia and eventually Europe. At these times, the wetter conditions in central North Africa likely enabled humans to cross this normally inhospitable region, allowing them to migrate into other continents. When climate in the Sahara and Sahel turned dry again, humans were forced out of these areas causing genetic and cultural changes in already inhabited regions such as Northern Africa and the Middle East.

Changes in ocean circulation caused a wetter Sahara

The researchers also looked for the causes of these major climate shifts to much wetter conditions in the Sahara and found that they were indirectly related to an increase in the strength of the major current system, the Atlantic Overturning Circulation (AOC). The researchers could assess the strength of this current by analysing fossilized tiny shells of small animals (benthic foraminifera).When the intensity of the AOC changes, this leads to changes in the chemical composition of the deep water masses, which is then reflected in the shells of benthic foraminifera.

The researchers found that when the AOC weakened, more grasses were present in central North Africa indicating a drier climate. Likely, the weakening of the AOC was caused by increased freshwater input to the high-latitudes, leading to less saline surface waters. This freshwater input also caused surface cooling in these regions, in turn leading to movement of cold air from the high-latitudes to the tropics, and causing drier conditions in central North Africa.

Thus, early human migrations from the African continent were likely triggered by events originating far away in the North Atlantic.

This research project was funded by the Netherlands Organisation for Scientific Research (NWO) and the Deutsche Forschungsgemeinschaft Research Centre/Excellence Cluster "The Ocean in the Earth System"

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Posts: 6572 | From: N.Y.C....Capital of the World | Registered: Jun 2008  |  IP: Logged | 

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Originally posted by .Charlie Bass.:
As for possible population relationships........


http://content.karger.com/ProdukteDB/produkte.asp?Doi=91489


Relationship of the Sickle Cell Gene to the Ethnic and Geographic Groups Populating the Sudan
Abdelrahim O. Mohammeda, Bekhieta Attallab, Fathya M.K. Bashira, Fatima E. Ahmedc, Ahmed M. El Hassanc, Gafar Ibnaufd, Weiying Jiange, Luigi L. Cavalli-Sforzae, Zein Al Abdin Karrarb, Muntaser E. Ibrahimc

Departments of
aBiochemistry,
bPediatrics, Faculty of Medicine University of Khartoum,
cInstitute of Endemic Diseases, University of Khartoum, and
dFederal Ministry of Health, Khartoum, Sudan;
eDepartment of Genetics, School of Medicine Stanford University, Stanford, Calif., USA


The presence of a geographical pattern in the distribution of the sickle cell gene (S gene) and its association with malaria is well documented. To study the distribution of the S gene among various ethnic and linguistic groups in the Sudan we analyzed a hospital-based sample of 189 sickle cell anemia (SCA) patients who reported to the Khartoum Teaching Hospital between June 1996 and March 2000 and 118 controls with other complaints, against their ethnic and linguistic affiliations and geographic origin. Electrophoresis for hemoglobin S and sickling tests were carried out on all patients and controls as a prerequisite for inclusion. The majority of patients (93.7%) belonged to families of single ethnic descent, indicating the high degree of within-group marriages and thus the higher risk of augmenting the gene. SCA was found to be predominant among the Afro-Asiatic-speaking groups (68.4%) including nomadic groups of Arab and non- Arab descent that migrated to the Sudan in various historical epochs. Those patients clustered in western Sudan (Kordofan and Darfur) from where 73% of all cases originate. The proportion of patients reporting from other geographic areas like the south (3.1%), which is primarily inhabited by Nilo-Saharan-speaking groups (19% of the whole sample) who populated the country in previous times, is disproportionate to their total population in the country (2 = 71.6; p = 0.0001). Analysis of the haplotypes associated with the S gene indicated that the most abundant haplotypes are the Cameroon, Benin, Bantu and Senegal haplotypes, respectively. No relationship was seen between haplotypes and the various hematological parameters in the sub-sample analyzed for such association. These results provide an insight into the distribution of the sickle cell gene in the Sudan, and highlight the strong link of the middle Nile Valley with West Africa through the open plateau of the Sahel and the nomadic cattle herders and also probably the relatively young age of the S gene.

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Posts: 5905 | From: The Hammer | Registered: Aug 2008  |  IP: Logged | 

posted                      

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Originally posted by MindoverMatter718:

quote:

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Originally posted by MindoverMatter718:
Greening Of The Sahara Desert Triggered Early Human Migrations Out Of Africa

ScienceDaily (Nov. 9, 2009) — A team of scientists from the NIOZ Royal Netherlands Institute for Sea Research and the University of Bremen (Germany) has determined that a major change in the climate of the Sahara and Sahel region of North Africa facilitated early human migrations from the African continent. The team's findings will be published online in the Nov. 9th installment of Early Edition of the Proceedings of the National Academy of Sciences USA. Among the key findings are that the Sahara desert and the Sahel were considerably wetter around 9,000, 50,000 and 120,000 years ago than at present, allowing for the growth of trees instead of grasses.


During three discrete periods, ca. 120,000-110,000 years, 50,000- 45,000 and 10,000-8,000 years ago, substantially more trees grew in Sahara and the Sahel, indicating significantly wetter conditions than at present. The two oldest periods exactly coincide with times when the earliest humans were migrating out of East Africa to northern Africa, the Middle East, Asia and eventually Europe. At these times, the wetter conditions in central North Africa likely enabled humans to cross this normally inhospitable region, allowing them to migrate into other continents. When climate in the Sahara and Sahel turned dry again, humans were forced out of these areas causing genetic and cultural changes in already inhabited regions such as Northern Africa and the Middle East.


Thus, early human migrations from the African continent were likely triggered by events originating far away in the North Atlantic.

This research project was funded by the Netherlands Organisation for Scientific Research (NWO) and the Deutsche Forschungsgemeinschaft Research Centre/Excellence Cluster "The Ocean in the Earth System"

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Posts: 5905 | From: The Hammer | Registered: Aug 2008  |  IP: Logged | 

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Originally posted by MindoverMatter718:

Greening Of The Sahara Desert Triggered Early Human Migrations Out Of Africa

Among the key findings are that the Sahara desert and the Sahel were considerably wetter around 9,000, 50,000 and 120,000 years ago than at present, allowing for the growth of trees instead of grasses...


During three discrete periods, ca. 120,000-110,000 years, 50,000- 45,000 and 10,000-8,000 years ago, substantially more trees grew in Sahara and the Sahel, indicating significantly wetter conditions than at present. The two oldest periods exactly coincide with times when the earliest humans were migrating out of East Africa to northern Africa, the Middle East, Asia and eventually Europe...

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Posts: 7516 | From: Somewhere on Earth | Registered: Jan 2008  |  IP: Logged |