Gurey,
According to this, African sheep first entered Africa through the northeast and the Horn. There could have been more than one entry. It seems likely they would have arrived with Eurasian immigrants.
http://archaeology.about.com/od/shthrou ... istory.htm
"Domestic sheep probably entered Africa in several waves through northeastern Africa and the Horn of Africa, the earliest beginning about 7700 BP. Four types of sheep are known in Africa today: thin-tailed with hair, thin-tailed with wool, fat-tailed and fat-rumped. North Africa has a wild form of sheep, the wild Barbary sheep (Ammotragus lervia), but they don't appear to have been domesticated or made up part of any domesticated variety today.
The earliest evidence of domestic sheep in Africa is from Nabta Playa, beginning about 7700 BP; sheep are illustrated on Early Dynastic and Middle Kingdom murals and they appear in eastern Africa about 4500 BP (see Horsburgh and Rhines)."
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Camels are late-comers. And it does look like they arrived with Islam, which makes a lot of sense, given Samaale history.
http://quatr.us/economy/camels.htm
"But around the beginning of the Islamic empire, maybe about 500 AD, somebody in West Asia invented a good pack saddle for camels. After that, people began to use camels as pack animals more and more.
In Africa, beginning around 1000 AD, camels made it much easier to cross the Sahara desert, so people could trade between West Africa and North Africa. This started great trade routes which traders still use today."
http://archaeology.about.com/od/Domesti ... -Camel.htm
"Dromedaries have been identified at sites in southeastern Arabia beginning between 5000-6000 years ago. The site of Mleiha in Syria includes a camel graveyard, dated between 300 BC and 200 AD. Finally, dromedaries from the Horn of Africa were found at the Ethiopian site of Laga Oda, dated 1300-1600 AD."
By these times, sea-faring had greatly improved and the economic benefit of moving camels from southeast Arabia to Africa was clear.
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I don't understand why you think the presence of Cushitic languages in Tanzania negates the probability of Khoisan in Somalia. The Hadza and Sandawe are in central Tanzania.
http://www.sarada.co.za/traditions/afri ... rn_africa/
"Recent studies have shown that the Hadza and Sandawe are genetically distinct from their farmer and pastoralist neighbours. They, together with the southern African San, retain some of the oldest genetic signatures of all the world’s peoples. On the matter of if or when these click speaking populations were related, the genetic evidence is very clear. A series of studies have shown that the East African and Southern African click-speaking groups have remained genetically isolated from each other for at least the last 70,000 years. This implies that these groups have remained isolated in their respective parts of Africa for a remarkable length of time, presumably separated from each other by the varied Pygmy groups who made the geometric tradition rock art spread across the intervening area of central Africa. We are therefore left with the inescapable conclusion that it was the ancestors of the Hadza and the Sandawe and other related groups whose descendents no longer survive who made the Tanzanian rock art."
We need DNA on the Eyle and other hunting peoples in Somalia. The Eyle sit on an archaeological record which contains their pottery back to the late Neolitic and an earlier record back to the Paleolithic. Several lists of Khoisan relatives contain the Aweer, Eyle and Midgan. It's time to make this definitive.
