Great Rift Valley, Africa

It is possible that we are not yet perfectly adapted to such a high carbohydrate diet. Some students of tooth decay point out that dental caries is rare among primitive Eskimos and the meat eaters of the Great Rift Valley in Africa. Many seem to feel that the human race made a mistake in giving up its primitive, carnivorous diets and that dental ailments are the price we have paid for adoption of carbohydrate foods (49). However this may be, all indications are that carbohydrates are here to stay. Indeed, unless science can provide some alternative that is not yet in sight, the growth of even United States population may be expected eventually to force us by stages up toward the 85% carbohydrate level of the orientals. 

One tentative theory for the absence of human fossils in the Pliocene Era is that a great drought in Central Africa forced the hominoids to become aquatic waders, isolated in the Afar GulfThis Gulf lies in the Rift Valley of Africa, south of the Danakil Alps. " °... 

Hecky, R. E. H. J. Kling, 1987. Phytoplankton ecology of the great lakes in the rift valleys of central Africa. Ergebn. Limnol. 25 197-228. 

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