Based on human genetics, it is widely believed that prehistoric Africans who left the continent within the past 100,000 years are the ancestors of all non-African humans. But as communities began to form, especially in Egypt and the Middle East, these migrations were greatly reduced because the only land route out of the African continent is through the Sinai Peninsula. After the rise of civilization and the development of sailing, black Africans traveled to the Middle East, Europe, and Asia in a number of occupations. Many of these individuals settled in Europe and Asia and invariably intermarried with the local populations. Today, human genetic research suggests that mitochondrial DNA and Y chromosome haplotypes in Europeans and Asians have distant African ancestry. But these early migrations out of Africa are dwarfed by those associated with the Atlantic and Arab slave trades. Later, QD.