HORTICULTURE

Detailed explanation-1: -Thought to descend from Berber nomads, the Tuareg first appeared in the Sahara in the 7th century as nomadic herders of camels, goats and sheep. Within centuries, though, they became known for a much more lucrative profession: the trans-Saharan trade caravans.

Detailed explanation-2: -One of the most ancient forms of herding is nomadic herding. Nomadic herders roam in small tribal or extended family groups and have no home base. Nomads live in arid and semiarid parts of Africa, Asia, and Europe, and in the tundra regions of Asia and Europe. In Africa, nomads herd cattle, goats, sheep, and camels.

Detailed explanation-3: -All this has been known for decades. But between 8, 000 and 4, 500 years ago, something strange happened: The transition from humid to dry happened far more rapidly in some areas than could be explained by the orbital precession alone, resulting in the Sahara Desert as we know it today.