Discourage dividing the history of Africa into just three parts. He argues that this is an oversimplified way of looking at Africa's history. Since human sustenance began in Africa, our first impact on the African environment began as hunters and gatherers. We have reclaimed the land for game and desirable fruits. This obviously affected the populations we were consuming. We affected the physical environment when we burned meadows to attract game. We then move on to sheep farming (invented in the northern parts of Africa about 7 millennia ago); we raised and domesticated cattle, camels, goats and sheep. In doing so we have changed the African environment by altering a mix of plants or just grazing and herding herds at a single water source during dry seasons. We cause a decrease in crop diversity when we started practicing agriculture and encouraging specific crops like millet, sorghum and sorghum