Zeinab Badawi continues her journey through the history of human development travelling to meet the Maasai of east Africa - one of the best known of the continent’s ethnic groups. They help explain how human beings began to domesticate animals and become pastoralists. Then in Zimbabwe with one lively farming family, Zeinab examines how humans also began to settle and make a living from farming. And she also looks at how the Iron Age transformed life in Africa and paved the way for the development of rich urban civilisations.