What spread as a result of the bantu migrations

The Bantu migrations had a vast influence on the development of Africa. The Bantu peoples passed on many concepts to the rest of Sub-Saharan Africa. Originating from Nigeria in the Niger River Valley, the Bantu migrated south and then spread to both the east and west. The Bantu laid the foundation for Sub-Saharan African societies. They spread agriculture, animal domestication, iron metallurgy, and cultural development throughout southern Africa. Various forms of government have developed as a result of the Bantu migrations. They also contributed to the start of many societies, including the Swahili city states. The adaptations the Bantu people learned, especially the making of iron, helped them to expand and spread their discoveries.

i need the diagram.

it made them more prductive and efficent but with the change of polcies less and les got into the navy