Banjo playing is a form of devolution. (Just kidding).

Africa had antecedent instruments as Susan has suggested. The Kora is older.
The Akonting is probably the most recent antecedent.

The "bania" and the "banjar" probably emanate from Senegambia.

The first Human Ancestor probably played the "mouth bow" which has been attributed to Neanderthal man.