They Lived Before Adam ((Prehistoric Origins of the Igbo The Never Been Ruled))

They Lived Before Adam is a book by Catherine Acholonu that presents a controversial thesis about the Igbo people's prehistoric origins as the ancestors of humanity, predating the figure of Adam. The book argues this, drawing on her research into the inscriptions on the Ikom monoliths, cave art, and linguistic analysis, and is the second in her series on African origins. It also explores the Igbo's pre-colonial "never-been-ruled" political system. 
Central Thesis: The book proposes that Igbo civilization is older than what is traditionally taught, with origins stretching back 1.6 million years to the prehistoric period, and that the Igbo people were the ancestors of all humankind.