In 1971 a book hit the shelves suggesting human evolution was driven by cannibalism. The book is The Beginning Was the End by Oscar Kiss Maerth.
The book proposes that early cannibalistic apes discovered the aphrodisiac effects of brains, and became addicted to them. However, the nutirent-rich brain matter inadvertently kickstarted evolution, leading to increased brain size and intelligence while causing the loss of body hair and our innate psychic abilities.
The book claims these advances ultimately caused de-evolution, leading us to be disconnected from nature and each other, suffering from distorted sexuality from hormone imbalances and driven insane by the pressures of our large brains inside our skulls.
Maerth foresees a return to cannibalism in the future, and cautions the reader to stay as far away from it as possible.