Asian Homo Erectus skulls (pre-dating the modern Homo Sapien migration out of Africa) frequently have shovel incisors.
Modern asian Homo Sapien skulls
after erectus was replaced by the modern African humans also frequently have shovel incisors. This contradicts the Out-of-Africa theory - but don't talk about it 'cuz that would hurt a lot of people's feelings.
So does this book. Don't read it.