The bit about teeth is actually based on work by Weston A Price. He managed to catch photos of many tribes right as they transitioned into the then modern diet

The bit about teeth is actually based on work by Weston A Price. He managed to catch photos of many tribes right as they transitioned into the then modern diet in the early 20th century. He was also a dentist, which is why he focused on teeth. Focusing on teeth is important because 1. Cavities kill. 2. Teeth are a good proxy for general health. The bit about morbidity is bog standard anthropological information from any university. Quick googling for “hunter gatherer mortality” brings up plenty of sources. I personally focus on pre-history, since early “civilization” was awful. We’ve only recently climbed out of the low life expectancies that started with the advent of farming.