ANN ARBOR, Michigan—Archaeologist Raven Garvey conducted a study of digestives, the undigested plant matter in the stomachs of herbivores, and found that bison digestives may have contributed to human survival, according to a statement released by the University of Michigan. concluded that it may have played an important role in survival. diet of hunter-gatherers. She says that digestate from many species could have been a source of calories and nutrients such as carbohydrates, proteins and fats. group could consume enough protein and carbohydrates from the digestate of one bison to meet USDA nutrition recommendations for 3 days without eating any other food. “Failure to account for this undervalued resource could have important consequences for research addressing key questions in evolutionary anthropology,” said Garvey. this resource. She says that if hunter-gatherers had access to sufficient digestives, the pressure to search for fresh vegetation would be alleviated, allowing them to devote their time to other activities instead.Hunter-gatherers? ”