There's large parts of the food world that are completely inaccessible to humans.
Most plant material (i.e. "fiber", digestible by e.g. cows), carion, most raw meat (if we ate what dogs ate, we'd have constant stomach issues...)
Most plant material (i.e. "fiber", digestible by e.g. cows), carion, most raw meat (if we ate what dogs ate, we'd have constant stomach issues...)
Humans have extremely acidic stomach acid (1.5 - 3.5 pH), close to that of vultures and dogs (1 - 2 pH).
Early humans and their predecessors, were very likely (at least partially) carrion feeders, and consumed raw meat for millions of years before they started cooking.
The use of tools made from stones to break open bones for marrow and to possibly butcher animals suggests that early humans exploited carcasses that they found or scavenged from other predators' kills. Marrow and brain tissue, which could be accessed by breaking open bones and skulls, are highly nutritious and would have been valuable food sources for early humans.
Over time, as hominins developed more sophisticated tools and techniques, they likely became more efficient hunters, gradually shifting from scavenging to actively hunting for their food. However, the practice of scavenging would have played a critical role in the dietary habits of early human ancestors and contributed to their evolutionary success.
https://academic.oup.com/bioscience/article/64/5/394/2754213