Gut morphology and the avoidance of carrion among chimpanzees, baboons, and early hominids
S Ragir, M Rosenberg, P Tierno
Journal of Anthropological Research, 2000•journals.uchicago.edu
Meat-eating primates avoid scavenging for dietary protein and micronutrients even when carrion is relatively fresh. Chimpanzees, baboons, and modern hunter-gatherers supplement their diets of high-energy, low-protein fruit with protein obtained from leaves, insects, and animal prey. Most primates, especially leaf-eating primates, digest the cellulose cell walls of ingested plant material in a well developed caecum and/or large intestine through fermentation caused by enzymes released by their normal gut flora. The primate digestive strategy combines a rapid passage through the stomach and prolonged digestion in the ileum of the small intestine and caecum, and this combination increases the likelihood of colonization of the small intestine by ingested bacteria that are the cause of gastrointestinal disease. Carrion is very quickly contaminated with a high bacterial load because the process of dismemberment of a carcass exposes the meat to the bacteria from the saliva of the predator, from the digestive tracts of insects, and from the carcasses' own gut. Thus, the opportunistic eating of uncooked carrion or even unusually large quantities of fresh-killed meat by nonhuman primates or humans is likely to result in gastrointestinal illness. We propose that among meat-eating primates, carrion avoidance is a dietary strategy that develops during their lifetime as a response to the association of gastrointestinal illness with the ingestion of contaminated meat from scavenged carcasses. This has important implications for our understanding of early hominid behavior.
Fantastic paper, thanks for pointing to it. The story of pathogens, parasites, and meat is a really fascinating topic today. In the past researchers have tended to assume that meat is an almost unqualified good thing in the diet. It's rich in protein and fat, it's digestible, and it comes in some big sharable packages. But it comes with a substantial cost due to parasites and pathogens that infect prey animals and can be transmitted to carnivores. The cost is carried by our immune systems and likely spurred evolutionary change in these systems in early hominins. The growth of bacteria and (eventually) mold on carrion also adds to this burden.
Gut morphology and the avoidance of carrion among chimpanzees, baboons, and early hominids
S Ragir, M Rosenberg, P Tierno
Journal of Anthropological Research, 2000•journals.uchicago.edu
Meat-eating primates avoid scavenging for dietary protein and micronutrients even when carrion is relatively fresh. Chimpanzees, baboons, and modern hunter-gatherers supplement their diets of high-energy, low-protein fruit with protein obtained from leaves, insects, and animal prey. Most primates, especially leaf-eating primates, digest the cellulose cell walls of ingested plant material in a well developed caecum and/or large intestine through fermentation caused by enzymes released by their normal gut flora. The primate digestive strategy combines a rapid passage through the stomach and prolonged digestion in the ileum of the small intestine and caecum, and this combination increases the likelihood of colonization of the small intestine by ingested bacteria that are the cause of gastrointestinal disease. Carrion is very quickly contaminated with a high bacterial load because the process of dismemberment of a carcass exposes the meat to the bacteria from the saliva of the predator, from the digestive tracts of insects, and from the carcasses' own gut. Thus, the opportunistic eating of uncooked carrion or even unusually large quantities of fresh-killed meat by nonhuman primates or humans is likely to result in gastrointestinal illness. We propose that among meat-eating primates, carrion avoidance is a dietary strategy that develops during their lifetime as a response to the association of gastrointestinal illness with the ingestion of contaminated meat from scavenged carcasses. This has important implications for our understanding of early hominid behavior.
Fantastic paper, thanks for pointing to it. The story of pathogens, parasites, and meat is a really fascinating topic today. In the past researchers have tended to assume that meat is an almost unqualified good thing in the diet. It's rich in protein and fat, it's digestible, and it comes in some big sharable packages. But it comes with a substantial cost due to parasites and pathogens that infect prey animals and can be transmitted to carnivores. The cost is carried by our immune systems and likely spurred evolutionary change in these systems in early hominins. The growth of bacteria and (eventually) mold on carrion also adds to this burden.