Humans as Omnivores

[BURN]

How and when did humans begin eating meat? As primates, naturally we'd have teeth of herbivores. I believe the change had to do with cold weather and lack of food during migration... but how can an animal just begin a diet on meat. Is it healthy? Could a Gorilla turn to eating meat in an instance of life or death?

Edited August 19, 2008 by BURN

[ajb]

Chimpanzees hunt and eat smaller primates. As for gorillas, they seem to docile and peaceful to become hunters.

[Sisyphus]

I don't know the answer to your main question. However, I'm sure, for example, gorillas could eat meat. They're not adapted to hunt, and it probably would be a pretty unhealthy diet for them, they'd have digestive problems, etc. But in a life or death situation, yeah. It's just calories and nutrients.

 

Also, just because we are primates doesn't mean our ancestors were ever strict herbivores. That seems to be the exception rather than the rule.

[CDarwin]

Why humans eat meat is relatively simple. How and when is generally where it gets complicated. It comes down to protein.There's no such thing as a truly 'frugivorous' primate, one that only eats fruit. All primates must consume either animal matter or leaves for the protein. Now, below about 500g, called Kay's Threshold, you can get away with just insect matter, but above that, it's principally leaves. However, once you reach a certain size, like that of apes, there's a choice to make in order to get enough protein. Go the gorilla direction of intensive folivory, or supplement your diet with meat, as chimpanzees and to some extent orangutans do. The bigger your size, the more meat you need, and the fewer leaves in your environment, the more meat you need. Now, early humans were at the same time getting larger and moving into relatively more open (less leafy) environments, both of which would require a greater concentration of animal protein to replace the lost leaves. Meat is also a wonderful source of calories, but that's probably just a bonus to the necessary protein it provides.

 

I wouldn't call primate's teeth those of a "herbivore," though, by the way. For one thing, the term is most precisely applied to grass-eaters, and only one kind of primate, the gelada, does that. But even if you just take to mean "vegetarian," primates are, as a group, generalists. We have pretty all-purpose dentition.

 

I don't know the answer to your main question. However, I'm sure, for example, gorillas could eat meat. They're not adapted to hunt, and it probably would be a pretty unhealthy diet for them, they'd have digestive problems, etc. But in a life or death situation, yeah. It's just calories and nutrients.

 

They also get high cholesterol really easily and develop heart problems. They do eat insects and occasionally birds eggs and the like, though.

Edited August 27, 2008 by CDarwin
multiple post merged

[Willa]

Umm, I think I watched a documentary that said that, before humans ate meat, we scavenged bone marrow from dead animals. (Hm, would bone marrow be considered a form of meat? Maybe. It doesn't fit in any other nutritional group.)

[CDarwin]

Umm, I think I watched a documentary that said that, before humans ate meat, we scavenged bone marrow from dead animals. (Hm, would bone marrow be considered a form of meat? Maybe. It doesn't fit in any other nutritional group.)

 

Nutritionally, it's the same stuff, but I would doubt that sequence. Early humans (which is an admittedly vague category) probably did scavenge bone marrow before they started consuming, say, ungulate flesh in large quantities, but before even that I'd say they were exploiting the various small mammals and lizards and birds they discovered while foraging for other foods. It's what chimpanzees, for example, do.

[MedGen]

I think an interesting development in our eating habits was cooking meat rather than just eating it raw. I expect it has some basis in destroying parasites and other pathogens, thus being safer to eat. Does anyone have any idea how this developed though? I assume it came after fire was discovered obviously, but did start our culturally then spread?

[iNow]

Does anyone have any idea how this developed though? I assume it came after fire was discovered obviously, but did start our culturally then spread?

It's certainly open to debate. We spoke about it here:

 

http://www.scienceforums.net/forum/showthread.php?t=33045

[CDarwin]

I think an interesting development in our eating habits was cooking meat rather than just eating it raw. I expect it has some basis in destroying parasites and other pathogens, thus being safer to eat. Does anyone have any idea how this developed though? I assume it came after fire was discovered obviously, but did start our culturally then spread?

 

It might have been done before controlled fires were made, on an opportunistic basis. I don't suppose there's anyway to possibly know.

[pioneer]

If I was to guess, humans began to eat meat sometime during the last ice age. The most logical scenario resulted from the affects of global cooling which meant less rain and cooling temperature. The result was less plant growth, drought and brush and forest fires. It may have been simple like, while scavenging for their veggie food in the rubble, they came across cooked animals. It smelled good and being hungry some began to eat. After that they gradually recognized these were animals, which were plentiful, since many can get by with scrub food.

 

Hunting would have been easy at first because humans were not a natural enemy to any animal, so most other animals had little fear when then they approached. But as they hunted more, the animals began to learn to avoid them, causing the pre-human hunting skill level to need to gradually rise. Harnessing fire may have been nothing more than keeping a pile of embers going from a forest fire. And then placing their animal booty into the fire to simulate those original tasty meals. This also evolved with time due to the requirement of more wandering to catch the animals who were now being more evasive. They had to learn to transport and then make fire.

[CDarwin]

You know, the scenario is a bit fanciful, but after looking up some things, your chronology doesn't seem horrible. Although I still want to point out that consuming meat of any kind and hunting large game are two very different things that almost certainly didn't happen at the same time. But the latest ice age started up around 2.6 million years ago, in the Pliocene, and by 2.5 million we see the Oldowan industry of stone tools, which show the first solid evidence of humans processing at least some meat from sources large enough to need processing with choppers (i.e. bigger than a squirrel). The origin of big game hunting is somewhat more controversial, but it is certain that it was a typical human trait by at least the time of the neanderthals, in the late Pleistocene. Basically, more open forests and scrubland = fewer edible leaves = a need to include more meat in the diet for the protein and also probably the calories.

Edited August 29, 2008 by CDarwin

[JeMoKn]

For me, I think that this "carnivorism" started when the early humans felt that they did not have enough strength (protein) from eating the plants, so they thought of eating primary/secondary consumers to see if they could achieve any more meat in them.

 

This is what I think, and it's basis is the Nitrogen cycle.