Quote:
Originally Posted by Riloux Gartier
The human brain began to grow when humans had to deal with increased social interaction. That social interaction tends to follow hunting, since unlike with gathering, huge ammounts of calories could be ingested in what were occasional bonanzas of meat. This led to an increase in the complexity of social behaviors, including finding how to rise in rank with procurement of meat and other animal products, which were rare, and a luxury... since meat was not nessesary for growth or development; but it was a rare case of having large ammounts of fats+protein calories for the group. It was the gatherings that resulted from harvests (of veggies) and finding meat that led to increased brain complexity, not the item being eaten. By that logic lions would be the most intelligent (at things like math and reading of all) animal on earth.
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Riloux Gartier, I am confused by your quote above, which seems to point out that you feel hunting animals inspired social interactions that triggered increased human intellect, yet meat-eating wasn't so important since the social interaction itself was the key factor in the evolution of our human intellect.
If it were true that meat-eating partly encouraged the social interactions that were an important force in human evolution (which is under debate), then it sounds as if you are stating exactly what Tore stated: that meat-eating had an important evolutonary role.
You suggest that meat-eating may not have been of primary importance in the development of traits we associate with Homo sapiens that distinguish us from our ancestors, such as smaller teeth, and this is true. Some scientists hypothesize that the ability of early hominids to control fire and use it to cook tubers may have selected for many of the traits that distinguish humans from earlier ancestors (australopithecines). After all, human ancestors were hunting animals and eating meat for millions of years without developing the extent of social, intellectual, and physical traits humans have, suggesting that meat-eating was not by itself a driving force in development of these traits:
Quote:
Of Tubers, Fire and Human Evolution - NYTimes.com
Dr. Wrangham's group theorizes that a population of australopithecines, the apelike ancestors of Homo erectus, gained control of fire and began cooking tubers and roots in East Africa about 1.9 million years ago. Within several hundred generations -- a short time in evolutionary terms -- the australopithecines had evolved into Homo erectus. ''Evolution is driven by a cultural event: the capture of fire,'' Dr. Wrangham said.
Homo erectus, whose early form in Africa is sometimes called Homo ergaster, is distinguished by physiological and neurological changes from its australopithecine forebears, including a considerably larger brain, smaller teeth and an upright gait. Females also began to form individual pair bonds with males within large social groups, Dr. Wrangham theorizes, largely to prevent other males from stealing food they collected and prepared around a fire.
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So, it is very possible that meat-eating was not a key factor in the development of human traits such as pair-bonding and smaller teeth and even cleverer, social brains. However, simply because carnivores like lions, whom you mention, are not as intellectual as we are does not mean that meat-eating did
not play an important role in human evolution during the past.
Homo sapiens and our hominid ancestors, Homo erectus and before them, australopithecines, naturally do/did have the ability to digest meat; therefore, I view the ability to digest meat as "natural" and as being an adaptive, beneficial trait that conferred reproductive advantages on those who possessed it. This is the reason humans are still biologically omnivores.
Here's an article in the journal
Human Evolution that points out that humans have the capacity to eat mostly plant-based diets
or mostly meat-based diets.
Quote:
SpringerLink - Journal Article
Gut measurements of primate species do not support the contention that human digestive tract is specialized for meat-eating, especially when taking into account allometric factors and their variations between folivores, frugivores and meat-eaters. The dietary status of the human species is that of an unspecialised frugivore, having a flexible diet that includes seeds and meat (omnivorous diet). Throughout the various time periods, our human ancestors could have mostly consumed either vegetable, or large amounts of animal matter (with fat and/or carbohydrates as a supplement), depending on the availability and nutrient content of food resources.
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If the ability to digest meat were a neutral trait (rather than a beneficial trait that increases reproductive fitness), then we would expect to see among humans some who have lost the ability to digest meat (making them obligate herbivores). Since this is not the case, I conclude that the ability to digest meat has been an important trait among humans during evolutionary history; those who lacked this ability would have been less likely to "exploit their environment" and produce as many children as those of our ancestors who ate whomever they could catch while also gathering edible plant material.
Most importantly, I feel the exact role of meat-eating in human evolution is not important now for deciding whether people can or should be vegetarians, which I view to be a health and ethical issue.
Quote:
Originally Posted by Riloux Gartier
Health is relative to the time period. It changes with the advent of new Knowledge/technology/education The average "Healthy" human in the 1800s would very rarely live to see 50.
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In the not-too-distant past, before vitamin B-12 was synthesized by organic chemists, humans would not have had the ability to survive at all as vegans, since the concentration of this essential vitamin in free-living bacteria (upon leaves or in soil on plants that are eaten) is very low. In order to survive, our recent ancestors appear to have needed a more plentiful source of vitamin B-12 than soil or plant microbes provide. When humans moved into areas (such as Norway) where edible plant material was perhaps scarce but animals were plentiful, humans could only survive by eating diets heavy with animal parts.
Some animals (such as cows) are able to obtain sufficient vitamin B-12 through their gut bacteria. This is not the case for humans, nor for other primates:
Quote:
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"Non-human primates typically eat small amounts of eggs, insects, and small vertebrates and/or soil. Gorillas, possibly the closest to vegan of all the species closely related to humans, eat insects, and sometimes feces." http://www.veganhealth.org/b12/animal
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I accept that natural selection has resulted in humans needing an exogenous source of vitamin B-12. I feel this has no bearing on whether or not we choose to be vegan, Riloux Gartier (assuming we have access to synthetic vitamin B-12).
Tore, thanks for the video documentary suggestion! I'll try to find it and view it. That sounds interesting!