VEGETARIAN, ken laming, kenneth laming, frugan, health, fresh food, raw food, famous vegetarian, vegan, nutrition, fitness,

EVOLUTIONWERE EARLY HUMANS VEGETARIAN?

 

MEAT-EATING & HUMAN EVOLUTION: (a review of research into diet and evolution).

Ironically, our greatest achievement as a species may be applying our enlarged brain and our technology to recreating the diet we instinctively ate a million years ago.

Imagine the primordial jungle. Imagine many kinds of primates, including anthropoids (chimps, gorillas and early humans) foraging for fruits and protein-rich leaves in the canopy of the arboreal forest. This story begins more than 55 million years ago but it has been the life-long study of Dr.Katherine Milton, professor of anthropology at the University of California. Her quest for links between diet and evolution is shared by Dr David Popovich, of nutritional sciences at the University of Toronto, who also sees a connection between diet and human development of vision, depth perception, memory, speech, dexterity and social behaviour.

We have been given the impression that our early ancestors were closer to carnivores than they were to plant eating animals. The degree of meat in the early hominid diet is a matter of controversy and the more conservative view sees evidence for including small amounts of meat in the ancestral diet through opportunistic foraging and scavenging. The ancestors in question lived long before any modern human predecessors. The National Geographic Society's recent report on Neanderthal life in glaciated Europe, for example, cites evidence of cannibalism and reliance on hunting for food. However, these primate cousins were relatively recent in hominid history. Our original ancestors predate them by eons, long before the last great ice age. The early hominids were much more similar to modern day chimpanzees and gorillas.

Most of us think of a chimp's life as being fairly carefree. Dr. Milton was surprised when she was observing a troupe of chimps and noticed that, instead of sitting around in the tree branches and eating what was nearby, they hurriedly sought out specific foods, rejecting a number of delicious looking leaves in order to move on. When they found an acceptable specimen, they did not gorge themselves. Instead, they seemed driven to obtain a mixture of fruits and leaves from a variety of plant species. On the spot, Dr. Milton decided to devote her career to studying how these animals met their nutritional needs.

Chimps in the wild today face many challenges to obtaining a sufficient variety of plant material - similar challenges were likely faced our distant ancestors. For starters, many plants have developed outer coatings to discourage hungry herbivores. These outer layers contain chemical compounds that taste terrible and sometimes are lethal.

In addition, the fibrous content of plants, which we call "fibre" or "roughage," resists breakdown by mammalian digestive enzymes. Excessive intake of fibre is troublesome because when fibre goes undigested, it provides no energy for the feeder. The trick is to do a better job of digesting the fibre. At the University of Toronto, David Popovich has been studying the micro-nutrient content of the wild vegetation consumed by gorillas. He has found that much of the energy and nutrient value that gorillas are able to derive from such a diet comes from colonic fermentation. Their studies on human subjects have shown that humans may also be able to rely on colonic fermentation. Thus, a diet consisting of substantial quantities of fruits, vegetables and nuts - no pasta or starches - will provide adequate protein, B-12 and amino acids (the building blocks of protein). Gorillas and chimpanzees have little trouble digesting cellulose thanks to the presence of the ciliate Troglodytella in their intestines. However, chimps and gorillas in captivity begin to lose their Troglodytella when they are fed cooked food. Thus, it is reasonable to assume that humans lost their intestinal cilia when they started cooking with fire.

While the amount of meat consumed by our distant ancestors is still debated, there is consensus that the Pleistocene diet consisted overwhelmingly of vegetable material. 

Another concern with such a diet is finding time to forage.  Primates cannot concentrate on just a few plant sources because, even if the fibre could be well-digested, many plant foods are low in one or more of the required nutrients, such as vitamins or amino acids.  Fruits tend to be rich in easily digested forms of carbohydrate and relatively low in fibre, and provide little protein.  Given that primates in the arboreal canopy do not cultivate protein-rich beans and vegetables, they rely heavily on efficient access to a wide variety of preferred fruits and leaves to achieve adequate protein.

Developing a better memory for the exact location of favoured trees, the shortest routes between them and a timetable for when they would likely be fruit-bearing would definitely favour survival.  A larger brain would no doubt support these activities as well as group communication.  Today, spider monkeys comb the forest for fruit by dividing into small, changeable groups. Their expanded mental capacity helps them recognize members of their own social unit and learn the meanings of different food-related calls.

The inherent complexities of the plant food niche could have been a factor in increasing the longevity of primates.  Neither apes nor humans can rely on their relatively poor senses of taste and smell to detect toxicity, so they require several years of adolescence to learn which foods are safe and nutritious.  This may be why humans are one of the longest living animals on earth.

Dr. Milton claims that the crafty Homo sapiens were better equipped to solve the dietary problems wrought by changing environmental conditions. Expansion of brain power in combination with growth in body size and reduction in the jaw and teeth, are evidence of achievement of a high quality diet.  Without the high quality diet, the increased body size simply produces a slow moving, fairly sedentary and unsociable ape, like present-day orangutans and gorillas.  Dental patterns among fossils of hominids support evidence of a high quality, plant-based diet.  The decreased mass of the jaw and teeth signify that either our ancestors were eating less fibrous, easier-to-chew foods or they were processing them to remove material that would be hard to digest.

Some researchers have proposed that modification in dental structures resulted partly from specialization in hunting and scavenging.  However, electron microscope examination of bones collected from early hominid sites reveals that our ancestors most likely scavenged bones that were already ravaged by carnivores.  While the amount of meat consumed by our distant ancestors is still hotly debated, there is consensus that the Pleistocene diet consisted overwhelmingly of vegetable material.  While chimpanzees are known to kill, this behaviour is not necessarily dietary but ritualistic and their diet is at least 94% plants and fruits.

Wild chimps take in 100 grams of fibre each day, much more than the 10 grams or less that the average North American ingests today.  Dr. Milton's studies have shown that the chimpanzee gut is strikingly similar to the human gut in the efficiency with which it processes fibre.  According to Dr. Milton, our digestive tract does not seem to be greatly modified from that of the common ancestor of apes and humans, which was undoubtedly a predominately herbivorous / fruitarian animal.

While there is no authoritative recommendation for the daily intake of fibre, the small amount ingested daily by most Canadians is far less than we need to remain healthy.  According to David Popovich, captive gorillas are dying in zoos of the same arterial sclerosis afflicting human cardiac patients because the zoos are unaware of the gorillas' reliance on fibre.  Dr. David Jenkins, known as the father of the "fibre movement" in Canada and Director of the Clinical Risk Factor Modification Centre at St. Michael's Hospital, continues to make a strong case for vegetarianism as the optimum human diet.

BIBLIOGRAPHY:

2002 Hans Dehmelt. What is the optimal diet of the anthropoid primate homo sapiens?(212 Kb pdf file) Department of Physics, University of Washington, Seattle, March 18, 2002

1993 Milton, Katherine. "Diet and Primate Evolution," Scientific American, pp. 86-93.

1996 Popovich, David. Interviews with graduate researcher in the Department of Nutritional Sciences at the University of Toronto to prepare this article (May, 1996).

1997 David G. Popovich, David J. A. Jenkins, et all. "The Western Lowland Gorilla Diet Has Implications for the Health of Humans and Other Hominoids." The Journal of Nutrition, Vol. 127, No. 10 October 1997, pp. 2000-2005.

1988 Potts, Richard. "On an early hominid scavenging niche." Current Anthropology, 29(1):153-155.

1984 "HOME BASES AND EARLY HOMINIDS." American Scientist, 72: 338-347.

1988 Shipman, Pat. Scavenging or hunting in early hominids: theoretical framework and tests. American Anthropologist.

1984 Stalh, Ann A. Brower. "Hominid dietary selection before fire." and Adrian Kortlandt, "Commentary," Current Anthropology 25(2): 151-168

The Diet of Early Humans

Vegetarianism and Archaeology

Derek Wall examines the "mighty hunter" myth of human ancestry from The Vegetarian, September/October 1988.

Derek Wall, B.Sc., studied archaeology at the Institute of Archaeology which is part of London University.

Archaeology and vegetarianism are, at first sight, a rather unlikely combination; most people if asked to consider the diet of our ancestors would tend to conjure up images of cavemen roasting mammoth steaks or early medieval monarchs spitting venison over a roaring fire, not a lentil in sight. Many academics have taken these simplistic visions to their logical and dangerous conclusion; to argue, that in the past we have eaten meat, therefore eating meat is 'natural' and that vegetarianism is an unhealthy regression to the period when we were full fruitarians and swung from tree to tree.

Perhaps even more disturbing is the view that we have only become human through eating meat, that according to people like Raymond Dart writing as long ago as the 1930s, it has only been through hunting, aggression and violence that we have eaten non-carnivorous rivals in the evolutionary battle of the fittest. According to Dart and others, changes in human and early hominid dentition show that our teeth adapted to chewing meat. Happily more recent investigation tells a different story; Dr Clifford Jolly suggests that the real evolutionary transition came when our ancestors left the tropical forests of central Africa and took to the open savannah, shifting from a diet made up mostly of fruit to one based on seeds and grains, our ancestors' teeth adapting to cope with the relatively hard particles that needed a lot of grinding down before they could be digested.

HUNTER-GATHERERS

Despite this, nutritionalist John Yudkin claims that for 99% of our existence we have been hunters with an 'ideal' diet, where …people tend to have a quite high proportion of meat.'  Yudkin goes on to draw the conclusion that we suffer nutritional problems today (especially allergies) only to the extent we have shifted from this all animal diet with the occasional root or tuber thrown in. A major pitfall associated with this line of reasoning is the fact that most illnesses are caused by over consumption of animal fats; heart disease, cancer, atherosclerosis and weight problems.  And again the archaeological evidence tells another story as does the existence of so-called 'hunters' in the modern world.

Groups such as the Kalahari bushmen and the Australian aborigines are not so much hunters as 'hunter-gathers', gathering much of their diet in the form of roots and tubers, seed grains, fruit, berries, nuts and other nutritious plant products. Gould, who spent some time studying the aborigines of the Western Desert, states quite clearly that, 'The diet is primarily vegetarian'. In a very detailed study of the Kalahari bushman's diet it is revealed that: 'The proportions by weight of vegetable food and animal food in the total diet are, respectively, 81.3 per cent and 18.7 per cent. If the plants taken as water sources (such as melons and tubers) are included in the vegetable food count, the ration of animal food to vegetable food is even lower . . . Although the proportion of animal food of the total (18.7 per cent) diet is quite large, the Kade San can survive in the Kalahari without it, whereas they could not survive without vegetable food.'

In fact, out of existing hunter-gathers and those recorded by early anthropologists (before we made them extinct), only the Eskimos / Inuit, living in a climate where they have little choice, eat anything like the proportion of meat we consume today in Western society. This said we can't have it all our own way, there have probably been as few pure vegetarians as 20th century European style carnivores amongst our hunter-gatherer ancestors. Even so, if we go by the evidence of modem hunter-gathers, our ancestors probably ate meat in a more sensible fashion than that of present. Meat tended to be, as we have seen, only a very small part of diet, sauce to make the vegetables and grains more palatable rather than the other way round. Hunter gathers also tend to treat their prey with rather more respect than the way we treat our poor factory farmed, hormone and antibiotic loaded livestock. The Ainu of Japan traditionally pray to the spirits of the animals they kill and ask their forgiveness; similar practice is known amongst both North American Indians and African bushmen.

ARCHAEOLOGICAL EVIDENCE:

Can we tell for certain what our ancestors in the very distant past before the existence of written records ate? Dentition gives us at best only a very rough idea and anthropology provides only possible parallels. Food remains found in the course of archaeological 'digs' are a help but tend to be biased to animal products because, in most conditions, bone is far better preserved than highly biodegradable vegetable matter, if we excavated a Kalahari bush camp, abandoned for the sake of argument for 50 years (a tiny span of time in archaeological terms), we would find bones from the occasionally eaten gazelle but would miss almost entirely the staple “magongo” nuts or the 50 other plants exploited from the desert as food.

Tools used for food preparations may help as well, but flint 'tool' to take one example, have tended to be misinterpreted by meat eating archaeologists. Paleolithic (old stone age) axes originally thought to be butchering tools would have been just as serviceable for digging up root vegetables. In a paper under the title 'Mesolithic Europe - the economic basis', Clark shows how middle stone age people in Britain could have exploited nuts, fungi and a rich variety of plant foods from a landscape which has since become so degraded by human damage, that we have overlooked this vegetarian possibility almost entirely. He goes on to show that flints previously interpreted as tips of hunting arrows, may have components of composite vegetable grating boards!

CIVILISATION

Since the arrival of farming, the written word and 'civilisation' in general some 7,000 years ago, archaeologists have been able to discuss the diet of our more recent ancestors with more certainty than that of earlier stone-age peoples. The Aztecs and Incas combined maize, beans and squash, so that the different amino acids in the maize and beans could be complemented by the carbohydrate content of the squash. Classical India was vegetarian, as was Japan up until only a generation or two ago. The staple of Egyptian workers building the Pyramids was boiled onions, olives, and figs. Pythagoras was a vegetarian, although he had a distaste for beans. Even the Roman army marched on its vegetarian stomach. It is clear that 90% of humanity have subsisted on a 90% vegetarian diet. Modern carnivorous men and women are the exception not the rule.

VEGETARIAN, ken laming, kenneth laming, frugan, health, fresh food, raw food, famous vegetarian, vegan, nutrition, fitness,