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Back to Coconut Studio Index Page Last updated: 09 May 2006 |
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Seashore Foraging & Fishing Study Early Human Diet | ||
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The Skull & Bones Club - Big Game Meat |
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"The theory of Man the Hunter has never been constrained by fossil evidence" Robert Blumenschine |
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The Neanderthal Enigma - James Shreeve |
"An earlier generation of scholars
sought to explain the role of hunting in the origins of human
behavior and intelligence. It was called "Man the Hunter" after (Lee
& Devore 1968), a book based on a conference on the behavior of
modern hunting and gathering peoples. Sherwood Washburn and Chet
Lancaster's paper in that book attributed many aspects of
modern human social behavior and intellect directly to a history of
hunting large animals. The coordinative and communicative abilities
that are fundamental to the success of a cooperative hunt were
linked to the increasing role of meat eating." |
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In particular, scholars began to model the behaviour of Early Humans on the basis of recent (1970s) field studies of San Bushmen in the Kalahari Desert, where hunter/gatherers were observed to live an idyllic life of easy hunting and social harmony. This idea harked back to Rousseau's idea of the 'Noble Savage', two centuries earlier. Rousseau never actually saw a 'noble savage' in situ. He conceived the whole charming theme in his attic, but it's persisted. There is no evidence whatsoever that early hominids were anything like modern Bushmen, or that they were living in marginal desert areas. |
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It was a seductive idea, fitting well with the notion that humans were somehow special; that they could evolve themselves and develop their brain size and intelligence by simply trying harder. Inventing tools to go out to hunt large animals could have done the trick. "These traits increase the capacity for technology, raising the payoff of intelligence and augmenting the original selective pressure. Hunting becomes the engine of a self-sustaining cycle of social and intellectual evolution". Scavenging and Human Evolution - Blumenschine and Cavallo The meat from the large animals they hunted would somehow have contributed a trigger to feed the expansion of the size and ability of the human brain, starting a feedback process that would result in our extraordinarily large brains. | ||
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But which came first: the larger brain or the ability to use it and hunt ? | ||
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But there are modern parallels to supposed early hunting methods... | |||||
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"The hunters and I are up early. Nine of us--eight of them plus me as observer--are in a small forested valley among rugged hills in a remote part of East Africa. We left together in the darkness of early morning, and now as daylight comes the band of hunters stops on a grassy hillside overlooking a lake. We do not speak, nor can we speak any language the other would understand. I am simply following quietly and taking notes. During breakfast the hunters hear calls from their neighbors to the north, and set off to meet them. We cross a series of ridges, and as the group traverses a stream bed and climbs the valley slope on the other side we see and hear a group of monkeys feeding in a stand of small trees. The monkeys are social and noisy, clamoring about and leaping around in the lower branches. The hunters quickly assess the situation and run to the base of the trees; several begin to climb up toward the monkeys while others remain on the ground below, scanning the treetops. A large monkey falls from the tree while trying to escape and thuds into the dry leaves at my feet. A hunter rushes to grab it, then thumps it against the ground until it is dead. A moment later he steals another hunter's kill with impunity and stands in front of me gripping each monkey in a fist. After several minutes of frenzied action the hunt ends with five monkeys caught. Everyone then sits down around the base of the tree, feasting on the meat they have caught. The hunters politick throughout the meal, sharing and swapping scraps of the much-desired meat. For more than two hours they eat the monkeys, and the noise of bones crunching and contented grunting is all around me. The hunters share the bounty with one another, finish off most of the meal, and then nap for an hour. Every bit of the carcass--including bones and skin--is eaten raw. After they are sated and rested, they get up as if on cue and walk off in search of more food.
This event took place not among a group of African hunter-gatherer people, such as the Hadza of northern Tanzania or the !Kung of the Kalahari desert, but among wild chimpanzees." The Hunting Apes: Meat Eating and the Origins of Human Behavior
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"Carnivory is used broadly here to refer to capture and ingestion of invertebrates and vertebrates regardless of size. Thus, we use the term to identify diet rather than behavior. Since foraging tactics of primates have considerable significance to the overall understanding of primate biology, these tactics are also considered here. Most primates secure animal matter by close-range detection of prey items and capture without chase. Such scavenge-hunting (Hamilton 1973) requires no special predatory skills and is characteristic of omnivorous mammals, including subsistence human hunters. Active hunting, during which prey are actively stalked (Hamilton 1973), is a less common predatory tactic for contemporary primates. Stalking hunting, widely used by diverse predators to secure larger and fleeter prey, so far has been reported for primates only on limited occasions for chimpanzees hunting baboons (Papio anubis (Teleki 1973, Wrangham 1975) and for one population of baboons (P. anubis) hunting infant gazelles (Strum 1975).
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"Charles Darwin was the first to present hunting as the behavioral catalyst that selected for an enlarged brain, tool use, reduced canine teeth and bipedalism, thus splitting the lineages of humans and apes. He laid out his hypothesis in The Descent of Man (1871), before any fossils earlier than the Neanderthals had been found. When more ancient specimens turned up in the early decades of this century, workers linked them directly to Darwin's scheme*." Scavenging and Human Evolution - Blumenschine and Cavallo
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And workers didn't actually link the earliest human remains directly to Darwin's scheme at all. The first really 'Early Man', Pithecanthropus erectus, was discovered in 1891 in Trinil, Java, by Eugene Dubois. Nobody ever suggested that he hunted big game on the savannah. Another 'Early Man' came from Piltdown in Sussex, but the less said about that fiasco, the better |
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"Raymond A. Dart, discoverer of the Australopithecus genus, spent some 30 years trying to show that this hominid could have hunted the animals whose bones were so often found mingled with its own. To circumvent the problem of the absence of stone tools at these sites, Dart invoked an "osteodontokeratic" tool and weapon kit made from a bones, teeth and horn. This interpretation gained popular support in the many accounts of humanity's "killer ape" forebears. It fell apart, however, under the critical tests of the pioneering taphonomist C. K. Brain of South Africa's Transvaal Museum. He showed that the australopithecines had played no role in gathering the bones of the animals found in association with their own skeletons. Instead, these studies suggested, both hominids and ungulates had ended together when the leopards that hunted them discarded their carcasses at the base of their favored feeding trees. Yet the hunting hypothesis remained intact; now, however, it was made to apply to the later stage in evolutionary history that began with the appearance of large brained Homo habilis. |
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The arguments for this theory reached full flower in the papers collected in Richard B. Lee and Irven DeVore's Man the Hunter (1968). The contributors sketched the following scenario. Protohominids encroach on the savanna by eking out their accustomed vegetarian diet with increasing amounts of hunted flesh. Hunting puts a premium on foresight and dexterity, selecting for larger brains and nimbler hands. These traits increase the capacity for technology, raising the payoff of intelligence and augmenting the original selective pressure. Hunting becomes the engine of a self-sustaining cycle of social and intellectual evolution. |
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The Man the Hunter theory prevailed until the late 1970s, when an influential article by the late Glynn Isaac shifted the emphasis from the gathering of meat to the sharing of it [see "The Food-Sharing Behavior of Protohuman Hominids," by Glynn Isaac; SCIENTIFIC AMERICAN, April 1978]. Isaac showed that early hominids had home bases, a behavioral innovation which he argued, implied a sexual division of labor, another innovation. To enhance the omnivorous strategy, males ranged far in search of scavengeable meat or hunted quarry, females gathered fruits and tubers nearer home and families shared the take. Eventually this altruistic behavior and social cooperation began to select for intelligence, language and culture. |
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Then along came an iconoclast and upset the whole applecart. |
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Capsian hunter from Spanish cave wall-painting |
In 1981 Lewis Binford published one of the truly significant archaeological books of the last 30 years - "Bones: Ancient Men and Modern Myths", which further transformed the study of the earliest archaeological sites. During the 1980s Lewis Binford was the big-punching heavyweight of Palaeolithic archaeology. He took on all comers about how the stone tools and bone fragments of the archaeological record should be interpreted. | ||||||
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His strength in debate came from a knowledge about how the archaeological record is formed - the processes of decay and change that affect the items that hunter-gatherers leave behind them in the millennia until they are found by archaeologists. He had acquired this knowledge in the Arctic and the Australian desert where he lived with modern hunter- gatherers, making meticulous records of their activities, what is thrown away and how this would look to an archaeologist.
Binford argued that there was no evidence for the transport and consumption of large quantities of meat. Instead, he suggested that members of H. habilis acquired just tiny morsels of meat, if indeed any at all. They were not merely scavengers, but 'marginal scavengers'. They did no more than take the tit-bit leftovers at the bottom of the hierarchy of meat eaters on the African savannah, trailing in after the lions, the hyenas and the vultures had had their fill. Take away the large meat packages, and Isaac's home bases and his pyramid of inferences come tumbling down. The Prehistory of the Mind - Stephen Mithen | |||||||
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Lew Binford, whose analysis of early hominids at Olduvai Gorge turned them from mighty hunters into marginal scavengers, has only a slightly higher view of their Middle Paleolithic descendants. "At present the inevitable conclusion seems to be that regular, moderate-to-large-mammal hunting appears simultaneously with the foreshadowing changes occurring just prior to the appearance of fully modern man. ..." Binford wrote in 1985. "Systematic hunting of moderate to large animals appears to be a part of our modern condition, not its cause." "All told, there are about a hundred and twenty-five reindeer in (Combe Grenal)," he told me, "along with ninety red deer, seventy-odd horses, and sixteen - that's right, sixteen - bovids. Now, Combe Grenal goes from one hundred thirty thousand to fifty-five thousand years ago. What does that tell you?" 75,000 years of occupation, divided by about 300 medium to large animals - one meat meal every 250 years. "Contrary to what everybody assumes, we are not looking at diet in these early Mousterian sites," Binford explained. "Everybody is imagining this stuff is the product of family meals". "Among modern hunter-gatherer groups, the females are always foraging closer to home. They exploit low-risk resources like plants that they can count on as reliable sources of nutrition for their offspring. The men go after high-risk food, like hunted meat, and they don't always find it." From: The Neanderthal Enigma - James Shreeve |
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And of all the hypotheses about big game hunting (and all the tottering hypotheses that have been built up on that concept) Lew Binford's are about right. After all, he'd actually been hunting with hunter-gatherers, and knew just how difficult it was. Mind you, even he didn't stay around for millennia to find out what eventually happened to hunters' leftovers. |
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The appeal of big game hunting as an important evolutionary force lies in the common assumption that hunting and related paternal provisioning are essential to child rearing among human foragers; mother is seen as unable to bear, feed and raise children on her own; hence relies on husband/father for critical nutritional support, especially in the form of meat. This makes dating the first appearance of this pattern the fundamental problem in human origins research. The common association between stone tools and the bones of large animals at sites of Pleistocene age suggests to many that it may be quite old, possibly originating with Homo erectus nearly two million years ago (e.g. Gowlett 1993). Despite its widespread acceptance, there are good reasons to be skeptical about the underlying assumption. Most important is the observation that big game hunting is actually a poor way to support a family. Among the Tanzanian Hadza, for example, men armed with bows and poisoned arrows operating in a game-rich habitat acquire large animal prey only about once every thirty hunter-days, not nearly often enough to feed their children effectively. They could do better as provisioners by taking small game or plant foods, yet choose not to, which suggests that big game hunting serves some other purpose unrelated to offspring survivorship (Hawkes et al. 1991). Whatever it is, reliable support for children must come from elsewhere. GRANDMOTHERS, GATHERING, AND THE EVOLUTION OF HUMAN DIETS - James O'Connell & Kristen Hawkes This does suggest, doesn't it, that after 2˝ million years of evolution, hunters still don't provide for their families. So why did anyone ever think they started out by doing just that? |
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Just why humans evolved to produce children who contribute nothing whatsoever to the common economic good for at least the first five years of their lives is problem that nobody has got near solving as yet. Besides which, human mothers have to carry their babies around, for up to five years. But, that shouldn't be a puzzle at all. Our local kago (colugo) carries its infant for about the same proportional part of its life as a human mother carries her brat. So bugger all that nonsense about humans evolving to walk upright to carry their children on hunting trips. The colugo flies with its 'teenage' brat. See: Shoreline Mammals In modern society, the most neglected kids are those whose fathers are out drinking or betting. Just how did those whose fathers were out hunting do any better? | ||||
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But the hunting hypothesis comes back again and again, later and later: From about 500,000 BP onwards, Europe saw a continuous occupation by occasionally very small and rather isolated groups of hominins. The typical cold-adapted Neanderthals of the last glacial were the product of a long process of Neanderthalisation that developed during the last half million years under severe climatic stress. Over the last five years archaeological studies have shown that these Middle and Late Pleistocene hominins, in contrast to previous opinions, were capable hunters of a wide variety of large game. Studies of the stable isotopes from their skeletal remains strongly suggest that they were “top-level carnivores”, with animal protein constituting an important part of their diet. But even this is a million and a half years too late for Early Hominids, but just about right for Lew Binford's perception. No isotope studies can identify the size of the animals the 'hunters' ate. Consider Lew Binford's throwaway clue: one meat meal every 250 years
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Hunting's prime purpose is not primarily for food provision. Neither hunting nor scavenging big game could provide enough to feed a family. So maybe all the hunting versus scavenging arguments are irrelevant - nothing to do with human diet, but perhaps more important in social developments. | ||||||
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Costly Signalling | ||||||
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In 1975, Amotz Zahavi proposed a new twist on sexual selection. Males show off to seduce female partners, and sometimes this can assume such ridiculous proportions, as in the case of a peacock's or bird-of-paradise's tail, that it becomes a positive handicap. It not only advertises the male to the female; it also, very riskily, advertises him to his predators. The plus of one doesn't always set off the minus of the other. More than that - while it could show the honest signal that a male can afford to take risks, and will be a fitter mate, it is, after all, a part of seduction, and seduction has never been completely honest, just as there really is no absolute truth in advertising. And the peacock's tail, like a diamond ring, does nothing really. It's just for show. Hunting is also much less about food provisioning than showing off. | ||||||
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Men hunt, and women feed their families | ||||||
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So all the many longstanding and heated arguments about whether early hominids hunted or scavenged their meat are probably almost irrelevant to early human diet.
That they are problems at all may be due only to the social biases of archaeologists. | ||||||
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So, if Early Hominids didn't hunt their big game meat, how else could they have got it? |
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Just How Fruitful is Scavenging? Not very much, it would seem | ||
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James
O'Connell, an anthropologist at the University of Utah in Salt Lake
City, says: If fathers were not feeding their children meat most of the time, that means mothers and, perhaps, grandmothers must have been. Older women might have proved crucial in feeding children, the researchers say, allowing the mothers to get pregnant again more quickly. "Evolution would thus favour a long lifespan, which is closely linked to large body size and delayed maturity. Suddenly, all the major changes in human life history are explained by foraging, not hunting." "Critics point out that even if the meat supply was not reliable enough to live on, it must have been important in evolutionary terms. Humans have been top carnivores - a highly unusual role for a primate - since at least the Stone Age". Man's early hunting role in doubt
Well, of course, mothers were feeding their children. But were they feeding them big game meat? If so, how did they get it ? |
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I originally put this picture here only as an ironical comment. But Kathy Schick, commenting on Oldowan stone tools found in the Middle Awash Valley, remarks how many of them are found with hippopotamus bones. Hippos are not to be trifled with; they are still among the major man-killers in Africa. I doubt that these ladies killed the animal, and I doubt their husbands did, either. I doubt even more that 5ft high hominids hunted such beasts. But a hominid band, living alongside riversides and lakes, would have found a fresh (or just-about-to-be) hippo carcass the equivalent of winning the lottery (and probably just as occasional). Soressi & Dibble - The Biface Book -2003 -PDF on net |
Kavirondo women with hippo lunch | |
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Then, but only then, can you imagine them gathering rocks with glee, chipping them around a bit, and getting to work, leaving the debris of their butchery and dining utensils scattered about, carelessly. See, on this page: HOW TO CARVE AN ELEPHANT Very large aquatic animals have astonishing amounts of meat. Just one Steller's sea cow was said to have fed 33 men for a month at sea (before refrigeration, but men were men in those days, and the only alternative to eating rotten sea cow meat was hard tack and rum). See: Shoreline Mammals |
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Blumenschine's papers on scavenging should give some substantial factual support to his theories, and the long and detailed investment he has put into his ideas. (Sadly, I haven't been able to access the crucial one - Blumenschine & Madrigal, 1993 - can anyone help?). Nonetheless, he has conducted a great deal of worthy and admirable research on such things as wildebeest migrations, leopard kills stashed in trees, etc, to sustain his 'scavenging as meat source' alternative. Most of his field research has been carried out on the Serengeti Plain, familiar to anyone who has ever seen an African wildlife film.
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Then I was sent Martha Tappen's paper, 'Deconstructing The Serengeti'. It gave the answer to just how little regular sustenance could be got from carcasses. She studied bone collections and actively scavenged over a large area of the Parc National des Virunga, a savannah area similar to, but west of the classical Serengeti. Over a period of 4 months she and her team found just 14 carcasses. "Twelve of the carcasses were found while conducting other types of research, four were found while driving/to or from a survey transect, five while working on bone transects themselves, and three during the research of the other members of my "foraging team." Two kills happened so close to us that we heard them occur, and with Land Rovers and park guards it was easy to call these scavenging opportunities, but early hominids may or may not have been able to confront the lions at these kills. More than half of the carcasses (eight) were found by spotting vultures landing on or near the animal while we were doing other research. Only one carcass was found by active search in the Land Rover. Unfortunately, ; I did not collect data on the total amount of time I spent exclusively searching for carcasses by Land Rover, but it was about an hour or two several days a week, or , about 6 hours per week. Only 1 of the 14 scavenging opportunities was found as the result of this active searching. In this study, active searching for carcasses was relatively unproductive (it had a high cost in terms of time and distance with low rates of return). Passive scavenging had dramatically lower costs."
"Long bone marrow, brain, and skin were the only consumable portions left for half of these opportunities" |
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Bone marrow and brains are precisely the foods that 'large-game-meat-favouring' scholars emphasise as the major dietary components that enabled early hominids to grow extra-large brains and obtain energy. A great deal of research has been invested in showing just how stone tools evolved for hacking out bone marrow, and how this led to all the other "emergent social skills, deep planning depth, detailed mental mapping and social cooperation" that made us truly human. |
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"Because early hominids were probably not successful in hunting large ruminants, the scavenged skulls (containing brain) likely provided the greatest DHA and AA (fatty acid lipids) sources, and long bones (containing marrow) likely provided the concentrated energy source necessary for the evolution of a large, metabolically active brain in ancestral humans". Evolutionary Implications for Human Brain Development - available as PDF on internet But this study didn't mention how much scavenged brains would be available. It wasn't a lot.
When, in 1979, cut-marks were found on animal bones at hominid sites, it seemed to prove the case - early hominids ate bone marrow. Rick Potts found cut marks. So did Pat Shipman. And so too did Henry Bunn, a member of Glynn's team. And much research has been done on skeletal part frequencies, age profiles, and cut mark frequencies to prove it. But how much regular bone marrow? And how much regular brain? See a calculation of just how much regular brain at: | |
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It's very likely that some Early Humans ventured from the shoreline into the interior, along rivers, and left sparse remains of their 'big game' feasts just where they found them. Rivers have a strange habit of very suddenly covering everything with flooded mud and sand. So it's not at all unlikely that we should find such remains in 'fluvial deposits' - it's an accident of preservation. But no such occasional preserving accidents can tell us how many Early Humans were doing this, how often, or why. | |
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So - Just How Fruitful is Scavenging? | |
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"The modal scavenging opportunity at PNV is an adult kob with all marrow bones intact, which would yield at least 1600 kcal of high-quality fat. Add to this the fatty brain, and it seems reasonable to use the round number of 2,000 kcal as an estimate of the late-access, passive scavenging opportunity. According to the encounter rate (a find every 9 days) of this study, this late-access scavenging would yield about ... 215 calories a day in marrow and brains. Martha Tappen: 'Deconstructing The Serengeti' | |
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But 215 calories is only 10% of just one average modern human's daily energy requirement, and we're not spending much time running (or even plodding) across savannahs all day. Forget the family and your mates, you'll get about enough to keep you alone going for a couple of hours. | |
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"Scavenging opportunities are too unpredictable and rare to be highly ranked food items for early hominids" Martha Tappen | |
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But What About All Those Huge Carcasses With Stone Tools All Around ? | ||||||||||
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HOW TO CARVE AN ELEPHANT
....A recurrent pattern at some of the world's oldest archaeological sites is the presence of carcasses of "megafauna" (elephants, hippopotamuses) along with simple stone artifacts. For instance, two archaeological sites from Olduvai Gorge in Tanzania have yielded elephant skeletons (an Elephas recki in Bed I and a Deinotherium, an extinct form with downward curving, digging tusks, in lower Bed II). At each of these sites, dated between 1.7 and 1.5 million years ago, an array of Oldowan artifacts was found. At Koobi Fora in northern Kenya as well, parts of a hippopotamus carcass dating to 1.9 million years ago were found with simple stone tools. Two major questions have emanated from such evidence. First... is there a causal relationship between these giant animal bones and these crude stone artifacts? Second...how could the world's simplest stone tools be used to process meat from animals weighing many thousands of pounds, with skins that can be over an inch thick? We have had two opportunities to put stone artifacts to the ultimate test-to butcher elephants (which had died of natural causes). Somewhat daunted, we approached our task equipped with simple lava and flint flakes and cores, which looked more and more paltry as we got closer to the impressive body. Initially, the sight of a twelve-thousand-pound animal carcass the size of a Winnebago can be quite intimidating-where do you start? We had never seen a field manual on pachyderm butchery, and they aren't like smaller animals: you cannot move the body around (for instance, flip it over to get a better vantage) without heavy power machinery.
Although we feel that the butchery of such pachyderms was probably a rare event in the early Stone Age, and probably resulted from scavenging rather than hunting, such experiments demonstrate that the simplest stone technologies can be used to process even the largest terrestrial mammals. Cut marks from stone tools have been found on some Elephas bones at Olduvai, which indicate that stone tools had some causal relationship with the carcass. Since modern scavengers normally do not eat a dead elephant until it has decomposed for several days, such carcasses may have provided occasional bonanzas for early Stone Age hominids, at least until chased away by larger scavenging social carnivores."
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Diet selection by humans follows the pattern of nonhuman primates: Animal matter generally is chosen when it is available and economical relative to other foods (Greenfield 1974). Animal matter comprises, on the average, 14.8% of the dietary energy for contemporary humans (Statistical Office of the U.N. 1971). This value ranges from 2-3% in several populations (that's about the same as chimps) to about 40% in the United States and to more than 50% in New Zealand. Meat is an international status symbol, and 11 “developed” countries consume about 40% of the global meat supply (Greenfield 1974). As the 'developed' countries have about 20% of the world's population, that automatically means they eat twice as much meat per head as everyone else. Internal political decisions are commonly made to provide a larger or cheaper meat supply, and human preference for meat is, thus central to many contemporary economic and political developments. For example, the recent Russian purchases of large quantities of wheat on the world market were not based upon an internal shortage of wheat for bread production; they were used to feed livestock, thereby sustaining the meat-eating proclivities of the Russian populace. Cereal consumption is low in affluent countries, but total utilization is high; a large percentage of this resource is used for livestock feeding (Stamler et al. 1972). Primate Carnivory and Its Significance to Human Diets - Hamilton & Busse 1978 Reading between the lines, meat-eating is for status, not nutrition. Why else have pig feasts? |
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Animal fats and animal protein fed in large quantities to captive primates have atherogenic effects (they give you heart attacks - not a good survival strategy) (see Strong 1976, Strong et al. 1976). The human propensity to expand dietary meat consumption seems to be a legacy from our omnivorous primate heritage. Humans apparently share with most primates a tendency to increase the proportion of dietary animal matter whenever it is economical to do so. We inherited dietary preferences for animal matter, which historically have been limited by economics and a hierarchical society. Under current luxury diet circumstances, no such balance of diet to resource availability prevails and preference betrays best interest. Only religious beliefs or perception of the health hazards of high meat diets will inhibit those with access to luxury diets from developing and maintaining meat consumption at health-hazard levels only briefly attainable by our primate predecessors and hominid ancestors. Primate Carnivory and Its Significance to Human Diets - Hamilton & Busse 1978 |
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The human gut reflects dependence on vegetable food, in particular, relatively non fibrous food. The human colon has the pouched structure typical of herbivores. The large intestine is distensible to accommodate bulk, and relatively long. The human colon absorbs water in food and supports the bacterial fermentation of 'fibrous' plant material, absorbing further energy from ferment products (volatile short-chain fatty acids). We can dismiss significant carnivory as an important factor in human evolution by considering food transit time in the gut. The human gut transit time for food is similar to the frugi-folivorous chimpanzee - about 38 to 48 hours. In contrast, carnivores have a much shorter transit time, from 2.4 to 26 hours (varying with species). In addition, their stomach comprises about 60-70% of their digestive tract volume, in contrast to the omnivorous but plant food 'signatured' humans, whose stomach is about 21-27% of total digestive tract volume. Lorenzo runs After a couple of years trawling the internet for Early Human Diet facts, I find he has some of the very best. But compare this with Aiello & Wheeler's Expensive Tissue Hypothesis |
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Ketone usage as the brain's main energy supply is not limited to humans, but human ability to raise ketone levels in the blood is much better than average. Other omnivores, like rats, pigs, and monkeys can also do it, but to a much lesser extent. Carnivores, such as dogs, achieve negligible ketogenesis. |
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Does this suggest, in any way, that meat-eating was the spur to human brain development? |
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To evolve this extra ketone usage ability, and develop a means of storing its precursors in body fat, a very long-term, stable food supply was vitally necessary. |
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Toothpick Use - This is a perfect example of the kind of circular thinking that characterises the meat-eating paradigm. | ||
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Peter Ungar (who found inter-tooth grooves on ancient teeth) believes that toothpick use became common about the same time meat turned up in the diet of early hominids. Scientists find evidence of pre-historic meat eaters through the sudden appearance of cut marks on animal bones in the archaeological record. This is one of the first lines of evidence from the hominid fossil record that shows our genus consuming significant amounts of meat in the ancient past, Ungar said. "Teeth are not well designed for eating meat, so our early ancestors had to use toothpicks," Ungar said. | ||
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But there may be just one piece of real 'smoking gun' evidence of regular early meat-eating:
Adult worms shed eggs which are then ingested by an intermediate host, usually a particular species of herbivore, such as a domestic cow, some antelope or a pig (domestic or wild). The tapeworm larvae that develops, living in the host’s flesh, pass back into the definitive predator host when it eats the infected intermediate host! They are adapted to this African predatory association. Animal domestication arose about 10,000 years ago. However, the genetic sequence divergence between the two taeniid tapeworms most closely related to the human-infecting species: T. saginata and T. asiatica, gives a divergence date of between 780,000 and 1.71 million years ago. As their ancestor probably already lived in humans, their presence was not due to the domestication of pigs and cattle, but due to some much earlier behaviour. This is a type of smoking gun to our carnivore origins. As the early hominids, Homo habilis and H. ergaster, switched to an increasingly carnivorous diet in Africa, they would have encountered the prey and carnivores carrying these parasites. T. solium, a human-specific tapeworm, is closely related to tapeworms such T. hyaenae (brown hyenas, spotted hyenas and African hunting dogs), T. crocutae (spotted hyenas and African hunting dogs), T. gonyamai (lions and cheetahs) and T. madoquae (jackals). Our hominid ancestors must have occupied a similar ecological niche to these species, relying on similar prey as food. This is good proof that early Homo hunted and scavenged animal carcasses and is supported by archaeological evidence such as the presence of stone tools, cutmarks and hominid-induced breakage patterns on the fossil bones at hominid sites. That the human-specific T. solium and T. asiatica have intermediate hosts that are not antelopes, provides further pieces to our evolutionary puzzle. The intermediate hosts of T. solium are humans, other primates, hares or rabbits, hyraxes, members of the dog family, and wild or domestic pigs (Shipman, 2002). Fossil evidence shows that around 1.7 million years ago Homo ergaster left Africa and colonized Eurasia. This would have led to Homo ergaster encountering new prey species and new carnivore competitors, upsetting the usual predator-host cycling for the parasite that could have led to the extinction of the parasite. However, selection pressure led to humans also becoming the intermediate host for the parasite to survive. (An alternate hypothesis, that the early hominids were intermediate parasite hosts as regular prey to these carnivores breaks down due to the specificity of T. solium for humans.) The hares, rabbits, hyraxes and pigs need to be eaten by early humans for this association to exist, while the dog could have scavenged around human camps and preyed upon these species and so picked up the same parasite. However as the primary host, it is human activity that defines the distribution of these parasites. The intermediate hosts of T. asiatica are the domestic pig and cattle, so this species evolved under selective pressures associated with the domestication of these species. |
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I've transcribed this article in full, in the hope that some reader may understand the logic of it. 1. T. saginata and T. asiatica diverged between 0.78Mya and 1.71Mya. T. saginata is not mentioned again. 2. T. asiatica has domestic pigs and cattle as hosts, but evolved late, with domestication. 3. T. solium is closely related to African carnivore species, and has hosts that are not big game, but humans, other primates, hares or rabbits, hyraxes, members of the dog family, and wild or domestic pigs. 4. H. ergaster 'left Africa' about 1.7Mya, and somehow this led to selection pressure also making humans intermediate hosts, as well as primary ones. How does this lead to: This is good proof that early Homo hunted and scavenged animal carcasses ? | |
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The Tapeworm Letters don't prove a great deal about hunting or scavenging , and in fact seem to disprove that early hominids ate antelopes or other large game very regularly, since those animals don't host the specific human species. They do show that early humans regularly ate some of the much smaller animal foods also eaten by hosts of closely related worms, such as lions, cheetahs, jackals, hyaenas and hunting dogs. And that food comes from the specific intermediate hosts - other humans, primates, hares, rabbits, hyraxes, dogs, and pigs. All those foods (including other humans and dogs) have been, and still are, eaten regularly by humans. Watch this space - I'm now got the original paper, and Pat Shipman's take on it, and trying to work it out. | |
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The timing of the tapeworm split is interesting - between 780 and 1.7Mya. That's a long spread for a definitive date, but the earlier one is when Homo erectus/ergaster is generally supposed to have arisen in Africa, and spread out to Asia and the edges of Europe. But the intermediate host animals are as much Asian/Arabian as African, suggesting that Homo erectus perhaps originated in Asia (where far more of his remains have been found) and then 'went back' to Africa. | |
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On the other hand, if Homo erectus had left Africa following the shoreline, he would have met almost identical prey species nearly all the way to Peking, avoiding the tortuous logic of: ... Homo ergaster encountering new prey species and new carnivore competitors, upsetting the usual predator-host cycling for the parasite that could have led to the extinction of the parasite.. |
Was Homo erectus the Asian immigrant who brought human tapeworms back to Africa? |
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Perhaps you've got the feeling that I (and many others) don't really believe in the generally-accepted myth that Early Humans descended from the trees onto more open ground, begun to hunt or scavenge the red meat of large animals, and thus took the first steps towards becoming as human as we are. Of course I don't. But I am not saying that Early Humans never ate big game meat, because they probably binged on it when they came across it. And I don't say they never hunted, because some obviously did - in the last 100,000 years or so. But they didn't do very much of any of that during the first 95% of human existence.
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If very occasional big game meat (hunted or scavenged) really wasn't the dietary catalyst that got humanity moving along its path to perdition, what was? We are pretty sure that early hominids were omnivores - they ate anything they could lay their tiny hands on, so we'll look at: |
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New Pages as at May 2006 |
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Two unfortunate experiences of Filipino culture: |
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Back to Coconut Studio Index Page
Richard Parker - Siargao Island - November 2005 (Last updated Tuesday, May 09, 2006)
I welcome comments or corrections on my site and opinions, so please feel free to email me at: richardparker01@yahoo.com
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