When did Humans Begin to Cook?

by admin on April 19, 2009

A look at the problems involved in pinpointing an exact time for the advent of cooking.

Problems with timing and other assumptions

Calculating the exact time of the advent of cooking on a wide basis is extremely difficult, as such evidence from Palaeolithic times is virtually nonexistent, and what evidence exists is easily prone to misinterpretation. Evidence for the use of fire is not the evidence of the use of fire for cooking. Also, many assumptions have been made concerning the effects on humanity as a result of cooking. How accurate are some of these claims?

Fire: Controlled or Wild?

Fire has been part of the environmental landscape of Earth for about 400 million years, and volcanoes and lightning have been sources of wildfires for eons.[1] When and how homonids evolved to eventually acquire the use, then subsequently the control, and finally the production of fire is subject to much speculation. It is erroneous to assume that any evidence of fire from millenia ago, must be of human origin, and then further jump to conclude that humans have been cooking for millions of years. Yet that is exactly what zoologist Richard Wrangham suggests.[2] ( It should be noted that he specializes in chimpanzee research, not human evolution.) In fact, as has been pointed out by various anthropologists, wildfires caused by lightning-strikes are quite common in East Africa, and have been long before our human ancestors evolved to the point of using these natural fires. Another problem with Wrangham’s notion that the advent of cooking was much earlier than generally accepted and supposedly led to larger human brains is that you need a high degree of intelligence in order to invent and control the use of fire, as it is such a complex process. In other words, it takes a big, smart brain to make the fire, not the other way around. Evidence is also clear that humans are the only species to have developed this skill. Considering no antecedent existed for early humans and the high intellect required, it is reasonable to conclude that pyrotechnology was a slow going process historically. Try lighting a fire with with just 2 sticks, the wind blowing around you, while experiencing less than ideal weather conditions. Even without those hindrances, using 2 sticks, as opposed to matches/tinderboxes etc. is a hell of a business. Combine that with the everyday dangers and necessities of survival and it becomes a tall order indeed.

It is inaccurate to assume that human pyrotechnology coincided with the invention of cooking as it makes much more sense, on an evolutionary and logical level, to assume that fire was first used as a way of keeping warm, burning brush and warding off dangerous wildlife. Furthermore, interaction with and use of fire preceded the production of it in early humans.[3] It is interesting that the long-term use of home-based caves circa 400,000 to 350,000 years ago was probably the result of the use of controlled fire for light, warmth and warding off predators, as fire residues are first found around this period.[3] A cave can be a dark and dangerous place in the interior without light to reveal slippery surfaces or hidden predators.

So when did we start cooking? Actual hard evidence, in the form of cooking hearths, is found 250,000 years ago.[4] One source cites a figure of 125,000 years as the beginning of the controlled use of fire by humans for the purpose of cooking food.[4] Most others cite, on average, a figure of about 250,000 years, as being more or less established.[2] Only a mere handful of scientists, like Wrangham claim the far less reliable figures of 790,000 to 2.6 million years ago for the advent of cooking. The first modern form, Homo Sapiens, appeared between 140,000 to 110,000 years ago, which also coincides with the beginning of the last ice age. This drastic change in climate may well have been the trigger for the widespread use of fire for warmth and cooking.[5] It is certainly a more resonable assumption than millions of years prior.

Adaptation to Cooked Foods

Another issue to consider with the history of cooking is the length of time needed for the body to adapt to it. Some geneticists think that it takes circa 1 million years for a particular species to fully adapt, on an evolutionary level, to an entirely new diet (eg: from a Fruitarian to a largely meat-based one) and this view is reflected in our own ancestral, pre-human dietary past where extreme dietary-changes were pretty slow, taking many millions of years in some cases.[5]

Given that cooked food involves a much more drastic change to one’s diet than simply switching from one type of raw food to another – such as fruit to meat – it’s obviously going to take a much longer time to adjust to it, by comparison. Chemical alterations caused by cooking are many, and many of them are known to be harmful (view the many cooked food articles on this site for details). Plus, given that no other animal has ever gone in for cooking its own food, we don’t really know whether any species can ever fully adjust in all ways to such a food. We may be able to tolerate them to some extent, but they are not optimal choices.

It is certainly a more resonable assumption than millions of years prior.adaptation to cooked foodsAnother issue to consider with the history of cooking is the length of time needed for the body to adapt to it. Some geneticists think that it takes circa 1 million years for a particular species to fully adapt, on an evolutionary level, to an entirely new diet (eg: from a Fruitarian to a largely meat-based one) and this view is reflected in our own ancestral, pre-human dietary past where extreme dietary-changes were pretty slow, taking many millions of years in some cases.[5]

Given that cooked food involves a much more drastic change to one’s diet than simply switching from one type of raw food to another – such as fruit to meat – it’s obviously going to take a much longer time to adjust to it, by comparison. Chemical alterations caused by cooking are many, and many of them are known to be harmful (view the many cooked food articles on this site for details). Plus, given that no other animal has ever gone in for cooking its own food, we don’t really know whether any species can ever fully adjust in all ways to such a food. We may be able to tolerate them to some extent, but they are not optimal choices.

Indeed, it has been stated that the advent of cooking also led to us having certain unique dental problems, such as malocclusion, due to eating softer cooked foods; whereas other species seem to be unaffected by these particular problems, due to having a more natural, raw diet.[6]

Switching to the consumption of foods which were softer than before, possibly caused human jaws to become smaller on average, due to lack of natural selection for tougher jaws; but the number of teeth remained the same, thus explaining why a number of humans often need to have their wisdom teeth removed. Some predict that, eventually, human teeth, due to lack of natural selection and a lack of a harder, uncooked, unprocessed diet, might eventually disappear altogether, from our descendants![7]

The research of American dentist Weston Price was conducted in the 1930s on twelve traditional tribes of the modern era, who were isolated from civilized peoples. All twelve ate some raw animal foods as part of their regular diet, some more than others.[8] The Eskimos he visited were traditional hunter-gatherers, untouched by agriculture, who just happened to show a most impressive bone structure with wide faces, ample enough for all teeth, and rarely were any dental caries found in any of their teeth.[8, 9]A description of their general diet follows:

“For the Eskimos of Alaska the native diet consisted of a liberal use of organs and other special tissues of the large animal life of the sea, as well as of fish. The latter were dried in large quantities in the summer and stored for winter use. The fish were also eaten frozen. Seal oil was used freely as an adjunct to this diet and seal meat was specially prized and was usually available. Caribou meat was sometimes available. The organs were used. Their fruits were limited largely to a few berries including cranberries, available in the summer and stored for winter use. Several plant foods were gathered in the summer and stored in fat or frozen for winter use. A ground nut that was gathered by the Tundra mice and stored in caches was used by the Eskimos as a vegetable. Stems of certain water grasses, water plants and bulbs were occasionally used. The bulk of their diet, however, was fish and large animal life of the sea from which they selected certain organs and tissues with great care and wisdom. These included the inner layer of skin of one of the whale species, which has recently been shown to be very rich in vitamin C. Fish eggs were dried in season. They were used liberally as food for the growing children and were recognized as important for growth and reproduction. This successful nutrition provided ample amounts of fat-soluble activators and minerals from sea animal life.”

It is impossible to accurately estimate what proportion of raw to cooked animal foods and plant foods were in the diet of our more recent ancestors during the Palaeolithic Era. It surely would be most interesting to see a long-term scientific study performed of people following a 100% cooked food diet, which may include cooked fruit and cooked vegetables. It would be fascinating to see what the effects would be over a decade or more.

Did Cooked Food Create Bigger Brains?

As for Wrangham’s claims that cooked food consumption led to bigger human brain-size, they are easily debunked.[2] His claims are that Homo Habilis gained brain-size due to including more (raw) meat in the diet, but that Homo Erectus gained extra average brain-size due to eating cooked-foods. Given that the increase in average brain-size was roughly similiar for both species (~300cc for each, or roughly 500 to 800cc for Homo Habilis, 900-1200cc for Homo Erectus), it’s far more likely that the increase in either pre-human brain-size was due to one sole, common reason, namely eating meat, especially since Homo Erectus ate a diet much higher in meat than Homo Habilis, who, in turn, ate more meat than previous ancestors. Also, H. Erectus was a larger animal than its predecessor, and thus, their relative brain sizes are actually quite similar [10] and less noteworthy than the brain size without consideration to overall body size. So, Wrangham doesn’t really have any basis for his ‘cooked foods increased brain size’ argument, and in fact his ideas often contradict the available evidence. most other anthropologists oppose Wrangham, stating that that cooking fires began in earnest barely 250,000 years ago, when ancient hearths, earth ovens, burnt animal bones, and flint appear across Europe and the middle East. Back 2 million years ago, the only sign of fire is burnt earth with human remains, which most anthropologists consider coincidence rather than evidence of intentional fire.[11]

Wrangham suggests that it is the consumption of cooked tubers in particular that led to brain expansion by providing an increase in energy in the diet, but this would place the control of fire much, much earlier than established. [5] It also fails to account for DHA, a vital constituent to brain development, not found in tubers, but found in meat and fat.[12] Also brain-size has decreased by some 8% since the advent of the Agricultural Revolution, which coincided with a massive increase in the consumption of cooked starchy foods [12], so this contradicts Wrangham’s ideas completely. An increase in cooked starches, grains and the introduction of dairy to the human diet, coupled with a decrease in meat has caused great detriment to our species, especially regarding brain size! As stated previously, the invention of fire requires a great deal of intelligence to implement in the first place, and this is why it makes much more sense to assume that human evolution preceded the use/invention of fire, than Wrangham’s ridiculous claim that the invention of cooking, and specifically the cooking of tubers led to larger human brain-size.

Wrangham has claimed that Homo Erectus (being of roughly similiar size to modern humans) would have needed to eat 12 pounds of raw plant food or 6 pounds of raw plant and raw animal food each day just in order to survive.[2]

Wrangham also claimed that eating mostly raw meats would not help as H. erectus would have needed to chew raw meat for 5.7 to 6.2 hours a day to get enough energy. Unfortunately, Wrangham is basing these claims on the chewing-rate of chimpanzees (who he claims chew meat very slowly), and it should be obvious that chimpanzees are quite different from Homo Erectus populations, on an evolutionary level, so that this is not a valid comparison (after all Homo Erectus populations were far more evolutionarily adapted to meat- eating than chimpanzees are today, both are of different sizes etc. etc.)! Also, plenty of anecdotal evidence from the Raw-Foodist community indicates that those on 100% raw diets simply do not need to eat anywhere near the kind of vast, unnecessary quantities that Wrangham has supposedly claimed – and they certainly don’t need to chew from 5.7 to 6.2 hours a day in order to get sufficient calories! Indeed, it’s very common for Raw-Animal-Foodists to need to eat amounts of raw food on a Raw-Animal-Food Diet which are significantly lower in quantity than the amounts of cooked-food they ate previously on standard, cooked diets.

And raw-foodists certainly don’t need to chew for the ridiculously long periods which Wrangham has claimed – indeed, it’s often claimed by Raw-Foodists who follow partially raw diets that cooked food needs to be chewed for a longer period than raw food as they claim cooked food is so poorly digested by their bodies, by comparison.

Conclusion

It’s probably safest to trust the experts in human evolution who have set the advent of cooking at 250,000 years ago, even though there are some credible claims for as little as 125,000 to as long as 300,000 years ago. Dates much older than these have no basis given current archaeological evidence. Furthermore, there is no evidence whatsoever that cooking was instrumental regarding human brain-development (though undoubtedly, in terms of cultural development, later on), and the prevailing evidence clearly indicates that cooking was invented only about 250,000 years ago.

References

1. Pyne, Stephen J. Fire: A Brief History. University of Washington Press, 2001.
2. Gorman, Rachael Moeller. “Cooking up Bigger Brains.” Scientific American, December 2007.
3. Rolland, Nicolas. Was the Emergence of Home Bases and Domestic Fire a Punctuated Event? A Review of the Middle Pleistocene Record in Eurasia, Asian Perspectives: the Journal of Archaeology for Asia and the Pacific pp. 248-280
4. Fire and Cooking in Human Evolution, Rates of Genetic Adaptation to Change, Hunter-Gatherers, and Diseases in the Wild, BeyondVegetarianism
5. Timeline of dietary shifts in the human line of evolution, BeyondVegetarianism
6. Pickrell, John Human ‘dental chaos’ linked to evolution of cooking
New Scientist, February 19, 2005
7. Wilford, John Noble. Human Teeth, Small Already, Keep On Shrinking
New York Times, August 30, 1988
8.Fallon, Sally. Ancient Dietary Wisdom for Tomorrow’s Children Weston A. Price Foundation website.
9. Price, Weston A. Nutrition and Physical Degeneration, 6th Edition. Price-Pottenger Nutrition Foundation, 2003.
10. Jurmain, Robert, Kilgore, Lynn, Trevathan, Wenda and Nelson, Harry. Essentials of Physical Anthropology, 5th Edition. Thomson Wadsworth, 2004.
11. Pennisi, Elizabeth. HUMAN EVOLUTION: Did Cooked Tubers Spur the Evolution of Big Brains?. Science, Volume 283, Number 5410 Issue of 26 Mar 1999, pp. 2004 – 2005
12. Setting the Scientific Record Straight on Humanity’s Evolutionary Prehistoric Diet and Ape Diets. BeyondVegetarianism website.

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