I call this “typing with cats,” a well known phenomenon amongst cat owners. Any spelling errors, grammatical goof-ups and logical inconsistancies are automatically attributable to “typing with cats.”
Re: * A. robustus *, I once sat and listened to Dr. Johanson lecture for several hours on the importance of teeth in determining the diet of hominids. He felt that said group was clearly vegetarian and I, for one, was not going to argue. Especially in light of the fact that hominid teeth had been his graduate thesis. (Any grad students here will understand.)
I suppose I should clarify my comment on extinction: They went extinct without engendering a new line. Dead end.
Also, (OT), any physical anthropologists here? I’ve been looking for more info on the * K. platycephalus *, but have seen nothing since the original article in Nature.
** Chthonos **, dying isn’t always the only problem with contaminated food and water sources. There are a large number of pathogens that do not cause immediate death but do cause long-term, debilitating illness, as well as shortened life-spans. That is one reason the life-span of humans dropped precipitously once they began settling down.
It might make it easier to digest but cooking destroys many micronutrients so the ‘value’ of the food is less. And we certainly eat raw meat and it does taste better
Remember that cave men weren’t aware of the molecular composition of their food and what happened with macro/micronutrients at the cellular level with the application of heat and what amino acid degradation was; hey - a lot of modern people are still clueless on that one. What ever caused them to start cooking meat was most likely a very simple concept to them. Could it have had something to do with smoking or drying meat to make it last longer (or did that concept come along thousands of years later)?
Just a couple of weeks ago I found a terrific book at the library, and lo and behold despite its ca. 1988 copyright date it’s still in print! It’s called Food in History and includes a very interesting, logically developed (if necessarily somewhat speculative) discussion of precisely the points here.
I’ve heard that cooking meat makes it taste better because it converts some of the simple sugars in the meat into more complex sugars which humans like, perhaps because they remind us of fruit. I haven’t sampled a lot of raw meat (none really, except sushi), but I have compared raw vegetables to cooked vegetables. Sometimes raw vegetables are better than cooked and sometimes they are worse. It depends on the vegetable and my mood.
As far as cooked veggies and meat goes, I’d say they are almost always softer and easier to chew. A lot of times they taste better too.
I’m all for eating plenty of raw food. I think it is good to give your stomach and your immune system a bit of a workout every so often. I do think it is kind of silly to only eat raw food all the time though. I haven’t heard any proof that raw food is healthier yet. For instance, there seems to be some difference of opinion in this thread over whether cooking creates or destroys nutrients (could it be that it does both?).
What about the warming influence of the food? I know that when it’s cold out a bowl of soup or some tea really helps me warm up. This could be a big advantage to humans in cold climates. I don’t think this would be the primary reason they would start cooking food, but it might help perpetuate it in some places.
Frankly, with early man always on the edge of starvation, the macronutrients were a bit more important than micronutrients. The small intestine absorbs cooked meats much more completely than raw meats, unless they’re well chewed organ meats, or extremely well minced pieces of muscle tissue. Otherwise, what passes out of the colon can be up to 2/3 unabsorbed. Primitive man generally didn’t get steak Tartare finely scraped and drizzled with lemon juice and onion on rye bread.
Gram for gram, cooked red meats provide more calories and nutritional benefits than raw red meats under your average paleolithic conditions. This is what my anatomy professor, Alan Walker, taught me at Johns Hopkins. He was a colleague of the Leakeys and researched at Olduvai gorge before becoming a med school professor. It also agrees with what I learned in gastroenterology.
Wait, I don’t understand this. It has been my experience that rare beef is much easier to eat. Cooked or overcooked beef is very tough.
Cooked veggies I can understand. Cooking breaks down the plant’s rigid cell walls and cooked veggies are much easier to eat, but in my experience not beef.
Nor even fish. Raw tuna and salmon I can almost crush with just my tongue on my palate, but cooked tuna and salmon are harder to chew. What changes do the meat go through when cooked?
Energy comes from the breaking of chemical or molecular bonds of proteins. It is fact that chemical bonds store energy and when you break them energy is released. Heating proteins (denaturing) with break some of these bonds, therefore there would be less bonds and therefore less energy. I can only think of a few cases, all of which are inorganic materials, where you can increase bonds by heating. So how can it be explained that cooking red meats will provide more calories?
If you mean to say that cooking red meat makes it easier to digest, then so would pounding it between two rocks.
cooking meat will generally make it more physically available for absorption by the gut. So will pounding it with rocks. Or mincing it fine. But if big bites are taken of raw meat, and it is not chewed really, really well, it is not absorbed as well; the connective tissue inhibits breakdown of the chunk of meat, it’s raw state slows breakdown by stomach acids (or at least the acids work faster on cooked meat) and just not as much will get exposed to the small intestine lining in a form that it can be absorbed.
Well you have explained how breaking down big pieces of meat into little pieces of meat will make it more physically absorbable and provide calories, which is a given, but you still haven’t provided any evidence as to how:
“Gram for gram, cooked red meats provide more calories and nutritional benefits than raw red meats under your average paleolithic conditions.”
The operative words here are “cooked” and “more calories”.
Maybe what you really mean to say is:
“Gram for gram, breaking red meats physically into little provide more calories and nutritional benefits than raw red meats under your average paleolithic conditions.”
To understand this you need to understand the basics of carbohydrate and protein chemistry.
Proteins are made up of long chains of other chemicals called amino acids. Proteins themselves cannot be absorbed into the blood stream, they’re just too big and if the gut allowed big protein molecules in virtually anything, desirable or undesirable would slip through. If proteins ever do enter your body they provoke an immune response in small doses and a shock reaction followed by death in large doses (think bee stings). To overcome these problems the gut digests protein, meaning it simply breaks it down into single (and very rarely two or three) amino acid segments. These move through the gut wall into the blood-stream. Any energy derived from protein comes from the breaking of chemical bonds within the amino acids, not the bonds between them.
Complex carbohydrates such as starch are similar to proteins in that they are made up of long chains of chemicals, in this case chains of sugar molecules. As with proteins complex carbohydrates cannot enter the bloodstream, but are broken down into single and double sugar molecules for absorption. The energy comes from breaking of bonds within, not between sugar molecules.
Cooking denatures protein, breaking it down into smaller chains of amino acids. Starch is similarly broken down by cooking. There’s also a bit of other stuff going on like breaking cross-bridges that’s important for digestion, but we’ll ignore that.
If raw protein is swallowed the gut enzymes and acids have to work much harder to break the food down. These digestive juices are eventually destroyed in the process, forcing the body to waste energy making more. Added to this the gut has to churn more to expose the food to digestive juices for a much longer period of time, and this also uses energy. This explains why cooked protein has a much higher net energy value.
Raw starch from 99% of sources is largely indigestible to human beings. Like chimps we are designed as ripe fruit eaters and carnivores. Fruits contain mostly sugars and oils, very little complex carbohydrate. Eating raw starch will produce much gas, but yield a net negative energy value as the body expels the stuff from the gut. Cooking of carbohydrates from sources such as green bananas and potatoes is essential to derive any nutritional value at all. Even with the few sources of digestible starch available cooking greatly improves the net calorific value by breaking the starch into smaller digestible fragments. Without this process the starch will be largely undigested by the time it finds its way into the colon, after which point it can no longer be digested.
The presence of salivary amylase, which will digest starch, indicates that some human ancestors may have been capable of processing complex carbohydrates, but as things stand our amylases in both the mouth and the gut are fairly inefficient.
As a follow up, physically breaking meat up won’t work for a number of reasons. Firstly I suspect the energy you’d use doing this would be far higher than any additional energy gains. Secondly we’re talking about breaking bonds at the molecular level, and you’d never get anything approaching that fine of a cut without machinery. Thirdly: Are we still doing the ‘Hi Opal’ thing? Fourthly there are some amino-acid bonds or protein cross-bonds that are almost impossible for digestive enzymes to crack. Mincing may break some of these but whatever remained would be indigestible and wasted. So it’s not just a case of mincing meat up really fine. Heating has advantages all its own although mincing and chewing is obviously necessary.
I don’t have any proof of this or anything, but one thing I am absolutly convinced of is that early man/hominoid ancestors were oportunistic feeders. Our ability to survive on such a wide variety of things suggests to me that the eating habits of early man may well have varied widely not just from millennia to millennia but from generation to generation or perhaps even year to year–a band finds a good termite mound, settles down, and a few years later, having depleted it, moves on, hoping to find something else–maybe they find another termite mound, maybe they find a buunch of hyenas to follow around and throw rocks at. I do know that Jane Goodall observed chimps for years–over a decade, perhaps–before she observed the baby stealing/cannibilism episodes that sorta cast a pall over the National Geographic special. Certainly Chimp eating habits are not stable.
I think that any attempt to reconstruct the “typical” lifestyle of prehistoric man is probably taking a backwards approach. I think that hominid flexibility the secret to our sucess. I also think it is interesting that the animal we domesticated long, long before we donesticated any others–the dog–shares our ability to survive on whatever we happen to stumble across.
I’m not sure what it’s got to do with the OP Manda-JO, but you’re almost certainly right. We not only were, but still are very opportunistic feeders, as are chimps. That being said I think that if we can re-construct the fauna and flora habitat of our hominid ancestors, and we know their dentition and dental wear patterns we can easily re-construct their eating habits. They would have eaten anything they could catch and digest, simple as that. If we know what was potentially available we can take a damn good stab at diet. Of course it varied season to season and with location, but the same is true of the diet of cattle, warthogs and duck-billed platypi.
That early humans were nomadic is in very little doubt. Settling in one area for more than one season in a savanna would spell certain death. Certainly settling for years is out of the question. Only the invention of agriculture allowed permanent settlements and all pre-agricultural and many agricultural societies were necessarily nomadic. The only question as this relates to the OP is, at what stage did we discover how to make the indigestible digestible by cooking it, since plant matter and hence agriculture requires fire.
Oh yeah, and termite mounds won’t provide even a small fraction of an ape’s calorific requirements. They’re found every few hundred metres or closer in suitable environments, and nothing would stop travelling just for termites.
Ah yes, Chthonos, one of the Elder Mods, an eldritch assortment of SDMB Deities second only to the Unutterables (known to Eddul al’Zotti, the Mad Editor, as Administrators) in power. Chuck your drugs out the door and watch your behavior while they are about, for they serve The Omniscient One, Ccl, and tolerate no BS.
Getting back to topic, Jared Diamond, author of Guns, Germs, and Steel, wrote an article for Discover Magazine some time ago called “The Biggest Mistake in
the History of the Human Race”. Guess what that mistake was? (No, it wasn’t allowing Pauly Shore to make movies.) It was agriculture. Settling down to an agricultural way of life caused, initially, more problems than it solved. The general standard of living dropped sharply once farming was put into widespread use. Diamond used numerous examples, such as physcial evidence of severe malnutrition and overwork (not present in the remains of pre-agricultural people), the shift from numerous food sources to one starchy root or grass, the concept of despotism (and, eventually, monarchy and feudalism), etc. Disease was one of his main points, and for the reasons you stated. Sorry I can’t find it online.
D’oh! Note to self: Erect small electrified fence around keyboard to prevent small mammals from interfering with typing skills. Wretched feline!
(Derleth, thanks. Yes, I do have a copy of Mr. Diamond’s book but I have not yet had a chance to read it. Yours is the twenty-somethingth good review I’ve heard in the last week, so I’ll try to get to it next weekend.)
Another factor in the agriculture/disease equation was both the domestication of animals and the soil itself. Tuberculosis, for example, is caused by a mycobacterium that grows in soil (as are other diseases which, of course, I can’t remember right now,) and, of course, influenza comes to us from water fowl via pigs. (And lots of other examples that I won’t list here.) For a remarkable read about the history of humans and disease, I would suggest Plagues and Peoples by William H. McNeil. (Um, if you don’t already have a copy.)
However, all these came about long after the discovery that fire could be a tool. Fire was in use well before hominids left Africa.
On that note: those early hominids did not have available the kinds of meat that we do. They lived on the savannah of Africa; not a place renowned for its trout fishing. It may even be that fire was in use before the little flat-heads had taken up hunting, instead of just scavenging. This would mean that they were not getting prime cuts of meat unless they managed to get one of the young of a herd and I, personally, wouldn’t want to take on an angry mother impala.
sigh Great, just great. Now my interest has been re-kindled and I have to go back and re-read all my paleoanthropology books.
[Nitpick]Some of the best fishing in the world is to be found in savannas. Just because savannas are seasonally dry doesn’t mean there aren’t plenty of rivers and streams. Think of the Nile, the Amazon and the Ganges, all of which flow through savannas. Of course the Kakadu wetlands made famous in ‘Crocodile Dundee’ are a classic savanna system.[/nitpick]
The OP asked about “before fire” and fishing is a fairly recent activity for humans. Discover noted this in a February 2001 article saying how the it took fishing to gain the settling of northern Asia (skin color, uv light, vitamin D, folic acid with fish providing the missing elements).
There is a line drawing of three skeketons: Homo ergaster, Australopithecus afarensis and Australopithecus afarensis enlarged to be as tall as Homo ergaster. The main difference between the two is the shape of torsos, ergaster’s is tube-like but A. afarensis’s is pear-shaped. The implication is that a reduced volume of intestines occurred and this could only happen if the food quality improved substantially - meat and marrow and perhaps fire. However fire use may only date from only about 500 ky ago.
Why hasn’t anyone pointed out that there was FIRE, before MAN?