Razib Khan One-stop-shopping for all of my content

October 19, 2010

Did cavemen eat bread?

cavebread

Food is a fraught topic. In How Pleasure Works Paul Bloom alludes to the thesis that while conservatives fixate on sexual purity, liberals fixate on culinary purity. For example, is it organic? What is the sourcing? Is it “authentic”? Obviously one can take issue with this characterization, especially its general class inflection (large swaths of the population buy what they can afford). Additionally, I doubt Hindus, Muslims and Jews who take a deep interest in the provenance, preparation, and substance of their food are liberals. What Bloom is noticing is actually a general human preoccupation which somehow has taken on a strange political valence in the United States. Somehow being conservative in this country has become aligned with a satisfaction with the mass-produced goods of the agricultural-industrial complex.* Some conservatives such as Rod Dreher have pushed back against this connotation, lengthily in his book Crunchy Cons.

Stepping away from politics, we are a diet obsessed culture broadly. Apparently Christina Hendricks is going on a diet, her aim being to lose 30 pounds. Diet fads come and go. The Atkins approach has faded of late, with the Paleolithic diet coming into fashion. A totally separate market segment, that of raw food, remains robustly popular. This was obvious when Richard Wrangham came out with Catching Fire: How Cooking Made Us Human; raw food enthusiasts would call in to talk shows where he was a guest, sometimes irritated that Wrangham was claiming that cooking was central to the emergence of modern humanity. His contention that raw food practitioners were healthy precisely because they don’t process as much of their nutritional intake because of the relatively coarse character of what they were consuming was clearly discomfiting to many of them. This is because it is at variance with some of the rationale for their diet. They are not cooking the food in part because they believe that that removes a great deal of nutritive value.

ResearchBlogging.orgI was thinking about this while reading What is Global History? Offhand the author mentions bread-making as early as 20,000 years go in the process of asserting that many of the preconditions for an agricultural mode of production were already in existence before the end of the last Ice Age. I was surprised by this fact, having never encountered it before. Unfortunately there wasn’t a footnote which I could follow up on, so I thought no more of it. Imagine my curiosity when I stumble upon this paper in PNAS, Thirty thousand-year-old evidence of plant food processing:

European Paleolithic subsistence is assumed to have been largely based on animal protein and fat, whereas evidence for plant consumption is rare. We present evidence of starch grains from various wild plants on the surfaces of grinding tools at the sites of Bilancino II (Italy), Kostenki 16–Uglyanka (Russia), and Pavlov VI (Czech Republic). The samples originate from a variety of geographical and environmental contexts, ranging from northeastern Europe to the central Mediterranean, and dated to the Mid-Upper Paleolithic (Gravettian and Gorodtsovian). The three sites suggest that vegetal food processing, and possibly the production of flour, was a common practice, widespread across Europe from at least ~30,000 y ago. It is likely that high energy content plant foods were available and were used as components of the food economy of these mobile hunter–gatherers.

One of the researchers on the team gave a good quote to Reuters:

“It’s like a flatbread, like a pancake with just water and flour,” said Laura Longo, a researcher on the team, from the Italian Institute of Prehistory and Early History.

“You make a kind of pita and cook it on the hot stone,” she said, describing how the team replicated the cooking process. The end product was “crispy like a cracker but not very tasty,” she added.

The contents of the paper are somewhat dry and opaque to me. The crux of the matter is that there are obviously important reasons why plant materials which may have been present in prehistoric camps aren’t preserved, so there has long been a bias in this area. It seems that the authors found a primitive system of pestle grinders, as well as flour grains. Below are the important figures which show their results:

The Reuters piece takes a shot at the Paleolithic diet:

The researchers said their findings throw humankind’s first known use of flour back some 10,000 years, the previously oldest evidence having been found in Israel on 20,000-year-old grinding stones.

The findings may also upset fans of the so-called Paleolithic diet, which follows earlier research that assumes early humans ate a meat-centered diet.

Ajlun_BreakfastI don’t know how the Paleo enthusiasts will react to this. I’m actually a guarded fan of Gary Taubes 2002 article in The New York Times Magazine What if It’s All Been a Big Fat Lie? I believe that a strong bias toward refined carbohydrates in your diet is bad for you. I generally don’t go as far as the Paleo enthusiasts in my own diet, but I have many friends who believe in the diet, and it works for them. That being said some of the Paleo people have an evangelistic aspect that probably is the source of shots like the ones above in the article. I am 5′8 and in the 140-150 range, usually in the 140-145 range. I’m not fat, and I’m not Paleo. My blood sugar levels are good. It can be done. Just because you were fat or or unfit and a particular diet works for you doesn’t mean everyone else has to follow the exact same prescription to the T. Human variation matters. South Asians have much higher propensities toward type 2 diabetes than other groups. It follows from that that everyone need not follow the nutritional and lifestyle guidelines of South Asians to get the same odds ratio of developing type 2 diabetes. How guilty you should feel about dessert is a function of the biological cards you bring to the table.

The importance of human variation, genetically and culturally, is relevant to this paper. What exactly does the likely presence of flour in three sites in Europe ~30,000 years ago tell us? Granting the validity of these results we can reject a strong form of the model of a Paleolithic diet which excluded processed starches. Does this now mean that Paleolithic humans were toasting pitas constantly around the fire? I don’t necessarily think so. We don’t know how pervasive this practice was. Human societies vary. Just because they were ancient, and “primitive,” does not mean that all Paleolithic populations were all the same. Second, it sees plausible that Paleolithic man was a generalist with a more diversified diet, all things equal, than his peasant successors. It may be that during the Paleolithic era there were no staples in a way we’d understand it today, rather, they subsisted on what was available at any given time. Perhaps these ancient pitas were reserve sources of sustenance which preserved well when other gathering and hunting had little or no yield. The difference between the Paleo-man and the peasant may then be thought of as the latter making what was once an emergency ration which was a good source of calories in a pinch into the staff of life.

A more general moral may be that we need to rethink our model of a Neolithic Revolution. It may have been a Neolithic Evolution.  After the last Ice Age there were at least two independent, and likely more than two, domestication events and shifts toward an agricultural lifestyle. In The Long Summer and After the Ice Brian Fagan and Steven Mithen both imply that the emergence of behavioral modernity during the last Ice Age set the stage for the inevitable shift toward agriculture with the climatic change. So was it was (warm weather) + (modern cognitive capacity) → agriculture? Perhaps. But almost certainly humans were developing skills and competencies over time up until the end of the Ice Age, and with the warmer conditions the switch toward more proactive and intensive cultivation of grains may have been a gradual process of escalation. As population densities began to rise it seems a model could be posited whereby a positive feedback loop was being generated; non-agriculture sidelines were less and less effective as larger populations supported by semi-agricultural lifestyles made greater demands on the local ecology. This may have meant that the shift toward obligate agriculture was inevitable once it became the only viable option. Once the ratchet moved forward there was no going back, and humans had entered a new epoch.

20080818jackfruitToday we live in a consumer age of plentitude. Or at least you live in a consumer age of plentitude if you’re reading this weblog on a computer. We have great choice in goods and services, and can have a wide range of experiences. The past was truly a strange and exotic place; as evidenced by the reality that pre-modern folk took high infant mortality for granted as an unfortunate fact of life, while we today see the death of an infant as a tragedy of the highest caliber. But we mustn’t oversimplify the past. In one episode of the 1989 television series Alien Nation the human protagonist is learning about the religious customs of his partner, an alien. Offhand he mentions his growing awareness to another acquaintance who is also an alien. He then asks if she will be celebrating a holiday he has just learned of, and she responds that she does not believe in that religion. The detective expresses great surprise that the aliens have different religions, to which she quips, “Don’t you?” The point is that the aliens are perceived as an amorphous mass, profoundly different from humanity, and their own internal distinctions are elided in the minds of humankind. And so I believe occurs with human societies of modes of production fundamentally different from our own. “Paleolithic humanity” becomes a type, all difference and variation removed from our conception. “Hunter-gatherer” is distilled down to an image of N!xau from The Gods Must Be Crazy. To get a better handle of how the world is and how it was we need to be careful of this cognitive bias.

Citation: Anna Revedin, Biancamaria Aranguren, Roberto Becattini, Laura Longo, Emanuele Marconi, Marta Mariotti Lippi, Natalia Skakun, Andrey Sinitsyn, Elena Spiridonova, & Jiří Svoboda (2010). Thirty thousand-year-old evidence of plant food processing PNAS : 10.1073/pnas.1006993107

* Just to be clear, I am not personally an unalloyed enthusiast for “natural” methods, whether it be organic or small-scale farming. Rather, I am pointing to the fact that agricultural subsidies have distorted and reshaped the nature of food production, distribution, and consumption. I see nothing fundamentally conservative about being sanguine about the power and influence of the agricultural-industrial lobby, and the corporations which exist in symbiosis with government largesse.

Image Credit: Wikimedia Commons, Serious Eats

Note: Since this post mentions diet I may get some crazy unhinged comments because I know that some people take their diets very seriously, and react harshly to deviationists from the Truth Path. If you have commenting privileges and lose control and post something inappropriate, I will delete it.

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