Wednesday, December 07, 2011

Book review: Catching Fire, by Richard Wrangham

Five Stars.

This book was recommended by an evolutionary biologist and is written by an evolutionary biologist and primatologist but the Dewey decimal system in the library categorizes it as a cooking book. Admittedly, I was a bit disconcerted to find it next to Anthony Bourdain's latest tome, but Catching Fire is a gem: easy to read and presents a simple hypothesis with exquisite supporting evidence regarding the social and physiological evolution of hominids.

The basic premise is that Australopithecines developed the ability to process food by mashing and pounding 2.5 million years ago which led to the transition to Homo habilis, the "handyman", who had a larger brain and shorter gut.  The evolution was effected by easier digestion of food which enabled habilines to extract more energy from food sources.  Homo habilus learned how to control fire about 1.9 million years ago which brought about relatively rapid evolution to Homo erectus, a robust species marked with even greater cranial size and short, efficient gut.  This efficiency of calorie extraction allowed greater cognitive ability but also the ability to travel long distances.  Fire affects food in ways that make it easier to digest and therefore more calories are available.

We are evolved to eat cooked food as evidenced by our short gut and the development of taste for cooked food.  Other primates such as chimpanzees also prefer cooked meat although they have not evolved specifically to eat cooked food.  Wrangham hypothesizes that this is due to the easier digestion and the higher caloric extraction from cooked and processed food versus raw food.  He gives a fairly detailed and worthwhile description of how various food sources are affected by mashing and cooking...take that Bourdain! 

Fire also allowed hominids to live on the ground since it afforded greater protection from predators and led to migration across savannahs, increasing the available habitat.  Homo erectus was a robust and long-lived species that survived over a million years in harsh, predator-filled environments.  They lost their hair/fur since they were able to sit and sleep by fire; this enabled them to dissipate heat when running and allowed long distance running.  Fire changed the social relationships between sexes and communities enabling beneficial division of labor and shaping the roles we still have to some degree today.  It all started with the control of fire. 

Darwin recognized the control of fire as "probably the greatest [discovery], excepting language, ever made by man," and Wrangham develops this thesis with strong supporting evidence from anthropological studies of hunter-gatherer societies as well as observations of lower primates.  

Wrangham discusses the biochemistry of food calorie availability and remarks that the current system of calorie determination is flawed since it does not take into account the processing of food.  Cooked meat contains denatured protein which is easier to digest than raw meat.  Likewise, cooked vegetables and seeds are easier to digest and therefore contain more available energy than raw food.  Wanna lose weight? It's simple, eat raw food which burns more calories in digestion for the fewer calories that are liberated.

Catching Fire is an intriguing, well-written book which answers a lot of questions about how and why we enjoy food and how fire affected nearly every aspect of our physical and social evolution.  It's a short readable book, and gets my highest recommendation. 

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