(This review talks about human evolution. If you’re into ID, I’m sure my next post will be full of something not about human evolution.)

Dr. Wrangham is a British Primatologist over at Harvard and his book, “Catching Fire,” is an interesting science book full of nothing but science. He starts with a basic supposition that something happened on the evolutionary boundary between the habilines, largely shown as Homo Habilis and our buddy Home Erectus. By examining the skull structure, chest cavity, molar structure, and the analysis of diet, nutrition and food science, his theory states that humanity made two major jumps:

1. Australopithecine -> Homo Habilis by the introduction of scavenged meat into the diet, well pounded with early tools to make it palatable and digestible.

2. Homo Habilis -> Homo Erectus by placing the vegetables and meat in the fire cook the food.

He marries primatology with food science to show how cooked meat and vegetables greatly reduces the time to chew and digest food while keeping the exact same caloric and nutritional content of food. Experiments show feeding cooked and easy to chew food to animals, especially primates, results in very fat primates who always prefer cooked food to raw. Raw food consumes an enormous time to chew and requires large molars, which Homo Sapiens no longer has, but cooked food needs a smaller digestive system and smaller molars. It also frees Homo Sapiens from the task of chewing all day to doing other things — a rate of spending 60% of the day chewing down to less than 10%. Energy also is conserved in physiology — all animals across all species and genus with access to easily digested food have reduced gut size and put all that energy into increased brain cavity.

Fire provides a whole host of other evolutionary advantages — more hours in the day available to be active, a source of protection at night, a source of warmth, a place for culture to grow and breed, and a clear division of labor between the sexes — hunting and cooking. Dr. Wrangham pulls dozens of examples from many different hunter-gatherer cultures worldwide, from Inuit to Australian aborigines to the !Kung of Africa to South Pacific Islanders, and finds commonalities that involve cooking, meat/vegetable balance, and division of labor and economic trade-offs. All revolves around fire and food.

As for keeping a fire going, experiments show that chimpanzees can keep a fire going indefinitely. If a fire, captured, was brought in to a cave or another protected place and was properly venerated as the God it is, certainly a fire could be kept going. Homo Habilis was a tool-maker and tool-user — if Homo Habilis realized using the gold (pyrite-filled) stones to smash instead of the grey or brown ones, fire would start, and it had enough presence to repeat the process, fire could be made and kept going. It’s reasonable to believe mankind made fire and kept fire far before measured time.

The arguments make sense and they are well sourced with tons of footnotes, a vast bibliography, and references pulled from other sources. The argument is also persuasive — we can find fire pits up to 800,000 years old and after that there is no trace but that means very little. If one little group became Homo Erectus and survived, we would never find evidence of that one small tribe who lived on. Too many evolutionary advantages match with the archeological evidence. Something happened at that boundary between Homo Habilis and Homo Erectus, something that allowed the gut to shrink and the brain to expand and Homo Erectus to spread all over the world. Keeping fire and cooking food makes sense and the arguments are reasonable.

It’s a fairly short, quick read as these sorts of books go at 320 pages. Highly recommended to anyone interested in human evolution and/or food science.