Cooking, Fire and Human EvolutionEvolution — POSTED BY Joe Mellen on July 26, 2010 at 2:14 pm
Did Learning to Cook Push Our Ancestors Toward Modernity?
It has long been a fascinating puzzle to scientists: Why did our apelike ancestors come down from the trees and develop brains many times larger than they actually needed? Many theories have been discussed, most of which revolve around social cooperation; big brains would have helped our ancestors develop language, make better tools, plan hunting strategies, and pass on complex culture to the next generation.
The Quest for Fire
It is not currently known when early hominids began controlling fire. Estimates range from half a million years ago to as recently as the Upper Paleolithic, though a large consensus has advocated for a date about 200,000 years ago, just as the modern Homo sapiens was beginning to emerge. The first discovery of fire was likely accidental, but possible archeological evidence of controlled fires made by our progenitors as well as by Neandertals begin to appear as early as 400,000 years ago.
While it is unclear whether these early fires were used to cook food, Wrangham argues that even if no cooking was yet taking place, the mere act of keeping a fire at a campsite would have had enormous consequences. Fire would have kept predators at bay, allowing our vulnerable ancestors to sleep on the ground, rather than in trees as other apes do. This ground living could explain some of the anatomical changes early hominids eventually underwent, such as the loss of climbing efficiency, and the lengthening of the legs and flattening of the feet, which facilitated upright walking.
From Australopithecus to Homo Erectus
One of the greatest questions in human evolution remains: What caused the large and relatively rapid leap from the apelike australopithecines to the more modern Homo erectus and on to H. sapiens? Richard Wrangham and others think the major cause might have been using fire to cook food, pointing out that many of the physical differences between the species point to this conclusion.
Cooking, Calories and Big Brains
Perhaps the most compelling evidence for the cooking hypothesis lies in our enormous brains. Brains are extremely costly organs to operate, and most other species on the planet get by just fine with far less brain power than humans employ, suggesting that extra brain tissue is too expensive a luxury, and generally not worth the energy needed to run it. But eating cooked food — which is something wild animals rarely, if ever, do — has a distinct advantage. Cooking not only makes food easier to chew and digest, it also allows more energy to be released for use in the body.
Several studies have borne this out. For example, a 1990 Belgian study showed that cooked eggs released 91-94% of their protein to be used as fuel by humans, whereas raw eggs released only 51-65%. Conversely, a German study on the effect of a raw food diet on humans found that a third of the subjects, despite eating enough calories, became dangerously underweight and energy deficient, and half the studied women experienced amenorrhea due to insufficient BMI. Cooking food seems to power up its caloric punch, though the reason for this is still unclear. In the modern West, this is a recipe for chronic obesity, but in the early days of hominid evolution, anything that increased the energy value of food would have been a tremendous boon, allowing us to feed our bodies and have calories left over to fuel the growth of our gigantic brains.
Cooking as the Basis for Civilization
Richard Wrangham further theorizes that control of fire and cooking may have been the basis of modern civilization. A dependence on foraged food and hunted meat that was prepared and cooked primarily by women might have been the catalyst for pair bonding and small family units. Additionally, sitting around a fire for safety and to share food might have rewarded cooperation and tolerance, making larger societies possible.
Leave a Reply
You must be logged in to post a comment.