LECTURE 2 // September 10th, 2012
Four significant periods of societal change
1. Paleolithic: control of fire and started to make tools. Around 2.5 million years ago.
One of the hominines (our ancestors) were able to do these sorts of things,
2. Neolithic: Agriculture revolution. Nomadic lifestyle changed to a settled lifestyle
and along with that came new types of technology and structures that hadn’t
3. Industrial revolution(s): There are people who split these up into multiple
revolutions but it occurred in the mid 1700’s to the 1900’s. Rural life changed to
urban life and there were changes in energy supply.
4. Medical/technology revolution: Happening now (outcomes unknown).
Wrangham: wrote paper on human adaption to control of fire.
• For all animals the maximization of energy gain has direct positive consequences
• How to maximize energy gain? By your diet choice, patch choice, foraging time,
methods of processing food (cooking – the external stomach), Perks of cooked
food is the energy, the food is safer, more accessible, less time chewing your
food, more appetizing.
There are some instances where it’s good that we don’t cook food. For example, fruit is
better to not be cooked because it spreads its seed by organisms eating and excreting
• Every animal species does well on raw food except for humans. Since the advent
of cooked food, we have changed biologically. It’s harder to get energy from food
unless it has been cooked.
• Study in Germany showed that there was an inadequate energy gain for women
on a 100% raw food diet (vegetarian or meat). About 50% of the women acquired
amenorrhea (the absence of a menstrual period in a woman of reproductive age).
Human change has occurred: we have smaller intestines.