CR pg. 81 #1

Wrangham links the use of mastering fire for cooking around 1.9 million years ago because humans have not had a substantial development in the way our bodies digest food since then.  By cooking food, it becomes softer thus letting humans develop smaller jaws and less teeth.  Also the male and female relationship, where the male protects the female's food in return for a portion is explained by the relationship of cooking and using fire.  Women could also quit nursing children at a younger age thus giving the woman more energy and allowing her to have more children at a sooner time.  He also suspects that because humans receive so much more energy because cooking our foods increases the ability to receive more calories from a smaller amount of food we are able to divert some of that extra energy to our immune systems thus increasing our life span.  Also more energy allowed us to develop more expensive organs such as our brains but it also made our intestinal system for efficient by making our stomachs smaller and increasing our small intestine to absorb more nutrients.