At last some hints at answers to those human questions: How and, even more interesting, Why did we get to this place in our mental development.



The authors present a very readable, straightforward explanation of hominoid evolution including some very humorous cartoons and asides. The inevitable professional jargon is softened by repeated explanations and a comprehensive glossary. The readability of this material is no small feat due to the complex, interactive nature of the various development trends and the forces driving them. The interpretation of the archeological data by itself is extremely impressive. For example: finding piles of flakes resulting from knapping stone tools and reassembling the flakes to figure out the knapping sequences. They learned a lot by comparing how knapping techniques changed over the last 400,000 years and thinking about the minds required to produce and use those tools.



They describe a development path started by a change from sleeping in trees to sleeping on the ground and include some explanations of sleep characteristics we retain from our tree sleeping times. Some food vs. anatomy trade-offs explain how humans developed bigger brains without being burdened by a much longer digestive tract.



Despite being very conservative with their theories we get a believable story of a very recent (30,000 years ago) change that enhanced our brain's working memory and enabled an executive function that allows us to appreciated what's going on in the mind of another human and make complicated plans for things that haven't happened yet.



Learning about this recent change in our brains, knowing that humans began to domesticate plants and animals just a few thousand years ago and then looking at where we are today makes me wonder about the effect of current evolutionary pressures and where the next little change might take us.