This is a really interesting book. There are so many peaces of information. It really seems to collect a lot of knowledge from different fields of research. At time the author belabors some points. Where he creates contrived examples to explain a theoretical concept.
Some of the fascinating concepts seem to be rooting in minimal data. Such as Homo Sapien tried to come out of Africa twice. The first time they didn't succeed or conquer everthing. The second time they dominated the local species and took over the rest of the world. This is based on some pretty small evidences, although it seems convincing with the backing biology to support it. One evidence is the large species extinctions, all coincide with arrival of modern man.
It is theorized that a single mutation cause man to be able to dream. Then they were able to form large groups, work together, and take over the world. It's really plausible, and that is how evolution is supposed to work. That mutation happened one time, and started circulating the population long ago, might have even been circulating during the first invasion. Those who had it were more fit, and eventually took over the population.
I think this is scary. Imagine, there are actually a sub-population of people who can think better, and more clearly than the people around them. It's such a profound change it is the difference between conquering the world and failing.
It is interesting how he composes the growth of science and capitalism. That the growth of science was perpetuated by this idea of 'we don't know, let's see.'