I tore through this in a couple of days, which says something about how readable I found it. This is the kind of science writing I like, clear enough to be accessible to a non specialist, but not so simplified that I feel like I'm being talked down to or like I'm missing half the data. The writer doesn't pretend to be free of opinons, he says which of various academic theories or arguments he finds most plausible, but he also gives me the gist of the various theories and their supporting evidence so that I can make up my own mind.
Some of what is here wasn't new to me, but it was still interesting and fun to read. I particularly enjoyed the contention that the people of the Americas were actively managing the environments they lived in to make them produce more food. They weren't unspoiled children of nature living in harmony with the wilderness, they were arborists and farmers and managers of game preserves. I found it pretty convincing all in all, and a lot of fun to read and think about.