I found the beginning of this book - in fact, the first 8 chapters - utterly fascinating. A clear, intelligent, well-written account of all the essentials of modern thinking on biological and cultural evolution from the emergence of man 1.7 million years ago, thorugh the migration out of Africa (c. 50,000 BC), and up (in fact) to the Neolithic period. The emphasis is on genetics, but not overwhelmingly so -- and in any case, according to author at least (I know nothing about science, to put it mildly), the study of this entire topic has now been revolutionized by the decoding of the genome.
The last few chapters were much less interesting (as other reviewers have also noted) - though the topics are not unimportant: race, language, genetic history of Jews and Thomas Jefferson, etc. Yet they are too technical and too speculative (simultaneously). An attempt (rather meager, imo) to do the genetics of altruism simply did not convince or, ultimately, hold my interest. Hence, the loss of the fifth star in my rating.
Still, for those who want a sound and reliable primer to this topic of the paleolithic, which is exactly what I was looking for - with interesting sidelights on primatology -- this is a great book to start with.