In the preface of this book, the author states that the question he will investigate is: why were people everywhere? In other words, why and how did homo sapiens and her cousin species populate almost the entire planet in prehistoric times? This is a fascinatingly broad question and the author certainly has the expertise to seek answers in the global archeological and paleontological evidence, which he reviews at a suitable level for a non-specialist audience.

However, I didn't quite find his presentation and his answers intellectually satisfying. It is to some extent understandable that no very definite answers can be given. The prehistoric evidence would probably be overinterpreted if one was to give only one reason for all prehistoric migrations. But in the concluding chapter, titled "why people were everywhere", the author resorts to the rather placid explanation that "humans went everywhere because humans have purpose". I found this puzzling since "purpose" had not been discussed at all in the earlier chapters, and simply concluding that migration and settlement were deliberate hardly explains why it was successful.

Intriguingly, on several occasions in the book the author actually points toward a more informative answer: increased social interaction. He mentions in passing that the extension of range was the product of more complicated social organization, that social relationships are a form of storage, and that similarities in archeological items indicate increasing scale in social systems as prehistoric colonization proceeded. This seems to make intuitive sense. Wider, peaceful social networks and trade would have multiplied the knowledge and resources available to prehistoric humans, which presumably would have aided migration and settlement.

Unfortunately it is hard to say to what extent these claims of expanding social networks are just unwarranted speculation on the part of the author, or actually supported by evidence. The author does not pursue questions of social scale consistently. Perhaps such questions cannot be reliably investigated by paleontological means, but then he could have written so explicitly.

In summary, the present conclusion, which bears little resemblance to the preceding presentation, would probably have been better left unstated. Since the author set out to answer a general question, he could have re-examined his entire argument more critically to find the archeological and paleontological tracks which could lead to general conclusions with real interest.

Great, but a tad complicated. Excellent analysis of a wide-spread characteristic ( )