This book is - at least with respect to its basic setup - about two things: (1) whether and how the human race still evolves (per biological evolution; natural and sexual selection), and (2) how this evolution could unfold in the future.
The bulk of the book is devoted to discussing different mechanisms of biological evolution with numerous examples from human history as well as from the animal and plant kingdoms more generally. In addition, the book quite convincingly makes the case that despite "modernization", biological evolution has not stopped in the human race; e.g. genetic evolution through sexual selection may be even more pronounced today as it has been in the past because people move throughout the globe in increasing numbers and therefore mixing of different gene pools happens in greater extend than ever before.
However, the "future humans" content - despite being prominently featured in the book title - is very, very thin. Yes, the author discusses the mechanisms through which future evolution may play itself out (e.g. the effects of diminishing exposure to various beneficial and harmful bacteria in the post-industrial Western world), but there is quite little "end results" speculated about.
Was it good?
My feelings towards the book are mixed. In a way, the book very nicely builds towards the main deliverable: what future humans would be like - the conceptual-theoretical-empirical foundation is very solid.
But then, the main deliverable does not really materialize, which is something of a disappointment. At least I expected to read towards the end of the book about whether we would have, say, larger heads (brains), evolve into several different species and so on, but apparently the author has not dared to venture into such speculations -- the book is published by Yale University Press.
But, in this case perhaps it would have been more honest towards the reader to drop the notion of "future humans" from the title, as the book does not really paint a picture of future humans -- though it excels in spelling out the mechanisms which will bring about those future humans.
The main take-away for me?
Perhaps the main take-away for me was - perhaps a bit paradoxically - how little we know about genetic mechanisms. According to the book, in very many cases it is well-established that genetic mechanisms are responsible for evolutionary outcomes both in short and long term, but next to nothing is known today how those mechanisms precisely operate.
Who should read the book?
The book, in my opinion, should be considered mostly as a good popularized introduction to evolutionary biology and not a account on how future human beings will look like. Conceived like this, the book can be recommended to anyone interested in evolutionary biology. But then again, in this category there probably is not a shortage of excellent popularized accounts, such as those authored by Richard Dawkins, for example.
The book on Amazon.com: Future Humans