This book is scary but well-written. George Church has done a commendable job in taking us through the advances in synthetic biology.

When he speaks of transhumans or "Humans +", then you realise we are on the cusp of changes that may alter us. Will the changes be good, or bad? No one knows.

His structuring is excellent, starting from prehistoric times, and taking us into the future.

The explanations are lucid, and the book is well-written.

However, he glosses over the dangers of the advances happening in this field. This attitude is a weakness of the book. ( )

I had no idea biology had made so many advances in the last 20 years: reviving extinct species from DNA; cells from completely synthetic gene sequences; Lego-like DNA kits; DYI gene engineering literally done in people's garages. ( )

Just when I was starting to feel a little self-conscious about my list so far being dominated by graphic novels and children's books, I managed to plow through this tome. Okay, that's an unfair characterization. At times, I was enraptured by this book. I delivered spontaneous lectures to my husband and my co-workers. I posted quotes on Facebook. I engaged in conversation with a cashier who took my money after I spent a lunch period reading voraciously. But to get to these amazing stories, to get to those turns of phrase that were so poetical and profound that I was moved to claim this book as a part of my personal gospel, there was a lot to plow through.

To say this book was uneven would be a master understatement. Church gave himself an ambitious structure -- telling the progress of synthetic biology as a parallel to the processes of natural evolution. It was a wonderful concept, and in the places where it worked it was brilliant. But in other chapters it was so clearly forced that I wished he hadn't bothered. I also found it strange where he chose to explain concepts in great detail (like the chirality of organic molecules) and where there seemed to be no attempt to explain at all (exactly how one obtains sequences of synthetic DNA -- something central to most of the enterprises in his book.) Finally, there are so many mentions of Church's own work, Church's various business start-ups and organizations that eventually it prompted some eye-rolling.

Why, with all this complaining, would I still give this book four out of five stars? Well, because the content is simply amazing. It is hard to walk away from this book and not be awe-struck at what mere mortals have been able to achieve with the tools of science, hopeful for the future, and even a mystical sense of connection with it all. There are amazing stories in here, of synthetic cyanobacteria that can synthesize diesel fuel from the sun, synthetic organisms that can sequester carbon dioxide from the atmosphere in large quantities, scientists working to resurrect species from extinction, possible treatments for cancer, therapies that could render organisms immune to all viruses, and so much more -- an international competition inspiring college students on shoestring budgets to engineer possible solutions to an astonishing variety of problems.

Of course, there are ethical considerations in this work, and there are moments (especially in the very beginning), where Church is annoyingly starry-eyed. But what Church sets out to do here is to impress us with the audacity of his dream. (And how close much of it is to reality!) And I must admit, I'm walking away a little starry-eyed myself. ( )

The field of synthetic biology is a wide-reaching one, whose potential includes everything from engineering microbes to produce petroleum, to bringing the mammoth back from extinction, to perhaps even creating entire new genomes from scratch. It's a fascinating and important topic, and the authors cover some rather mind-blowing possibilities. (Some of which, frankly, seem a little insane. Church seems weirdly attached, for instance, to the idea of creating humans made of molecules of the opposite handedness to the ones used in natural biology. They'd be immune to existing viruses and parasites! Of course, they also wouldn't be able to digest regular food. And they'd probably smell funny. But, hey, those are mere details, right?)

Unfortunately, I don't think the book, in general, is as good as its subject matter. Scientist George Church and journalist Ed Regis wrote it together, and while there's nothing unusual in that, the result in this case feels awkward and lacking in a coherent sense of who its intended audience is. Sections of it are dense and technical and filled with inside baseball details about labs and research and funding. Some of it I had a lot of trouble following, despite having passed a college-level microbiology class. (Although, admittedly, that was a long time ago, and I possibly should have had more sleep before tackling this book than I did. Still.) Other parts read exactly like a magazine article aimed at the nonscientific public. Some parts are a bizarre hybrid of the two, including one notable instance in which a deeply technical chapter features some only vaguely relevant journalist-style human interest bookends tacked on at the beginning and end. Maybe there's a metaphorical appropriateness there, for a book that features so much gene-splicing, but it didn't make for a particularly smooth read. ( )