'Are we alone?'.

... as an expert in animal ecology and communication at the University of Cambridge, [Kershenbaum's] perspective is fascinating.

... provocative.

All this is partly reassuring — but also disappointing. Where much writing on astrobiology is joyously speculative, Kershenbaum is doggedly cautious, building his case from first evolutionary principles. He can be dry. What saves the book are the animal examples.

The book strikes a fine balance, going into enough depth with the science to engage intellectually while never forgetting the fundamental fun that comes with this sort of speculation (the Douglas Adams allusion of the title is undoubtedly intentional). Dr. Kershenbaum gives the impression of a scientist and academic who has managed to maintain his sense of wonder, making him an ideal creator for this sort of work. He takes his flights of fancy, to be sure—and a work like this needs those flights—but even when he sails into the clouds, his feet remain firmly planted upon a foundation of sound scientific thought. Again, it’s all guesswork, but it would be difficult to find a more educated guesser than Kershenbaum.

His expertise in the field of animal behavior adds weight and validity to his arguments.

Included are illustrations of some of Earth’s most fascinating animals, such as the Portuguese man o’ war, as well as insight into their behavior. Throughout, Kershenbaum also provides a thorough review of why life on Earth exists in all of its variety today.

In captivating detail, the author explores how the concept of convergent evolution can be used to deduce how aliens may use language and communication, socialize, move, and develop organic and artificial intelligence.

... entertaining.