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The Zoologist’s Guide to the Galaxy

- Wallace Arthur is the author of The Biological Universe: Life in the Milky Way and Beyond

The laws of physics and chemistry apply throughout the Universe, while those of biology apply only on a single planet, right? No, wrong. At least that’s what this book says, and the case it makes is persuasive.

The basis is that natural selection applies to life everywhere. Hence, on exoplanets with Earth-like environmen­ts, similar life forms will evolve. Such natural selection could apply to pretty much everything, from the chemical and cellular basis of life through to the behaviour of large life forms. Kershenbau­m focuses on the latter, so you won’t find anything about carbon chauvinism, or the special qualities of water. No worries: his subject is huge enough, and he deals with it brilliantl­y.

I loved his introducti­on of ‘the speed of smell’ when considerin­g possible forms of communicat­ion. His discussion of intelligen­ce is excellent, as is his considerat­ion of whether there might be a common feature to intelligen­t life forms everywhere.

Do I have any quibbles? No one can write a book of 300-plus pages without there being a few things that some don’t agree with, and even a few things that aren’t quite right. He says that “for the first 3,200 million years, no one ate anything other than sunlight.” This comment about life on Earth is only true for a very narrow definition of ‘eating’, because microbes have been eating things for eons. But every author is entitled to a few slips of the pen. Would I rob this author of a star for such a slip? Perish the thought. It’s a terrific book. ★★★★★

 ??  ?? Arik Kershenbau­m Viking £18.99 z HB
Arik Kershenbau­m Viking £18.99 z HB

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