Book Review: The Zoologist's Guide to the Galaxy - What Animals on Earth Reveal about Aliens - and Ourselves

I remember many years ago, Animal Planet ran a TV special called "The Future Is Wild."  It purported to show how animals would evolve in the distant future, in a world long after humans have presumably driven ourselves (and many of our cohorts) to extinction.  There were seabirds that basically turned into walruses, squids that swung through the jungle canopy, and spiders that farmed mice for meat.  Even at the fairly young age I was, I remember being highly skeptical.  What are they basing this off of?  I wondered.

If it seems doubtful that we could predict what life in the future of our planet will look like, it would seem impossible that we could predict what life on other planets would be like.   But can we at least make educated guesses?  Cambridge University zoologist Arik Kershenbaum believes so.  In The Zoologist's Guide to the Galaxy: What Animals on Earth Reveal about Aliens - and Ourselves, Kershenbaum takes one small step into the hypothetical.  He postulates that, no matter how different other inhabited planets may be from earth, we will see some striking similarities.  That is because evolution through natural selection is likely to shape species in the same way no matter the planet.  As different as the landscapes may be, any alien animals that we encounter will have much in common with earthling analogs.

Astrobiology, the search for alien life, is mostly more focused on microbes than, say, Vulcans, Wookies, or any of the other fictional alien civilizations that we see in Sci-Fi.  Kershenbaum doesn't spend too much time speculating about alien cultures and technologies, but instead visualizes landscpaes more along the lines of earth ecosystems, with niches for producers, herbivores, predators, and scavengers.  He starts off at the most basic level of form and function - what would these different organisms need to be able to do to survive (find food, avoid being eaten, reproduce) and how would that impact their structures.  We would likely see forms of convergent evolution with earth species, on the grounds that there are only so many ways to do certain jobs and do them well.  Bats and starlings, for example, are not closely related, but both have fairly similar body plans, even though the skeletal structure of their wings are very different, because there are only so many ways that an organism can fly.

From there, Dr. Kreshenbaum looks at other aspects of animal existence to pose a variety of questions about hypothetical aliens.  How will they move?  What sorts of intelligence will they display?  Will they be social or solitary?  How will they communicate and process information?   All of these questions are illustrated with interesting examples from across the breadth of (Earth's) animal kingdom.  In some cases, he explores how things might have evolved very differently on other planets - aliens that might communicate through radio signals, or with an actual, complicated language of scents.  In others, he dismisses some Sci-Fi possibilities as being unlikely to be able to arise through natural selection.

He ends on a more philosophical note, inviting his readers to ponder what the nature of humanity is, and whether it could rightly be applied to alien species that we encounter.  At a time when some humans are pushing for recognition of some species on earth as "non-human persons," it is interesting to consider how we would relate to species from other planets.  He notes that if intelligent aliens from a distant planet - with cultures, technologies, civilizations, etc. - visited us, we would have more (biologically) in common with, say, cockroaches than we would our visitors - but which species would we be most likely to form a real connection with?

Normally I'm not too keen on taking speculation too seriously, but when it comes from such an informed source as Dr. Kershenbaum, it's hard not to be intrigued.  The author admits towards the end of the book that he considers it highly unlikely that we will encounter alien life in his lifetime - and we certainly shouldn't plan on seeing alien species in zoos any time soon.  Which isn't to say that such speculation is fruitless.  As his subtitle suggests, to understand alien life, we first have to devote ourselves to better understanding the life on our own planet.  That's always a worthwhile task, and one where there is still much work to be done.

The Zoologist's Guide to the Galaxy: What Animals on Earth Reveal about Aliens - and Ourselves at Amazon.com