The Zoologist's Guide to the Galaxy

What Animals on Earth Reveal About Aliens - And Ourselves

The "Galaxy" and "Aliens" part isn't very imaginative; it is "subset extrapolation" from a partial history of earthlife, focused on macroanimals past and mostly present. Our interactions outside the solar sysem will be one-way-observational for some time; if we discover other intelligences observationally, what we learn will change (some of) us but will be unlikely to change "them".

Complex macroanimals re-emerged 250 million years ago, after the Permian-Triassic extinction. From the zoological viewpoint, our "kind" is 250 million years old, while the oldest observed planets (though not rocky/metal planets like Earth) are 12.8 billion years old. If the first Earthlike planets emerged 10 billion years ago, while Earth emerged 4.7 billion years ago, a few of those planets have a 5 billion year head start on us. Even if few developed intelligence, and far fewer spread out to become a multiplanet species, the nature of exponential growth and the megayear timescale of cross-galaxy interstellar travel suggests the few will grow to become many, and "they" will have a very long time to evolve from their animal(?) ancestors.

Most planet-born intelligences may fail, as we might, in which case there will likely be many more planets with animal life but not intelligence. That's the subject of the book, sorta - it presupposes planetary environments much like Earth, with the potential emergence of intelligence much like ours. Which is mildly interesting, but not very imaginative. Obviously, humanity is creating entropy too fast to keep on as we are for megayears, but if intelligence survives in the solar system for more billions of years, it must adapt to extraterrestrial conditions. Even without human carelessness, terrestrial conditions will end in a few hundred million years.

I think many people will like this book. If I had more time (or fewer books) for leisure reading, so would I. However, it is mostly focused on alien paleo-animals, not the new forms of life that intelligence may invent for itself, mostly to self-evolve past time and resource limits. "Zoologist's guide" indeed; zoology is an observational and classificational science; zoological re-engineering is still in the lab here on Earth.