The Carl Zimmer books I've read get smaller and smaller. First I read Parasite Rex, which as the name suggests, was about parasites. It was a Copernican attempt to remove animals like humans from the center of the biological universe by showing how badly numbered our large multicellular kind are outnumbered by parasites. Then I read Microcosm which was all about e Coli.

Now A Planet of Viruses is smaller in three respects. First, it is about viruses which are tiny compared to parasites and e Coli. Second, the book itself is just short of 100 pages, really a well-connected set of essays about different viruses. Finally, the book feels smaller in terms of the sweep, depth, and insight that Zimmer brings to it. That said, it is worth reading because it is a fast read and has lots of full color pages with interesting pictures of viruses.

Zimmer starts with an introduction, then he has short chapters on the history and biology of about 10 different types of viruses from the common cold to Ebola, with several other less expected ones in between (e.g., ones that live in oceans and in conjunction with sea algae are responsible for much of our atmosphere). It ends with a conclusion that generalizes on the specific observations about individual viruses. The chapters are well chosen to illustrate a range of biological points.