David M. Barker (4)

Nicely complemented with images and sidebars, just as the others in this series are, but Barker spent more words than I really wanted to read on how organisms are classified by scientists. And while I appreciated his pronunciation keys, I found the book's overall organization a little hard to follow: I know a lot about archaeans now, but I don't think I'd be able to recall which traits belong to which phyla.