I learned a lot! As clearly written and as engaging as any general science book can be. Maybe a few too many corny jokes, but even those are endearing.

Biggest problem was the tremendous amount of vivisection described very cavalierly; this book is largely about the results of animal research and isn't remotely concerned with the ethics of that.

Even the narrative mindset is way too human-centric for me. Example that made me boggle the most: frog-killing fungus epidemic is described as terrible for "frog lovers" rather than for terrible for frogs.

Oh, many of the endnotes are well worth reading! Lots of little enlightening and entertaining tidbits mixed in with the drier stuff.