Anyone who hasn't read this book is missing out, big time! The author, Peter D. Ward, uses amazing (practically poetic) profundity in explaining the previous three major "mass" extinctions, and then reasons on the current state of the Earth, to show that we are at the beginning of the fourth such major "mass" extinction - and that it's our fault. Seriously, even those of you who are not normally interested in Biology or Geology (like me) should check this book out, because it is awesome. Has anyone here read it? What did you think of it?