This book was recommended by a member of the Anthro-L email list. I've subscribed to this list for more years than I can remember now. It's part of my effort to keep my brain active. This book was described as very readable with a lot of insight into the processes and conditions associated with those critical moments for life on this planet when everything changes. This link is to Google Books and not all of the book has been made available.

http://books.google.com/books?id=jYSZgaaxRv0C&lpg=PP1&pg=PP1#v=onepage&…