I once heard author Jared Diamond speak about his book “Collapse: How Societies Choose to Fail or Succeed.” As he was addressing Easter Island, a once forested isle that was eventually denuded by its inhabitants (leading to their demise), Diamond wondered aloud about the last tree. What must the guy who cut it down have been thinking?

Now, as the global human population exceeds seven billion, and we watch real and potential cataclysm unfold around us—civil war, collapse of ocean and tropical ecosystems, global warming, storms and floods, the emergence of new pathogens, nuclear holocaust—I can’t help but  ponder the eventual extinction of our species. And I can’t help but wonder what it will be like for the last man or woman left standing….