Various historic volcanoes, and the ability to survive them. It includes the Toba volcano, from Indonesia. "The true story of the explosion of the Mount Toba supervolcano, the largest eruption in the past 28 million years, and its lasting impact on Earth and human evolution."-- Some 73,000 years ago the eruption of the Toba supervolcano released the energy of a million tons of explosives; seven hundred cubic miles of magma spewed outward in an explosion, and so much ash and debris was injected into the stratosphere that it partially blocked the sun's radiation, causing global temperatures to drop by five to nine degrees. Prothero presents the controversial argument that the Toba catastrophe nearly wiped out the human race, creating a 'genetic bottleneck' whose survivors could be the ancestors of all humans alive today. -- adapted from jacket