Instinct for survival: Ways we've tried to stave off apocalypse

A South Korean man buys "Y2K Emergency Set" box, in a store in Seoul, South Korea on Dec. 27, 1999.

Svalbard Global Seed Vault built to store seeds and protect them from natural disasters or nuclear strike, Longyearbyen, Norway, as seen in this photo taken on Feb. 25, 2008.

An armed guard walks through the Svalbard Global Seed Vault, built to store seeds and protect them from natural disasters and nuclear strikes in Longyearbyen, Norway on Feb. 25, 2008.

Cyril Houri, as owner of Safer America, demonstrates the Evacuchute system, a parachute for high-rise office workers, in this photo dated Aug. 27, 2003.

Disaster goods for protection during earthquake on shelves in Tokyo, Japan, as seen on Aug. 31, 2000.

A stockpile of survival ration crackers from the "Cold War" era in store room under the Brooklyn Bridge, New York, seen in this photo dated March 21, 2006.

Middle school students climb ropes during winter survival camp, Seoul, South Korea, in this photo dated Jan. 1, 2001.

Middle school students grimace pulling tires during winter survival camp in Seoul, South Korea, on Jan. 3, 2001.

A gas mask, chemical suit, gloves, alarm, multipurpose emergency tool, flashlight and water canister as part of Quark International Limited's urban survival kit, as seen on Feb. 14, 2003.

British Royal Marines practice Arctic Wilderness Survival training in this photo dated Feb. 7, 1998.

A Swiss Army knife showing tools, including an integrated 128MB USB Memory Stick, as seen in this photo on March 23, 2004.