Tom Chapin

Piranhas - the stuff of nightmares and legends. They're infamous for how fast they can devour prey, and are known to attack in groups of up to 100. National Geographic joins a team of scientists heading to the Amazon to investigate a piranha mystery of immense proportions. A fossil of a giant jaw fragment has been identified as an ancient piranha, but with a terrifying twist: the tooth belonged to a fish seven times the size of existing piranha species.

Animal domestication was a major prerequisite for human civilization to evolve. Join National Geographic as we explore how a dramatic shift from wild to tame happened by investigating foxes, chickens, dogs and rats. Travel to Siberia to see how the physiology of foxes changes when only friendly foxes are bred. In Georgia, follow a scientist as he decodes the DNA of a special population of chickens. And in Moscow, a researcher gains insight into domestication by studying a group of stray dogs.

Massive floods in Australia and Pakistan. Deadly mudslides in Brazil. Epic drought and wildfires in Russia. Historic snows and bitter cold across North America. 2010 was one of the most destructive years in history. Join National Geographic as we present the dramatic images and personal stories of this catastrophic weather year.

They are some of the most lethal substances on earth - transmitted through food, water, the people around you or even the air you breathe. These are bioweapons, strains of bacteria and viruses that include the most feared diseases in human history. Now, imagine that you have just become the leader of your nation and new intelligence confirms that terrorists are trying to make and unleash a biological weapon in one of your cities. What are their chances for success?