Camels: One Hump or Two? November 15, 2010

Camels were domesticated more than 3,000 years ago, and to this day, humans depend on them for transport across arid environments. They can easily carry an extra 200 pounds (90 kilograms) while walking 20 miles (32 kilometers) a day in the harsh desert. They can travel as fast as horses but can also endure legendary periods of time without food or water. Humans have used camels for their wool, milk, meat, leather, and even dung that can be used for fuel.