人类进化：2 生而为人

　　In "Birth of Humanity," the second part of the three-part series "Becoming Human," NOVA investigates the first skeleton that really looks like us–"Turkana Boy"–an astonishingly complete specimen of Homo erectus found by the famous Leakey team in Kenya. These early humans are thought to have developed key innovations that helped them thrive, including hunting large prey, the use of fire, and extensive social bonds. 　　The program examines an intriguing theory that long-distance running–our ability to jog–was crucial for the survival of these early hominids. Not only did running help them escape from vicious predators roaming the grasslands, but it also gave them a unique hunting strategy: chasing down prey animals such as deer and antelope to the point of exhaustion. "Birth of Humanity" also probes how, why, and when humans' uniquely long period of childhood and parenting began.