科学家们利用DNA技术证明所有的人类拥有共同的祖先，为此他们来到人类的摇篮——东非。 Scientists use the DNA from a random group of people to show that all humans share common ancestors. On a single day on a single street, with the DNA of just a couple of hundred random people, National Geographic Channel sets out to trace the ancestral footsteps of all humanity. Narrated by Kevin Bacon, The Human Family Tree travels to...