Photo Essay: Seeking Humanity's Roots
East Africa's rift valley is considered by many to be the cradle of humanity. In the Turkana region of northwest Kenya, researchers Christopher Lepre and Tanzhuo Liu of Columbia University's Lamont-Doherty Earth Observatory are cooperating with colleagues to study questions of human evolution, from the creation of the earliest stone tools to climate swings that have affected developing civilizations.
June 08, 2016