There are three questions that speak directly to human uniqueness and purpose. 1) Does intelligent non-human life exist anywhere in the universe?; 2) Given the fullness of time, will human beings spread across the galaxies?; and 3) Is there something special about this universe that causes or even requires self-aware creatures like human to appear? Today's experts look at humankind and whether the evolution of conscious beings was an accident or a necessity. Joining host Robert Lawrence Kuhn are evolutionary biologist Francisco Ayala; physicist and sci-fi novelist Gregory Benford; Nobel Laureate and physicist Leon Lederman; planetary scientist Bruce Murray; and mathematician Frank Tipler.