Human Spark

THE HUMAN SPARK explores one central question: what makes humans unique? Three and a half billion years of evolution have produced uncountable billions of living species. But only one -- humans -- can think in symbols; recombine those symbols into infinite meanings; invent a technology to disseminate the message; worry how others might react to it; ponder the past; speculate about the future; and imagine the unknown. This three-part series is hosted by actor, author and science buff Alan Alda. He travels the world and speaks to a wide variety of experts who share their original thoughts about our most human characteristics. Along the way, Alda forms his own intriguing personal view of what our spark is and where it lies.