What is the nature of human uniqueness? In a three-part series to be broadcast on PBS in 2009, Alan Alda takes this question personally, visiting with dozens of scientists on three continents -- even undergoing an examination of his own brain.

Biography of Alan Alda, host of the television series "The Human Spark," coming to PBS in 2009.

Alan gets a highly detailed scan of his brain. This image is the starting point for a search within his brain – as well as the brains of others – for the essential components of the Human Spark.

Alan Alda sets out to explore the difference between chimpanzees and ourselves, and quickly finds that the scientists studying chimps and other non-human primates are themselves separated into opposing worldviews.

Where and when did the Human Spark first ignite? In the caves of France, where 30,000-year-old paintings adorn the walls, as archeologists have long believed? Or at a much earlier time – and on another continent?