An intense scientific debate has ignited around an extraordinary family living in rural Turkey with five adults who walk with their feet and the palms of their hands.

The five siblings were first "discovered" in 2005 by scientist Uter Tan, who created a media sensation by suggesting that the handwalkers might be "genetic throwbacks," offering clues to our early human ancestors. Intrigued by Tan's theory, German geneticist Stephan Mundlos is searching for a genetic mutation that could be connected to why early humans first stood upright. But many leading biologists and anthropologists believe that to view these family members as a kind of missing link is both deeply insulting and scientifically incorrect.

Since walking upright has long been considered a key milestone in the story of human origins, the discovery of this family raises fascinating questions about genes, social upbringing, and the evolution of our species. Is this the anthropological find of the millennium, or simply a unique medical case? NOVA reveals the touching plight of a family whose unusual handicap has thrust them into the scientific and media spotlight.

Special DVD features include: materials and activities for educators; scene selections; closed captions; and described video for the visually impaired.