See what other people said they think makes us human. Then, share YOUR spark in text, photos, artwork, or video.

A Web site called Test My Brain lets you participate in online experiments and get feedback about how you compare to other online participants.

Producer Graham Chedd thought a chat en plein air would add some visual variation from the two-guys-sitting-on-a-couch-type shot that's always easy to get in a professor’s office.

Submit your drawings, photos, videos, or text that answer the question, "What makes us human?" Your responses will be posted on this web site, and a selection will appear on-screen during the broadcast!

The media has jumped all over this beautifully preserved 47-million-year-old fossil, with some even calling it a “missing link.” What do you think?

Harvard's Marc Hauser has coined his own term for what we’ve been calling the Human Spark – humaniqueness.

Amanda Henry showed us how she very gently scrapes dental plaque from the Skhul 5 skull’s molars to find out what our ancestors may have eaten.

Harvard's Dan Lieberman argues that we humans evolved to become the best long-distance runners on earth -- and we did it barefoot!

The colors a species can perceive is dictated by the types and number of visual pigments found in the retina. How might our color vision system have evolved?

Language is central to Steven Pinker's conception of what makes us human.