Which came first – the running or the brain? Running could be the reason humans were able to hunt large game and consume the protein needed for a big brain.

For John Shea, the way we posed our questions about the human spark got him pondering the evolution of our human uniqueness in a new way.

Here John Shea shares a bit more about his research interests – and what it’s like to be interviewed for television!

Scientists are attacking the question of how we became human from a number of new directions – in addition to analyzing the evidence of ancient fossils.

Psychologist Vicky Horner discusses research into chimpanzee cultural transmission. Do chimps have "culture" like humans?

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?