Book excerpt: The inspiration for this volume of contributed papers stemmed from conversations between the editors in front of Chuck Hilton's poster on the determinants of hominid walking speed, presented at thel998 meetings of the American Association of Physical Anthropologists (AAPA). Earlier at those meetings, Jeff Meldrum (with Roshna Wunderlich) had presented an alternate interpretation of the Laetoli footprints based on evidence of midfoot flexibility. As the discussion ensued we found convergence on a number of ideas about the nature of the evolution of modem human walking. From the continuation of that dialogue grew the proposal for a symposium which we called From Biped to Strider: the Emergence of Modem Human Walking. The symposium was held as a session of the 69th annual meeting of the AAPA, held in San Antonio, Texas in 2000. It seemed to us that the study of human bipedalism had become overshadowed by theoften polarized debates over whether australo pithecines were wholly terrestrial in habit, or retained a significant degree of arboreality.