Knowledge acquisition and the rise of social machines

In this issue Brian Gaines (Gaines, 2012) provides a magisterial review of the origins of human kind and human knowledge. It is a reminder that in spite of all our technology it takes a very special type of scholarship to weave such a compelling narrative over such a monumental range of time and material. This article takes a number of strands of Gaines' arguments and presents them in the context of my own, colleagues and the field's research trajectory. (C) 2012 Published by Elsevier Ltd.