Ruth Aylett is Professor of Computer Science at Heriot-Watt University in Edinburgh. A robotics researcher for thirty years, she is the author of Robots: Bringing Intelligent Machines to Life. Patricia A. Vargas is Founder-Director of the Robotics Laboratory at Heriot-Watt University, where she is Associate Professor of Computer Science and Robotics. She is coeditor of The Horizons of Evolutionary Robotics (MIT Press).