Roboticists, by necessity, are keen students of biology: we hope to create machines that are as agile, adaptive and intelligent as the organisms we see around us. However, we tend to copy the end products of evolution (compliant limbs, neural circuits, legged gaits) rather than evolutionary processes themselves (selection pressures, developmental programs). In this talk I will show how re-creating evolution in a computer can allow us to design robots automatically, rather than trying to build them manually.