Fig. 1: The tree of robots.

A taxonomy consisting of the components based on system architecture (grey), embodiment performance (green) and process (blue). a, The robot-fitness-based classification: (i) the fitness metrics that define the green spider plots, namely, the robot fitness spectrum; (ii) the species of an embodiment defined by the overall fitness score plotted over motion and tactility fitness; (iii) genus groups clustering the robot species into process-based fitness categories. b, Hierarchical morphology representation. c, Requirements for process automation that are transferred into the required robot fitness metrics by (i) identification of domain-specific processes; (ii) deduction of the required basic operations; (iii) quality metrics describing the process that define the required embodiment fitness metrics.