Abstract
Developing a comprehensive theory of open-ended evolution (OEE) depends critically on understanding the mechanisms underlying the major evolutionary transitions; such periods of rapid innovation, such as the Cambrian explosion, have resulted in exactly the kind of diversity and complexity deemed the hallmarks of strong OEE. This paper introduces a new domain for studying major transitions in an evolutionary robotics context. Inspired by the popular Minecraft video game, the new Voxelbuild domain centers on agents that evolve the capacity to build arbitrarily complex block structures with minimal objectives. Initial experiments demonstrate both the rich expressive potential of the new domain and, intriguingly, the occurrence of major evolutionary transitions in at least some runs, thereby providing a unique opportunity to probe how and why such transitions occur or fail to occur in different runs of the same system.