Abstract
Natural evolution and complex adaptations often surprise scientists. However, the creativity of evolution is not limited to the natural world, transcending any particular substrate. In the context of digital evolution, artificial organisms evolving in computational environments are also able to elicit surprise and wonder. Indeed, most digital evolution researchers can relate anecdotes highlighting how common it is for their algorithms to creatively subvert their expectations or intentions, expose unrecognized bugs in their code, produce unexpectedly potent adaptations, or engage in behaviors and outcomes uncannily convergent with ones found in nature. Such stories routinely reveal the surprise and creativity of evolution in these digital worlds, but they rarely fit into the standard scientific narrative and are treated as obstacles to be overcome rather than interesting results. Bugs are fixed, experiments are refocused, and one-off surprises become stories traded among researchers through lossy, inefficient and error-prone oral tradition. Moreover, to our knowledge, no collection of such anecdotes has been published before and many natural scientists do not recognize how lifelike digital organisms are and how natural their evolution can be. We have crowd-sourced the writing of a paper and collected first-hand reports from artificial life and evolutionary computation researchers, creating a written, fact-checked collection of entertaining and important stories. It serves to show that evolutionary surprise generalizes beyond the natural world, and may indeed be a universal property of all complex evolving systems.