Inspired by an origin-of- life research program, I (and my colleagues) propose an evolutionary-transition approach to the study of minimal consciousness – the most basic (non-reflective) subjective feeling that includes exteroceptive (e.g. visual, olfactory), interoceptive (e.g. pain, hunger, thirst) and proprioceptive (e.g. bodily position and movement) experiences. Our goal is to identify an evolutionary transition marker for minimal animal consciousness – the phylogenetically earliest overt trait that is sufficient for ascribing minimal consciousness to an animal. We suggest that the transition marker for minimal consciousness is unlimited associative learning (UAL). We characterize UAL at the behavioral and functional levels and argue that the attributes of UAL’s enabling system (the system that enables its developmental construction and maintenance) correspond to the properties that philosophers and cognitive scientists attribute to a system manifesting minimal consciousness. Since UAL had evolved during the Cambrian, we propose that minimal consciousness evolved during this era in the context of selection for UAL.