The General Resonance Theory of consciousness suggests that all matter is associated with at least some degree of consciousness and vice versa; they are two sides of the same coin. Both are primary.
Inspired in part by Whitehead's "process philosophy," all things are actually processes, not static things. All processes/entities oscillate between potentiality and actuality, mirroring key features of quantum theory.
Resonating processes sync up when close enough and can, when sufficiently synced, result in higher-level conscious entities that combine the lower-level conscious entities into a new whole.
Biology has leveraged faster information/energy resonance pathways that allow for far larger-scale relatively stable-over-time conscious entities.
It is the speed of resonance pathways that determines the size of each higher-level conscious entity in each moment.
Developed by Hunt and Schooler, initially described in Hunt 2011 ("Kicking the Psychophysical laws into gear: A new approach to the combination problem." A major update will be published in 2019 in a paper by Hunt and Schooler that is in press.