Abstract. The goal of this working group is three-fold. (1) We seek to identify common properties of stochastic-circuit-based biological computation across a variety of biological systems from the gene regulatory networks underlying aspects of the echinoderm body plan to social circuits capturing how individual decision-making strategies combine to produce functional properties of social structure to the nature of neural circuits underlying coherent, unitary behavior at the whole organism level. (2) We will consider how the dimensionality of the circuits can be reduced in a mechanistically principled way to move toward a theory or compact encoding for the output. (3) Using knowledge about the important causal features of the circuits gained in (2), and hence what aspects of the circuit might be legitimate targets of selection, we will ask how these circuits and their associated outputs might evolve in evolutionary, developmental and learning time.