The Evolutionary Origins of Hierarchy
Fig 8
Our results are qualitatively unchanged on different problems.
The P&CC networks are significantly more modular, hierarchical, and solve more sub-problems than PA networks on different, hierarchical Boolean-logic problems. For each problem, an example evolved network (specifically, the one with median hierarchy) from each treatment is shown. S2 Fig and S3 Fig show the final, evolved network from each replicate for both treatments on both problems. Note that for the problem on the right, an extra layer of hidden nodes was added due to the complexity of the problem (Methods).