Average performance of functions OR, AND, and EQU by organisms evolved from Ancestor2. Ancestor2 performed each function only once per reproductive cycle. (A) Evolved performance of OR and EQU. (B) Evolved performance of AND and EQU. See the legend to Figure 2 for description of the points and error bars. All 100 populations lost OR in the +EQU/-OR environment, and all 100 populations lost EQU in both the +OR/-EQU and +OR environments. Also, all 100 populations lost EQU in both the +AND/-EQU and the +AND environments. However, only 47 populations lost AND in the +EQU/-AND environment.