Example execution segment.

Example excerpt of the execution flow in the counting module of the evolved counting organism's genome. The execution depicted occurs on the map in Figure 1(b), starting from the star and facing north. It covers the organism taking a step forward, turning right based on the cue found there, and then taking another step forward. Exec is the number of instructions that have been executed, Site refers to the position in the genome of the instruction, Instruction is the Avida instruction being executed, Facing indicates the compass direction the organism is pointed on the grid, Flow is the genomic position pointed to by the flow-control head, BX and CX are the values stored in the respective registers and Remarks describes how the instruction operates in its current context. Values that are affected by the current instruction are in bold.