The effects of low-impact mutations in digital organisms

Table 2 Dynamics of mutation and drift for nine logic operations in Avida

Logic operation	Proportion of experiments in which operation arose by mutation	Average maximum frequency in population	Average maximum number of organisms	Maximum frequency observed	Maximum number of organisms observed
NOT	1.0	0.027 (± 0.0062)	97	0.038	134
NAND	1.0	0.017 (± 0.0046)	61	0.028	101
AND	0.95	0.0015 (± 0.00099)	5	0.0036	13
ORNOT	1.0	0.0063 (± 0.0020)	27	0.013	47
OR	0.8	0.00089 (± 0.00091)	3	0.0036	13
ANDNOT	1.0	0.0030 (± 0.0019)	11	0.0072	26
NOR	0.6	0.00053 (± 0.00062)	2	0.0022	8
XOR	0	0 (± 0)	0	0	0
EQU (XNOR)	0	0 (± 0)	0	0	0

Dynamics of mutation and drift for nine logic operations in Avida. Though none of the operations reached high frequencies without a selective advantage, mutation alone produced all operations except XOR and EQU, and many drifted to appreciable frequencies. The simpler operations are best viewed as alternative potential precursors to XOR and EQU.

ISSN: 1742-4682