Phenotypic plasticity can facilitate adaptive evolution in gene regulatory circuits

Table 7 Plasticity slows down the frequency increase of circuits in a new optimal genotype network.

N	c	d	Sample size	Mean t_0.25,control	Mean t_0.25,plast	p-value
8	0.4	0.125	498	27.55	46.72	< 2.2 × 10^-16
		0.25	498	30.69	45.91	< 2.2 × 10^-16
		0.5	497	28.01	45.63	< 2.2 × 10^-16
	0.3	0.125	495	18.8	26.49	< 2.2 × 10^-16
		0.25	498	19.25	25.86	< 2.2 × 10^-16
		0.5	498	26.44	25.99	< 2.2 × 10^-16
16	0.25	0.125	413	41.61	106.96	6.9 × 10^-14
		0.25	431	35.66	138.98	< 2.2 × 10^-16
		0.5	418	49.76	162.98	< 2.2 × 10^-16
	0.2	0.125	462	43.4	143.45	< 2.2 × 10^-16
		0.25	466	36.48	133.72	< 2.2 × 10^-16
		0.5	471	42.01	120.97	< 2.2 × 10^-16
20	0.2	0.25	152	35.45	103.8	4.4 × 10^-10

The number of generations that a population needs to increase the fraction of its circuits in the new genotype network to 25 percent is significantly higher with plasticity, i.e., t_0.25,plast>t_0.25,controlaccording to a Wilcoxon signed-rank test.
The value of d is that of the old genotype network. We analyzed 500 pairs of evolving populations for each combination of N, c and d. We discarded population pairs in which any of the populations never had 25% of its circuits in the new genotype network by the end of the simulation (t = 10⁴). Thus, our actual sample size was lower than 500 populations. The probability α of gene-activity perturbation in s₀ equaled 0.05 per gene when N = 8, 0.025 when N = 16, and 0.02 when N = 20. Population size M = 1000; μ = 0.5; ω^native = 0.5.