Table 1. Glossary of parameters and their standard values.

Parameter	Description	Standard val.
Z	Population size	105
Mini	Number of phenotypic genes in the founder individual	2
Nini	Number of regulatory genes in the founder individual	10
L	Number of cis-sites in a cis-regulatory region	102
m	Size of DNA sequences that are recognized by a transcription factor.	7.14
n	Possible number of DNA motifs that are produced by m base pairs of DNA sequence	9950
c	Fitness load per unit of gene expression	10−5
V	Level of steady-state constraints on the phenotypic expression	10−4
μBTL	Basal transcription-level mutation rate (per gene per generation)	10−6
μCIS	Cis-regulatory mutation rate	10−6
μTRA	Trans-regulatory mutation rate	10−6
μDEL	Gene deletion rate	10−6
μDUP	Gene duplication rate	10−6
μHOR	Horizontal gene transfer rate	0