In the red section of the genome (left), the gene acts as a capacitor, allowing cryptic genetic variation to accumulate. In the black section of the genome, variation is fully expressed, and most is purged. When the gene is knocked out, abundant cryptic genetic variation is revealed, and a smaller amount of previously expressed variation is made cryptic. The red and black sections are shown as equally large, indicating that the wild type is not necessarily more robust to new mutations, on average, than the knockout .
Masel BMC Biology 2013 11:103 doi:10.1186/1741-7007-11-103