The genetic-background dependence of specific abnormalities and their response to laboratory selection suggested Hsp90 could be an 'evolutionary capacitor', allowing developmental variation to accumulate as neutral alleles under normal conditions and manifest selectable morphological differences during environmental stress.
It may also allow for cryptic genetic variation to accumulate at R-genes.
Finally, we suggest that this neurogenetic class, residing on a disproportionately large fraction of the genome relative to other functional classes, provides a large mutational target for genetic variation to accumulate and selection to act upon.
They argued that Hsp90 is an evolutionary 'capacitor' that creates robustness to the effects of mutations, allowing genetic variation to accumulate in a cryptic form, to be released later.
Canalization implies a reduction in trait variability [ 1, 3], i.e. in the propensity to vary in response to mutations or environmental changes [ 5], whereas it leaves genetic variability unaffected, allowing for cryptic genetic variation to accumulate [ 6].
We propose that a large mutational target [ 85] of neurogenetic genes can explain the rapid evolution of behavior in animal taxa., These neurogenomic loci collectively provide a large genomic substrate for variation to accumulate, and then selection and drift to act, to quickly transform behavior within a relatively short time frame.
The dynamics of homogenisation are analogous to the effects of gene flow: just as reduced gene flow allows variation to accumulate between geographically-separated populations, low levels of homogenisation between different chromosomal loci would allow the accumulation of different ribotypes (see Figure 7B-C).
Through mutation and recombination, genetic variation continues to accumulate over millions of years until the overall level of genetic diversity may approximate or even surpass that of the source (parental) populations (Stuessy et al., 2006).
Allelic variations are expected to accumulate in the absence of genetic exchange between the two nuclei [ 20].
We also show that common laboratory strains of Chlamydomonas widely used as references in mutant comparisons have up to 5-fold variation in their capacity to accumulate oil.
