How closely correlated are molecular and quantitative measures of genetic variation? A meta-analysis

The ability of populations to undergo adaptive evolution depends on the pre sence of quantitative genetic variation for ecologically important traits. Although molecular measures are widely used as surrogates for quantitative genetic variation, there is controversy about the strength of the relations hip between the two. To resolve this issue, we carried out a meta-analysis based on 71 datasets. The mean correlation between molecular and quantitati ve measures of genetic variation was weak (r = 0.217). Furthermore, there w as no significant relationship between the two measures for life-history tr aits (r = -0.11) or for the quantitative measure generally considered as th e best indicator of adaptive potential, heritability (r = -0.08). Consequen tly, molecular measures of genetic diversity have only a very limited abili ty to predict quantitative genetic variability. When information about a po pulation's short-term evolutionary potential or estimates of local adaptati on and population divergence are required, quantitative genetic variation s hould be measured directly.