 Thus, throughout its founding period, ecological genetics was relentlessly supportive of natural selection as unitary explanation for evolutionary change. (Later laboratory research has shown that the expression of the color patterns is sensitive or plastic to the thermal environment during development and thus the gene frequency estimates may be subject to significant measurement error, owing to the misclassification of genotypes. This is yet another source of variation, not accounted for in the Ford analyses. It tends to weaken the link between genotype and phenotype and thereby weaken the relationship between selection acting on phenotypes and the underlying genotypes. In addition, empirical evidence has found, as Wright expected, that temporal fluctuations in population size, large variance among females in fecundity, and sexual selection reduce the effective number to less than half the Fisher-Ford estimate. In addition, more careful studies have reduced Ford’s estimates of the magnitude of the average genic selection coefficient by about two thirds [see Cook &amp; Jones 1996].)