Empirical Demonstration That Structural Gene and Morphometric Variation of Mandible Traits Are Uncoupled between Mouse Strains

Abstract

The relationship between morphometric and structural gene variation was examined in a group of 15 inbred mouse strains. The genetic distance of Nei was calculated between each of the strains based upon 36–78 biochemical loci. Mahalanobis distances based on 11 mandibular measurements were computed between the strains as well. The correlation coefficient between genetic distance and metric distance was low ( r = 0.24 ± 0.1). Genetic distance was highly correlated with elapsed time of divergence of the strains ( r = 0.73 ± 0.15) while morphometric distance, though clearly heritable, was not significantly correlated with elapsed time. These results indicate that morphological change and biochemical change are poorly coupled in these strains and suggest that the cumulative differences in structural gene mutations may provide a more accurate measure of phylogenetic relationships between biological groups than do measures of morphological distance (such as mandibular characters) based upon multivariate analysis.