@article{houle_1992, title={Comparing evolvability and variability of quantitative traits}, volume={130}, number={1}, journal={Genetics}, author={Houle, D.}, year={1992}, pages={195–204} }
 @article{houle_1991, title={Genetic covariance of fitness correlates: What genetic correlations are made of and why it matters}, volume={45}, DOI={10.2307/2409916}, abstractNote={-The genetic variance-covariance matrix, G, is determined in part by functional architecture, the pathways by which variation in genotype influences phenotype. I develop a simple architectural model for G for two traits under directional selection constrained by their dependence on a common limiting resource. I assume that genetic variance is maintained by mutation-selection balance. The relative numbers of loci that play a role in acquiring versus allocating a limiting resource play a crucial role in determining genetic covariance. If many loci are involved in acquiring a resource, genetic covariance may be either negative or positive at equilibrium, depending on the fitness function and the input of mutational variance. The form of G does not necessarily reveal the constraint on resource acquisition inherent in the system, and therefore studies estimating G do not test for the existence of life-history tradeoffs. Characters may evolve in patterns that are unpredictable from G. Experiments are suggested that would indicate if this model could explain observations of positive genetic covariance.}, number={3}, journal={Evolution}, author={Houle, D.}, year={1991}, pages={630} }