Define Historic Example of Evolutionary quantitative geneticists?

Evolutionary quantitative geneticists have developed tools to create predictions about the short-range evolution of traits that may be correlated with others. (Lynch and Walsh 1998). One of the most basic of these tools is the so-called "multivariate breeder's equation", ?z = Gβ: the modification in one trait (?z) is equal to the selection gradient acting on it and other traits (β) times the additive genetic variance- covariance (G) matrix (Lande and Arnold 1983) (the multivariate breeder's equation is an extension of the easy univariate breeder's equation that has long been utilized as a guideline by plant and animal breeders seeking to select artificially for economically valuable traits). The G matrix describes the patterns of genetic differences of traits and the genetic covariance among traits. Depending on details of the selection gradient and the G matrix, it is possible that a trait may evolve in the opposite direction from the direction it would develop in were it not correlated with other traits. For instance, Conner and Via (1992) examined body size evolution in flour beetles of the genus Tribolium. Selection operating on one character at a time would favor raised pupal weight but decreased male width. As these characters were positively correlated, though, pupal weight increased slightly and male width substantially increased-contrary to the expectation had just one of these traits been under selection.