SELECTION THEORY AND EXPERIMENTAL RESULTS

Abstract

Forty-two years ago this fall, when Dr. Lush and I were both young men, he gave me his point of view on: “How selection changes the genetic composition of a population”; “How selection changes a population — the outward results.” I also heard for the first time about what came to be known later as: “Aids to selection” i.e., “The use of lifetime averages,” “Pedigree estimates” and “Progeny tests.” I heard a good deal about Dr. Lush's basic thinking on topics which he later developed and which formed the substance of the now classical titles such as: “The number of daughters necessary to prove a sire” (Lush, 1931a); “Genetic aspects of the record of performance work with swine” (Lush, 1931b); “Linebreeding” (Lush, 1933a); “The bull index in the light of modern genetics” (Lush, 1933b); “Progeny test and individual performance as indicators of an animal's breeding value” (Lush, 1935); “Intra-sire correlations or regressions on dam as a method of estimating heritability of characteristics” (Lush, 1940); “The optimum emphasis on dams' records when proving dairy sires” (Lush, 1944); “Family merit and individual merit as bases for selection” (Lush, 1947); “Heritability of quantitative characters in farm animals” (Lush, 1949) and many more titles which most of us know by heart.