PREDICTION OF RESPONSE TO SELECTION WITHIN FAMILIES

The distinction is clarified between two different uses of the term 'w ithin-family selection', either to imply that one individual of each s ex is selected from each family or to imply that individuals are selec ted on their deviation from family mean, in which case families may no t be equally represented. In the short term, selection on within-famil y deviation is expected to give higher responses, but in the long term , selection within families is expected to give higher responses as th e effective population size is larger. The two schemes are the same, h owever, if only two individuals of each sex are recorded in each famil y.