Inbreeding and Variance Effective Numbers in Populations With Overlapping Generations

HE concept of effective population number originated with SEWALL WRIGHT (1931,1938). He and others have calculated effective population numbers for a variety of models of population reproduction. In particular, NEI has presented (NEI and IMAIZUMI 1966) a different formula as a correction to KIMURA and CROW. In this paper, I will argue that the KIMURA & CROW formula is incorrect and the NEI formula is not precisely defined. I will derive equations for both inbreeding and variance effective numbers in models of population reproduction in which birth and death rates are age specific.