Genetical Research

Interrelations between effective population size and other pedigree tools for the management of conserved populations

a1 Departamento de Bioquímica, Genética e Immunología, Facultad de Ciencias, Universidad de Vigo, 36200 Vigo, Spain
a2 Departamento de Mejora, Genética y Biotecnología, INIA, Carretera de la Coruña Km. 7, 28040 Madrid, Spain


Genetic parameters widely used to monitor genetic variation in conservation programmes, such as effective number of founders, founder genome equivalents and effective population size, are interrelated in terms of coancestries and variances of contributions from ancestors to descendants. A new parameter, the effective number of non-founders, is introduced to describe the relation between effective number of founders and founder genome equivalents. Practical recommendations for the maintenance of genetic variation in small captive populations are discussed. To maintain genetic diversity, minimum coancestry among individuals should be sought. This minimizes the variances of contributions from ancestors to descendants in all previous generations. The method of choice of parents and the system of mating should be independent of each other because a clear-cut recommendation cannot be given on the latter.

(Received December 8 1998)
(Revised June 30 1999)
(Revised October 5 1999)

c1 Corresponding author. Tel: +34 986 812568/78. Fax: +34 986 812556. e-mail: