Genet. Sel. Evol. 40 (2008) 359-378
DOI: 10.1051/gse:2008008

Individual increase in inbreeding allows estimating effective sizes from pedigrees

Juan Pablo Gutiérrez¹, Isabel Cervantes¹, Antonio Molina², Mercedes Valera³ and Félix Goyache<sup>4

1</sup>  Departamento de Producción Animal, Facultad de Veterinaria, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
²  Departamento de Genética, Universidad de Córdoba, Ctra. Madrid-Cádiz, km 396a, 14071 Córdoba, Spain
³  Departamento de Ciencias Agro-Forestales, EUITA, Universidad de Sevilla, Ctra. Utrera km 1, 41013 Sevilla, Spain
⁴  SERIDA-Somió , C/ Camino de los Claveles 604, 33203 Gijón (Asturias), Spain

Received 14 May 2007; accepted 9 January 2008; published online 17 June 2008

Abstract - We present here a simple approach to obtain reliable estimates of the effective population size in real world populations via the computation of the increase in inbreeding for each individual (delta F_i) in a given population. The values of delta F_i are computed as t-root of 1 - (1 - F_i) where F_i is the inbreeding coefficient and t is the equivalent complete generations for each individual. The values of delta F computed for a pre-defined reference subset can be averaged and used to estimate effective size. A standard error of this estimate of N_e can be further computed from the standard deviation of the individual increase in inbreeding. The methodology is demonstrated by applying it to several simulated examples and to a real pedigree in which other methodologies fail when considering reference subpopulations. The main characteristics of the approach and its possible use are discussed both for predictive purposes and for analyzing genealogies.

Key words: effective size / increase in inbreeding / overlapped generation / genetic contribution

Corresponding author: gutgar@vet.ucm.es

© INRA, EDP Sciences 2008