Simulation of data aiming at the estimation of variance components and heritability

Ângela Mello COELHO[1]

Décio BARBIN1

§    ABSTRACT: The main aim of this work was to compare methods of estimation of heritability for the 1-way classification and the 2-way crossed classification without interaction. To achieve the established aim, a data set with known heritability was used, produced by simulation. Two methods of estimation were compared: the analysis of variance method and the maximum likelihood method. 80 simulations were made, 40 for each classification. After the 80 simulations were performed, each one obtaining 1,000 data sets, and therefore 1,000 estimates of each component of variance and the heritability, the means for each set of 1,000 estimates were obtained and comparative graphics, for the two methods, were made using those means, using as reference the values of the parameter used in the simulations. For both models the analysis of variance method proved to be more accurate for the estimation of variance components and heritability, considering the groups of simulation used in this work.

§    KEYWORDS: Heritability; variance components; analysis of variance method; maximum likelihood method; estimation; simulation.



[1]Departamento de Ciências Exatas, Universidade de São Paulo, campus de Piracicaba – ESALQ/USP, CEP 13418-900, Piracicaba, SP, Brasil. E-mail: debarbin@carpa.ciagri.usp.br