In recent years, genome-wide association studies (GWAS) have been widely adapted into species other than human, e.g. model species such as Arabidopsis thaliana 1,2,3,4 and Drosophila melanogaster 5,6.

Bivariate survival models with discretely distributed frailty based on the major gene concept and applied to the data on related individuals such as twins and sibs can be used to estimate the ...