Its very difficult to predict the functional diversification of paralogus genes. Various secondary metabolites have been produced by the paralogus genes. At present there is no computational method to assess the functions of these metabolites.
Shimizu et. al. (2017) have developed a plant type III polyketide reaction predictor. The method is based on hidden markov model. The software can be freely obtained from the following ftp server ftp://ftp.genome.jp/pub/tools/ppap
Reference:
Shimizu Y. et al. (2017) Descriminating the reaction types of plant type III polyketide synthases. Bioinformatics 33(13) 1937-1943