A model and algorithm are proposed to infer evolution of a gene family, given the gene tree, with respect to species evolution, given the species tree. The model describes such evolution using the "nested tree" concept. Performance of the algorithm is verified on several orthologous protein groups. The evolutionary events inferred are: speciation, gene duplication and loss, horizontal gene transfer retaining the original gene copy. A transfer event with the loss of original gene copy is considered a combination of gene transfer and loss. The model maps gene evolution events onto the species phylogeny.