He is currently working extensively on marine metagenomics in the Red Sea, the evolution of viral genomes, the rates of synonymous and nonsynonymous substitutions, positive selection, horizontal gene transfer, genomic evolution, and comparative gene expressions. He has also focused on the evolution of the central nervous system and sensory organs, discovering a vast number of novel genes from the planarian brain and hydra neural cells. He has attained an international reputation as a pioneer of evolutionary genomics, in which he started from the 1980s using viral and bacterial complete genomes. He has also contributed to the DDBJ/GenBank/EMBL database construction as well as the H-Invitational human gene database.