 This work revolutionized the retrieval of genes in Drosophila and subsequently contributed to progress in metazoan molecular and developmental genetics.He and his collaborators were the first to propose the use of P element transposon tagging to clone the first metazoan RNA polymerase subunit (Searles et al., 1982).This work demonstrated that the P element is a recently invading parasite of the Drosophila genome and gene pool.