New Genes in Drosophila Quickly Become Essential

Abstract

Essential and New Genes can be broadly grouped into two sets on the basis of their contribution to fitness: those that are essential to the life of an organism and those that can be dispensed with. However, the degree of essentiality in evolutionarily “new” genes—genes that have originated in the recent past—is unknown. Chen et al. (p. 1682 ) investigated the origination and evolution of new genes within 12 Drosophila species and found, surprisingly, that over one-third of genes that have originated within the last 3.5 million years show essential function and that these functions are overrepresented during larval development. Approximately the same proportion of older genes was essential, although many of these genes also appear to show enrichment at later developmental stages. These findings challenge conventional wisdom that would claim that essential genes are ancient and conserved among animal taxa.