In Science this week, researchers at the University of Arizona report that a lateral transfer of fungal genes underlies the red pea aphid's ability to produce carotenoids. Nancy Moran and Tyler Jarvik found that the aphid genome "encodes multiple enzymes for carotenoid biosynthesis" by performing phylogenetic analyses, they were able to show that red aphids have a 30-kb region encoding a single carotenoid desaturase derived from fungal genes, which green aphids do not have.