In a new study, researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science examined how the interaction of two genomes in animal cells—the mitochondrial and nuclear genomes—interact to affect adaptation of the Atlantic killifish to different temperatures. They showed that although these genomes are separate physical entities, the mitochondrial genome affects the evolution of the nuclear genome, the genetic material responsible for variations in most traits such as hair color and height.