Model organisms are dispersed across the tree of lifeThe tree shows evolutionary relationships among the major groups of organisms: Bacteria, Archaea, and Eukaryota (plants, fungi, and animals).
[(Clockwise, from top, center) Sinclair Stammers/Science Source; SciMAT/Science Source; Darwin Dale/Science Source; Biophoto Associates/Science Photo Library; Imagebroker.net/SuperStock; © blickwinkel/Alamy]