The evolutionary origins of present-day eukaryotes. The eukaryotic, eubacterial, and archaebacterial
lineages diverged from one another very early in the evolution of life on earth. Much later, the eukaryotes acquired
mitochondria; later still, a subset of eukaryotes acquired chloroplasts. Mitochondria are essentially the same in plants, animals, and fungi, and therefore are thought to have been acquired before these lines diverged.