All the commonly seen organisms on the earth are eukaryotes, or organisms built up of eukaryotic cells. These organisms evolved from a prokaryotic ancestor and developed over the last 1.4 billion years into the extremely diverse and successful groups of invertebrates, fish, amphibians, reptiles, and mammals. Today, eukaryotes live in a vast array of different environments in almost all areas on the surface of the earth.

Salem Press Encyclopedia of Science, 2022. 3p.