Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and independently. All animals are also heterotrophs, meaning they must ingest other organisms or their products for sustenance.
Most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago.
Read more about Animal: Etymology, Characteristics, Origin and Fossil Record, Model Organisms, History of Classification, Ethics
Famous quotes containing the word animal:
“I am afraid that the animals regard man as a creature like themselves which has lost its sound animal wits in a most dangerous way—that they regard him as the deranged animal, as the laughing animal, as the weeping animal, as the unhappy animal.”
—Friedrich Nietzsche (1844–1900)
“O animal excellence,
Take pterodactyl flight
Fire-winged into the air
And find your lair
With cunning sense
On some Arabian bight....”
—Allen Tate (1899–1979)
“Labor came to humanity with the fall from grace and was at best a penitential sacrifice enabling purity through humiliation. Labor was toil, distress, trouble, fatigue—an exertion both painful and compulsory. Labor was our animal condition, struggling to survive in dirt and darkness.”
—Shoshana Zuboff (b. 1951)