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:
“His reversed body gracefully curved, his brown legs hoisted like a Tarentine sail, his joined ankles tacking, Van gripped with splayed hands the brow of gravity, and moved to and fro, veering and sidestepping, opening his mouth the wrong way, and blinking in the odd bilboquet fashion peculiar to eyelids in his abnormal position. Even more extraordinary than the variety and velocity of the movements he made in imitation of animal hind legs was the effortlessness of his stance.”
—Vladimir Nabokov (1899–1977)
“All that is told of the sea has a fabulous sound to an inhabitant of the land, and all its products have a certain fabulous quality, as if they belonged to another planet, from seaweed to a sailor’s yarn, or a fish story. In this element the animal and vegetable kingdoms meet and are strangely mingled.”
—Henry David Thoreau (1817–1862)
“When we understand that man is the only animal who must create meaning, who must open a wedge into neutral nature, we already understand the essence of love. Love is the problem of an animal who must find life, create a dialogue with nature in order to experience his own being.”
—Ernest Becker (1924–1974)