Animal

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:

    ‘Tis said that courage is common, but the immense esteem in which it is held proves it to be rare. Animal resistance, the instinct of the male animal when cornered, is no doubt common; but the pure article, courage with eyes, courage with conduct, self-possession at the cannon’s mouth, cheerfulness in lonely adherence to the right, is the endowment of elevated characters.
    Ralph Waldo Emerson (1803–1882)

    Your cravings as a human animal do not become a prayer just because it is God whom you ask to attend to them.
    Dag Hammarskjöld (1905–1961)

    The animal is one with its life activity. It does not distinguish the activity from itself. It is its activity. But man makes his life activity itself an object of his will and consciousness. He has a conscious life activity. It is not a determination with which he is completely identified.
    Karl Marx (1818–1883)